S

• S chemical symbol, sulfur; symbol for siemens and svedberg; [L.] semis (half); sight; [L.] signa (mark); [L.] sinister (left).

• S phase see cell cycle.

• S₁ first heart sound created at the beginning of ventricular systole by the closing of the atrioventricular valves. See heart sounds.

• S₂ second heart sound created at the end of systolic contraction of the ventricles when the semilunar valves close. See heart sounds.

• S₃ third heart sound created by reverberation of the ventricular walls during early diastolic filling. Can be indicative of heart disease, particularly dogs. See heart sound.

• S₄ fourth heart sound created during the last phase of diastole during atrial systole. Can be indicative of heart disease in dogs and cats, but often heard in healthy horses. Absent in horses with atrial fibrillation. See heart sounds.

• Σ sigma, capital letter; 18th letter in the Greek alphabet. A mathematical symbol for sum.

• σ sigma, small letter; 18th letter in the Greek alphabet. A mathematical symbol for standard deviation.

• S-A, SA sinoatrial.

• S-T segment the portion of an electrocardiogram between the end of the QRS complex and the beginning of the T wave. It represents the period of repolarization of the ventricles.

• S1-mapping a method for mapping precursor or mature mRNA to particular DNA sequences using the enzyme S1-nuclease.

• SA node see sinoatrial.

• Saanen a breed of all-white, although cream is acceptable, dairy goat with prick ears and always polled.

• Sabin–Feldmann dye test [sa′bin feld′m n] a test that detects serum antibody against Toxoplasma gondii. In the presence of antibodies, live organisms are not stained with methylene blue. Called also methylene blue dye binding test.

• sable 1. a coat color pattern with black-tipped hairs on a light background. Seen in the German shepherd dog. 2. breed of fur rabbit; see American sable.

• Sabouraud’s dextrose agar [sah-boo-ro′] see Sabouraud’s dextrose agar.

• sabulous [sab′u-l s] gritty or sandy.

• saburra [s -bur′] sordes; foulness of the mouth or stomach.

• saburral [s -bur′ l] pertaining to saburra.

• SAC Scottish Agricultural College.

• sac [sak] a pouch; a baglike organ or structure. See also conjunctival sac.

• air s. 1. alveolar sac. 2. one of the large air-filled diverticula of the respiratory system of birds. See also air sacs.

  • allantoic s. see allantois.
  • alveolar s’s the spaces into which the alveolar ducts open distally and with which the alveoli communicate.
  • anal s. see anal sacs.
  • endolymphatic s. the blind, flattened cerebral end of the endolymphatic duct.
  • heart s. see pericardium.
  • hernial s. the peritoneal pouch that encloses a herniated viscus or mesentery.
  • lacrimal s. see lacrimal sac.
  • paranal s. see anal sacs.
  • pleural s. the pleura-lined cavity that contains the lung.
  • ruminal s. one of the dorsal and ventral sacs of the rumen that are themselves further subdivided to create a caudodorsal sac and a caudoventral sac. Formerly called saccus dorsalis, saccus ventralis, saccus cecus caudodorsalis, saccus cecue caudoventralis, respectively.
  • yolk s. the extraembryonic membrane connected with the midgut; in vertebrates other than true mammals, it contains a yolk mass. See also yolk sac.

• sacahuiste, sacahuista Nolinatexana, N. microcarpa.

• saccade [s -kād′] small, rapid, involuntary, jerky movements of both eyes simultaneously, such as occur in humans while reading and all animals when focusing attention on a fixed object during head movements.

• saccadic [s -kad′ik] characterized by saccades.

• saccate [sak′āt] 1. shaped like a sac. 2. contained in a sac.

• saccharated iron, saccharated ferric oxide a brown powder, soluble in water, used as a hematinic. Given by intramuscular injection to newborn piglets. See also iron poisoning.

• saccharide [sak′ -rīd] one of a series of carbohydrates, including the sugars; they are divided into monosaccharides, disaccharides, trisaccharides, and polysaccharides according to the number of saccharide groups present.

• sacchariferous containing sugar.

• saccharogalactorrhea secretion of milk containing an excess of sugar.

• saccharogenic capable of producing a sugar.

• saccharolytic [sak″ -ro-lit′ik] capable of splitting up sugar.

• saccharometabolic [sak″ -ro-met″ -bol′ik] pertaining to the metabolism of sugar.

• saccharometabolism [sak″ -ro-m-tab′o-liz- m] the metabolism of sugar.

• Saccharomyces farciminosum [sak″ -ro-mi′sēz] see Histoplasma capsulatum var farciminosum.

• Saccharomycopsis guttulatus [sak″ -ro-mi-kop′sis] see Cyniclomyces guttulatus.

• Saccharopolyspora rectivirgula a thermophilic actinomycete that produces spores in moldy hay. The spores are inhaled by cattle eating the hay and cause granulomas and bronchitis, bronchiolitis, and a chronic interstitial pneumonia. It is also associated with chronic obstructive pulmonary disease in horses.

• saccharum [sak′ -r m] [L.] sugar (especially sucrose).

• sacciform [sak′sľ-form] shaped like a bag or sac.

• Saccostrea glomerata farmed bivalve; called also Sydney rock oyster.

• saccular [sak′u-l r] pertaining to or resembling a sac.

  • s. stage lung growth about the midpoint of fetal development when the lung volume increases markedly due to saccule development; subdivision of the saccules into alveoli commences.

• sacculated [sak′u-lāt″ d] containing saccules.

• sacculation [sak″u-la′sh n] 1. a saccule, or pouch. 2. the quality of being sacculated. 3. the formation of pouches.

  • large intestinal s. see haustrum.
• saccule [sak′ūl] 1. a little bag or sac; a small, pouch-like cavity. 2. the smaller of the two divisions of the membranous labyrinth of the vestibule, which communicates with the cochlear duct by way of the ductus reuniens.

  • laryngeal s. the pouch-like cul-de-sac of the laryngeal ventricle especially when of large size. Former terminologies distinguished between the entrance to the laryngeal ventricle and this, its pouch-like extension. The current NAV makes no such distinction. The entrance in most species lies between the vocal and the vestibular folds. In pigs the ventricle lies between the two parts of the vocal ligament, and there is no sac in the cat nor in ruminants. Called also ventriculus laryngis.
• sacculectomy surgical removal of saccular structures.

  • anal s. performed in dogs with anal sac disease. It is also the basis for descenting of skunks and ferrets. There are a number of different procedures described, many of which are modifications intended to enable the surgeon to more easily visualize and handle the structures.

• sacculitis [sak″u-li′tis] inflammation of a saccule, e.g., airsacculitis, anal sacculitis.

• sacculus [sak′u-l s] pl. sacculi [L.] a saccule.

  • s. laryngis see laryngeal saccule.
• saccus [sak′ s] pl. sacci [L.] a sac.

  • s. cecus the blind sac of a viscus such as the fundus of the stomach in the horse.
  • s. hypophysialis an outgrowth of ectoderm coming directly from the roof of the stomodeum in the embryo; it comes into contact with a downgrowth from the forebrain and is later transformed into the anterior lobe of the pituitary.

• sacrad [sa′krad] toward the sacrum.

• sacral [sa′kr l] pertaining to the sacrum.

  • s. dysgensis see sacrocaudal agenesis.

• sacralgia [sa-kral′j ] pain in the sacrum.

• sacralization [sa″kr l-ľ-za′sh n] anomalous fusion of the last lumbar vertebra with the first segment of the sacrum.

• sacrectomy [sa-krek′t -me] excision or resection of the sacrum.

• sacred bamboo see Nandina domestica.

• Sacred cat of Burma see Birman.

• sacr(o)- word element. [L.] relationship to the sacrum.

• sacrocaudal pertaining to the sacrum and the tail.

  • s. agenesis, s. dysgenesis abnormal development of the vertebrae in the area; seen most commonly in Manx cats, where it is inherited as a autosomal dominant trait, and in dogs that are naturally tailless, e.g., Old English sheepdogs, British bulldogs, and others. It is often associated with abnormalities of innervation to the anus, urinary bladder, and sometimes the hindlegs and tail.
  • s. fusion an anomalous union between the sacrum and caudal vertebrae.
  • s. joint the joint between the sacrum and the tail.
  • s. luxation a relatively common traumatic injury in dogs and cats, caused by traction on the tail. Neurological deficits result from hemorrhage, edema, and avulsion of nerve roots in the terminal spinal cord. There may be urinary and fecal incontinence, posterior paresis, and paralysis of the tail.

• sacrococcygeal [sa″kro-kok-sij′e- l] pertaining to the sacrum and coccygeal vertebrae; see sacrocaudal.

• sacroiliac [sa″kro-il′e-ak] pertaining to the sacrum and the ilium, or the joint between these two bones, or to the part of the back where these bones meet on both sides of the back.

• sacroiliitis [sa″kro-il″e-i′tis] inflammation of the sacroiliac joint.

• sacrolumbar [sa″kro-lum′b r, -bahr] pertaining to the sacrum and lumbar vertebra; the loins.

• sacropelvic [sa″kro-pel′vik] pertaining to the pelvis and sacrum.

• sacrosciatic [sa″kro-si-at′ik] pertaining to the sacrum and ischium.

• sacrospinal [sa″kro-spi′n l] pertaining to the sacrum and vertebral column.

• sacrotuberous ligament [sa″kro-too′b r- s] extends from the sacrum to the ischium; prominent in the dog, absent in the cat. See Table 11.

• sacrouterine [sa″kro-u′t r-in] pertaining to the sacrum and uterus.

• sacrovertebral [sa″kro-vur′t -br l] pertaining to the sacrum and vertebrae.

• sacrum [sa′kr m] the triangular-shaped bone between the lumbar and coccygeal vertebrae; formed usually of five fused vertebrae (four in pigs, three in dogs) that are wedged between the two hip bones. See also Table 9.

• SAD rabies vaccine Street–Alabama–Dufferin strain of attenuated rabies vaccine.

  S-01.

  

  Schematic dorsal view of pelvis showing position of sacrum and short dorsal sacroiliac ligament (hatched lines) that runs from the tuber sacrale to the sacral spinous processes.

  S-02.

  

  Canine sacrum, dorsal view.

• saddle [sad′ l] 1. the back region over the thoracic vertebrae. 2. a coat color marking in dogs, usually black, located over the back. Seen in Beagles. 3. a piece of harness for either riding or draft.

  • s. thrombus see saddle thrombus, aortic embolism.
  • s. scab see equine staphylococcal dermatitis.
  • s. sore, s. gall a pressure sore caused by bad riding technique or more commonly a badly fitting or poorly stuffed saddle.

• Saddleback see Wessex saddleback.

• saddlepatch disease see columnaris disease.

• safelight a filtered light source for use in photographic darkroom when developing x-ray film; should comply with the specifications of the type of filter being used and the screen-film combination.

• safety avoidance of occupational, iatrogenic or personal injury.

  • drug s. freedom from undesirable side-effects; increases with specificity and selectivity of a drug. See also safety index (below).
  • s. index maximum tolerated dose/recommended dose, the doses being expressed in similar terms, e.g., mg/lb, mg/kg.
  • radiological s. routine the specific routine to be followed in an x-ray room to ensure minimal risk to all parties.
  • restraint s. proper use of appropriate restraint procedure when dealing with any animal.
  • s. specifications specifications laid down by a local government authority about the construction and equipment to be used in a radiological facility.

• safety pin appearance the appearance of Clostridium perfringens spores in fecal examinations; the open end represents the remains of the vegetative cell.

• Saffan a steroidal preparation containing two pregnanediones (alfaxalone and alfadolone acetate) previously used in cats for the induction of anesthesia primarily in felines. Withdrawn from the market due to severe adverse effects, likely caused by the solubilizing agent Cremophor EL, and replaced with alfaxalone as the sole component.

• safflower meal [saf′low- r] ground cake made of decorticated residue of seeds of Carthamus tinctorius, rich in linoleic acid. A modest protein dietary supplement deficient in methionine and lysine. Called also kurdee.

• sage [sāj] common name for plants in the genus Salvia.

  • poison s. Isotropisatropurpurea.
  • s. sickness unspecified poisoning by Artemisia spp.
  • Texas sageSalvia texana.

• sagebrush common name for plants in the genus Artemisia; includes big sagebrush (A. tridentata), sand sagebrush (A. filifolia) three tip sagebrush (A. tripartita).

• sagging crop see pendulous crop.

• sagging posture comprises drooping ears, head hung low, tail down (unkinked in the case of pigs), lackluster facial expression.

• sagittal [saj′ľ-t l] 1. shaped like an arrow. 2. situated in the direction of the sagittal suture; said of a plane or section parallel to the median plane of the body.

• sago palm [sa′go] Metroxylon sagu, the usual source of sago in the Pacific region; misleading common name given to the cycad Cycas revoluta, which is not a palm. See Cycas poisoning.

• sago spleen [sa′go] the white pulp (lymphoid follicular tissue) of the spleen is enlarged and protrudes from the capsular and cut surfaces like grains of sago. Occurs in amyloidosis and splenic lymphoma.

• Sahelian emanating from or pertaining to Sahel, the region south of the Sahara desert in Central Africa.

  • S. goat many varieties of this dual-purpose breed in Northwest Africa.

• Sahiwal a reddish-dun zebu type breed of dairy cattle. Usually has white markings.

• SAIDS simian acquired immune deficiency syndrome.

• sail sign the thymus, seen as a triangular structure in the left, cranial mediastinum on ventrodorsal radiographs of the thorax in young dogs.

• St. George disease see Pimelea.

• St. Hubert hound see Bloodhound.

• St. John’s wort see Hypericum.

• St. Louis encephalitis see St. Louis encephalitis.

• saki (Pithecia spp.) a small, longhaired, bushy-tailed, New World monkey. Includes the bearded sakis (Chiropotes spp.)

• sal [sal] [L.] salt.

• salamander [sal″ -man′d r] lizard-like amphibians in the order Urodela; they may be aquatic, semi-aquatic, or terrestrial, often depending on their life stage. They are capable of regenerating lost body parts, and in order to escape predators will shed their tail, which later regrows. Neoteny, the maintenance of larval characteristics throughout life, is a common phenomenon in these animals. Popular as pets, they are opportunistic predators. See also newts.

  • s. poisoning dogs and cats mouthing salamanders may become distressed with excessive salivation, muscular weakness and incoordination, and rarely convulsions.

• Sala’s cells star-shaped cells of connective tissue in the fibers that form the sensory nerve endings situated in the pericardium.

• salbutamol [sal-bu′t -mol] see albuterol.

• Salers mahogany red, dual-purpose French cattle.

• salicyl-sulfonic acid test [sal″ľ-s l-s l-fon′ik] precipitation of protein in a urine sample by a 20% aqueous solution of salicyl-sulfonic acid. Placing the urine over a layer of reagent in a test tube results in the formation of a white ring where the two solutions meet, indicating that protein is present. May be abbreviated as SSA test.

• salicylamide [sal″ľ-s l-am′īd] an amide of salicylic acid; used as an analgesic, but toxic in cats.

• salicylanilides [sal″ľ-s l-an′ľ-līd] a group of anthelmintics that exert their action by uncoupling mitochondrial reactions that are critical to electron transport and associated phosphorylation in the metabolic system of the parasite. Bind to plasma proteins and persist for several weeks. They are effective against cestodes and trematodes but generally not nematodes. Some are active against Haemonchus contortus, e.g., rafoxanide and closantel. Used in cattle, horses, dogs, cats, sheep, goats, pigs, and poultry.

• salicylate [sal″ľ-sil′āt, s -lis′ -lāt] any salt or ester of salicylic acid. The salicylates used as drugs for their analgesic, antipyretic, and antiinflammatory effects include aspirin (acetylsalicylic acid, ASA), methyl salicylate, and sodium salicylate. Low dosages of salicylates are used primarily for the relief of mild-to-moderate pain or fever. Aspirin is also used to prevent or limit the severity of ocular pain and cumulative structural damage in horses with recurrent uveitis (also known as periodic ophthalmia and ‘moon blindness’). The main mechanism of action for aspirin and other salicylates is inhibition of the branch of the arachidonic acid cascade that is mediated by cyclo-oxygenase (COX), and thus inhibition of prostaglandin, prostacyclin, and thromboxane synthesis. In addition to its anti-inflammatory and analgesic effects, aspirin prolongs the bleeding time by irreversibly inhibiting platelet activation. Salicylates may cause gastric ulceration and bleeding because they act as nonselective COX inhibitors, inhibiting the COX-1 isoenzyme that is constitutively expressed and, among other functions, participates in the maintenance of the gastric mucosal barrier. Also see aspirin poisoning.

• salicylazosulfapyridine [sal″ľ-sil-az″o-sul″f -pir′ľ-dēn] see sulfasalazine.

• salicylic acid [sal′ľ-sil′ik] o-hydroxybenzoic acid; used as a keratolytic. See also salicylate.

• salicylism [sal′ľ-sil″iz- m] toxic signs caused by salicylic acid.

• saline [sa′lēn, sa′līn] salty; of the nature of a salt.

  • hypertonic s. therapy an alternate to the expensive and timeconsuming continuous intravenous infusion of isotonic solution for treatment of endotoxic shock, hemorrhagic shock, and the rehydration of hypovolemia, particularly in farm animals. Consists of the rapid intravenous injection of hypertonic saline followed immediately by balanced polyionic fluids.
  • hypertonic s. a solution containing 1%–23.4% NaCl.

    S-03.

    

    The sagittal plane. Christenson, D.E., Veterinary Medical Terminology. Saunders, 2008.

  • s. solution a solution of salt (sodium chloride) in purified water. Physiological saline solution is a 0.9%solution of sodiumchloride andwater and is isotonic, i.e., of the same osmotic pressure as blood serum.
  • s. water poisoning see sodium chloride poisoning.
  • s. waters waters from surface running mineral springs, water obtained from natural underground storages in artesian and subartesian bores.
  • Whittingham’s s. a phosphate-buffered saline used to store fertilized embryos.
• salinomycin [sal″in-o-mi′sin] an ionophore coccidiostat and growth promotant with a broad spectrum of efficiency and closely related to monensin and lasalocid. Can cause polyneuropathy in cats.

  • s.–tiamulin poisoning effects of feeding a combination of both drugs is related to dosage and feeding methods.

• saliuresis diuresis due to high electrolyte excretion; e.g., the feeding of additional salt as a prevention against urolithiasis in sheep and cattle acts in this way. Some useful salt or osmotic diuretics may have to be administered parenterally because of poor absorption.

• saliva [s -li′v] the enzyme-containing secretion of the salivary glands.

  • s. tests tests conducted on the saliva of horses competing in races or show events to detect the presence of drugs used to affect the horse’s performance.

• salivant [sal′ľ-v nt] an agent that stimulates the flow of saliva.

• Salivaria [sal″ľ-var′e- ] the anterior station group of trypanosomes that are transmitted via the mouthparts of their intermediate hosts. Includes T. brucei, T.cruzi, T. gambiense, T. rhodesiense.

• salivarian [sal″ľ-var′e- n] said of trypanosomes, such as Duttonella, Trypanosoma, Pycnomonas, and Nannomonas. These trypanosomes are passed to the recipient host in the saliva of an insect such as the tsetse fly (Glossina spp.). See also Salivaria.

• salivary [sal′ľ-var-e] pertaining to the saliva.

  • s. amylase an α-amylase, ptyalin, initiates digestion of starch and glycogen in the mouth. Dogs, cats, and horses appear not to secrete the enzyme.
  • s. calculus sialolith. See salivary calculus.
  • s. duct atresia a congenital absence of lumen in the duct; causes distention then atrophy of the gland.
  • s. duct dilatation see ranula.
  • s. ducts excretory ducts that carry the saliva from the glands to the mouth cavity.
• salivary gland [sal′ľ-var-e] any of the glands around the mouth that secrete saliva. The major ones are the three pairs known as the parotid, mandibular or submandibular, and sublingual glands. There are other smaller salivary glands within the cheeks, e.g., zygomatic gland, and in the tongue.

  • s. g. inflammation see sialoadenitis, parotiditis.
  • s. g. squamous metaplasia of the interlobular duct of the salivary gland is a feature of hypovitaminosis A.
• salivation [sal″ľ-va′sh n] 1. the secretion of saliva. 2. ptyalism.

  • excessive s. may be caused by slaframine toxicosis from the fungus Rhizoctonia leguminocola, by foreign bodies or painful lesions in the mouth. To be distinguished from drooling of saliva because of failure to swallow.
  • s. inhibitor antisialagogue; examples are atropine and glycopyrrolate.

• salivon a functional salivary unit consisting of several acini and their related ducts and tubules.

  S-04.

  

  Salivary glands in the dog.

• salmeterol [sal-met′ r-ol] a long-acting β₂-adrenergic agonist used in inhalation therapy for relief of bronchoconstriction.

• Salmincola a genus of freshwater parasitic crustaceans that attach to the gills of salmonid fish and cause obstruction of respiration and blood loss. Severe infections may result in reduced growth rate and mortality. Includes S. edwardsi and S. californiensis.

• Salmo genus of salmon and trout in the family Salmonidae. Includes S. trutta (brown trout) and S. salar (Atlantic salmon), which is commonly used in aquaculture.

• salmon the common name for fish in the family Salmonidae; many species are in the genera Salmo and Oncorhyncus.

  • Atlantic s. Salmosalar.
  • Chinook s.Oncorhynchus tshawytscha.
  • chum s.Oncorhynchus keta.
  • coho s.Oncorhynchus kisutch.
  • pink s.Oncorhynchus gorbuscha.
  • s. poisoning, salmon disease a disease of dogs and other canids caused by eating raw salmon or other fish containing encysted metacercariae of the fluke Nanophyetus salmincola, which is the vector for Neorickettsia helminthoeca. It occurs only in the Pacific Northwest of the US. The disease in dogs is characterized by fever, enlarged lymph nodes, ocular discharge, and edema of the eyelids, followed by vomiting, then diarrhea and later severe dysentery, and death in untreated cases. See also Elokomin fluke fever.
  • sockeye s.Oncorhynchus nerka.

• Salmonella [sal″mo-nel′ ] a genus of gram-negative, nonlactose fermenting, medium-sized, rod-shaped bacteria. Members of the family Enterobacteriaceae, with most strain having flagella and pili. The genus contains seven phylogenic subgroups, allocated across two species, S. enterica and S. bongori (subgroup V), with S. enterica divided into six subspecies, enterica (subgroup I), salamae (subgroup II), arizonae (subgroup IIIa), diarizonae (subgroup IIIb), houtenae, and indica (subgroup VI). The subspecies are further divided into a very large number of serovars. Most species pathogenic for homeothermic animals are in S. enterica subsp. enterica. S. enterica subsp. salamae) and S. enterica subsp. arizonae include some species occasionally pathogenic for animals and birds. The salmonellae include the typhoid–paratyphoid bacilli and bacteria that are usually pathogenic for domestic and wild animals but that are often transmitted to humans. They cause salmonellosis, which has a number of manifestations, and some are specific causes of abortion. Although serovars are not recognized as species, the serovar names are often written as though they are species names after the species has beenmentioned once. Thus Salmonella enterica subspecies (subsp./ssp.) enterica serovar (ser.) Typhimuriumshould be used at the first mention, then subsequently Salmonella Typhimuriumor S. Typhimuriumcan be used. The serovar name should not be italicized and the first letter should be capitalized. Serovar is increasingly preferred over serotype.

  S-05.

  

  Lymph node aspirate from a dog with salmon poisoning disease. A large histiocyte contains granular coccoid organisms consistent with Neorickettsia helminthoeca.

  • S. Abortusequi causes abortion in horses. A serovar within S. enterica subsp. enterica.
  • S. Abortusovis, S. Montevideo cause abortion in sheep. A disease notifiable to the OIE (see Table 21). Serovars within S. enterica subsp. enterica.
  • S. enterica subsp. arizonae cause severe enteritis and septicemia in chicks and turkey poults.
  • S. Bovismorbificans causes enteritis in cattle and horses. A serovar within S. enterica subsp. enterica.
  • S. Choleraesuis var. Kunzendorf causes septicemic and enteric salmonellosis of swine. Called the hog cholera bacillus because of the similarity of the clinical diseases. A serovar within S. enterica subsp. enterica.
  • S. Dublin causes septicemia, meningitis, enteritis, and abortion in cattle and abortion in sheep. A serovar within S. enterica subsp. enterica.
  • S. Enteriditis a common cause of gastroenteritis in humans. Recorded also in most domestic mammalian species and fowl. A serovar within S. enterica subsp. enterica.
  • S. Gallinarum causes fowl typhoid. A serovar within S. enterica subsp. enterica.
  • S. Heidelberg an occasional isolate in horses. A serovar within S. enterica subsp. enterica.
  • S. Pullorum causes pullorum disease in chickens.
  • standard S. Pullorum strains contains only small amounts of the 12₂ antigen relative to the O 12₃ antigen. In variant strains, the reverse is the case. Polyvalent antigen is thus preferable for serological testing.
  • S. Typhimurium A serovar within S. enterica subsp. enterica. Causes outbreaks of enteritis in most species, often related to rodent infestation. The cause of fowl paratyphoid. Clinical disease is commonly manifest with severe diarrhea and dehydration, but sub-clinical infection and intestinal carriage is common, particularly in swine and poultry, where contaminated food products are a public health risk. Clonal epidemic strains can arise to produce disease in both domestic and wild animals and humans, as occurred with DT104 in the 1990s and early 2000s. One cause of nosocomial infections in horses in veterinary school hospitals. The causative agent of mouse typhoid, fowl paratyphoid, and food-borne enteric infections in humans. Intestinal carriage is common in pet reptiles.
  • S. Typhisuis an uncommon isolate in pigs. A serovar within S. enterica subsp. enterica.

• salmonellosis [sal″mo-n l-o′sis] a highly contagious disease of all animal species caused by Salmonella. Salmonella serovars differ in the range of hosts they can infect and in the nature of disease that may result. Some can infect a wide range of hosts and are termed ubiquitous; others are very restricted in their host range, causing severe disease in only one host. Depending on the serovar and host, salmonellosis may be manifest by septicemia and acute or chronic enteritis. Abortion is a common accompaniment, particularly in food animals and horses. Localization may occur in almost any organ. It is a rare occurrence in companion animals. Called also paratyphoid. Certain serovars are transmissible to humans, and salmonellosis is an important zoonosis, with special implications for veterinarians involved in food hygiene.

• salmonid a member of the fish family Salmonidae. Includes salmon, trout, char.

• salpingectomy [sal″pin-jek′t -me] excision of a uterine tube.

• salpingemphraxis [sal″pin-j m-frak′sis] obstruction of a pharyngotympanic (eustachian) tube.

  S-06.

  

  Red discoloration of ears and snout with septicemic salmonellosis.

  S-07.

  

  Avian salpingitis as a result of Salmonella infection.

• salpingitis [sal″pin-ji′tis] 1. inflammation of the oviduct (uterine tube). 2. inflammation of a pharyngotympanic (eustachian) tube.

  • mural s. pachysalpingitis.
  • parenchymatous s. pachysalpingitis.

• salping(o)- word element. [Gr.] relationship to a tube (eustachian tube or uterine tube).

• salpingocele [sal-ping′go-sēl] hernial protrusion of a uterine tube.

• salpingocyesis development of the embryo within a uterine tube; tubal pregnancy.

• salpingography [sal″ping-gog′r -fe] imaging of the uterine tubes after intrauterine injection of a contrast medium.

• salpingolithiasis the presence of calcareous deposits in the wall of the uterine tubes.

• salpingolysis [sal″ping-gol′ľ-sis] surgical separation of adhesions involving the uterine tubes.

• salpingo-oophorectomy [sal-ping″go-o-of″ -rek′t -me] excision of a uterine tube and ovary.

• salpingo-oophoritis [sal-ping″go-o-of″ -ri′tis] inflammation of a uterine tube and ovary.

• salpingo-oophorocele [sal-ping″go-o-of′ -ro-sēl] hernia of a uterine tube and ovary.

• salpingopexy [sal-ping′go-pek″se] fixation of a uterine tube.

• salpingopharyngeal [sal-ping″go-f -rin′je- l] pertaining to the auditory tube and the pharynx.

• salpingoplasty [sal-ping′go-plas″te] plastic repair of a uterine tube.

• salpingostomy [sal″ping-gos′t -me] 1. formation of an opening or fistula into a uterine tube for the purpose of drainage. 2. surgical restoration of the patency of a uterine tube.

• salpingotomy [sal″ping-got′ -me] surgical incision of a uterine tube.

• salpinx [sal′pinks] a tube such as a uterine tube (oviduct) or an auditory tube.

• Salsola plant genus in the family Chenopodiaceae; contains soluble oxalates and causes oxalate poisoning characterized by nephrosis, urolithiasis; includes S. barbata, S. australia (S. kali tumbleweed, soft roly-poly, Russian thistle).

  • S. tuberculatiformis, S. tuberculata var. tomentosa poisoning of sheep with this South African plant causes prolongation of gestation, enlargement of the fetus, and dystocia. Syndrome called grootlamsiekte. Called also S. tuberculata var. tomentosa.

• SALT see skin-associated lymphoid tissues.

• salt [sawlt] 1. any compound of a base and an acid. 2. salts, a saline purgative. See also sodium chloride.

  • s. brine strong solution of common salt (sodium chloride) used to pickle meat and other human foods. Sodium chloride is the biggest component, but large quantities of nitrate are usually present and represent a greater toxicity hazard than does the salt.
  • buffer s. a salt in the blood that is able to absorb slight excesses of acid or alkali with little or no change in the hydrogen ion concentration.
  • common s. sodium chloride.
  • s. gland a salt excreting gland of seabirds, some reptiles such as sea snakes, some crocodiles, marine iguanas, and some fish that enables the drinking of sea-water. The gland ducts discharge in various places depending on the species, such as the nose, conjunctival sac, or tongue.
  • iodized s. supplementing salt with iodine is done in many locations around the world where the normal diet is deficient in order to prevent the occurrence of iodine deficiency; see also salt lick (below).
  • s. hunger common in circumstances in which animals are derived of any salt; manifested by leather chewing, earth eating, coat licking, and urine drinking.
  • s. lick 1. naturally occurring deposit of salt in the form of a shallow pan that wild and domestic animals consume by licking. 2. in livestock production, a prepared mixture of salt, with or without other minerals, the composition varying with the local nutritional deficiency. The cattle or sheep are encouraged to lick by the taste of the salt and serendipitously acquire the other minerals. May be loose and put out in containers covered against the weather or formed into blocks that resist rain erosion and are fitted into holders fixed to buildings or free-standing in the pasture. See also mineral–salt mixture.
  • s. poisoning see sodium chloride poisoning
  • Rochelle s. potassium sodium tartrate, used as a cathartic.
  • s. sick see copper nutritional deficiency.
  • smelling s’s aromatic ammonium carbonate, a stimulant and restorative.
  • s. tolerant capable of surviving in a high concentration of salt, e.g., some bacteria, including staphylococci.

• salt-losing crisis vomiting, dehydration, hypotension, and sudden death due to very large sodium losses from the body.

• salt sickness dual copper and cobalt deficiency.

• salt-stored ovum penetration assay a test of the ability of spermatozoa in a semen sample to attach to and penetrate the zona pellucida of ova. Salt storage in NH₄SO₄ enables eggs from abattoir-collected ovaries to be used for several months.

• saltation [sal-ta′sh n] 1. the action of leaping, as in louping ill or the dancing of porcine myotonia congenita. 2. conduction along myelinated nerves. 3. in genetics, an abrupt variation in species; a mutation.

• saltatory [sal′t -tor″e] pertaining to or emanating from saltation.

  • s. conduction the leaping action transfer of electric potential from node of Ranvier to node of Ranvier along a medullated nerve fiber instead of a steady flow along the length of the nerve.
• saltbush a widespread forage or browse plant on extensive range in Australian arid zones. Called also Atriplex spp. Strictly a maintenance feed.

  • annual s.Atriplex muelleri.
  • barrier s. see Enchylaena tomentosa.
  • four wing s.Atriplex canescens.
  • ruby s. see Enchylaena tomentosa.

• salted meats meats cured for preservation by the addition of salt to the external surface. The salt draws out water by osmosis. Plain salting is not a very sophisticated procedure, and most commercial curing has at least nitrate in the curing mixture. See also bacon curing.

• Salter-Harris classification [sawl′t r] a system for classifying fractures, fracture-separations, and separations of the physis into five types. Salter type I—a separation of the epiphyseal plate; Salter type II—a partial separation of the epiphyseal plate and fracture into the metaphyseal bone; Salter type III—a partial separation of the epiphyseal plate and a fracture through the epiphysis; Salter type IV—a fracture through the metaphysis, across the epiphyseal plate, and through the epiphysis; Salter type V—a crushing or compression injury to the epiphyseal plate.

  S-08.

  

  Salter-Harris classification of physeal fractures based on the radiographic location of the fracture line.

• salting [sawl′ting] (of cattle) a term used in the US where placement site of salt on a range area is moved so as to attract cattle to the new placement area; also used to move cattle from mountain grazing in the Fall.

• salting out [sawl′ting out] the separation of protein fractions in the serum or plasma by precipitation using increasing concentrations of neutral salts.

• saltpeter, saltpetre potassium nitrate.

• salubrious [s -loo′bre- s] conducive to health; wholesome.

• Saluki a medium-sized, very graceful dog with a fine, silky coat in a range of colors, that is flat on the body, but forms slight ‘feathers’ on the legs, ears, tail, and sometimes thighs and shoulders. There is also a smooth variety, without feathering. A sight-hunting desert dog, believed to be the oldest known breed of domesticated dog. Called also Gazelle hound, Persian greyhound.

• saluresis [sal″u-re′sis] excretion of sodium and chloride in the urine.

• saluretic [sal″u-ret′ik] 1. pertaining to saluresis. 2. an agent that promotes saluresis.

• salutary [sal′u-tar″e] healthful.

• salvage pathways energy-saving reutilization of preformed constituents, often purine and pyrimidine compounds that would otherwise be lost to degradation.

• salvage statistics [sal′v j] see salvage statistics.

• Salvation Jane Echiumplantagineum.

• salve [sav] ointment.

• Salvelinus genus of farmed finfish in family Salmonidae. Includes S. fontinalis (brook trout, splake), S. namaycush (splake, lake trout).

• Salvia [sal′ve- ] a genus of the plant family Lamiaceae.

  • S. coccinea an unidentified toxin causes abortion, diarrhea, recumbency. Called also S. lineata, red salvia, blood sage.
  • S. reflexa has a high nitrate content and causes nitrate–nitrite poisoning in ruminants. Called also lanceleaf sage, mintweed.

• samarium (Sm) [s -mar′e- m] a chemical element, atomic number 62, atomic weight 150.35.

• sambar (Rusa unicolor) a large deer, native to South and Southeast Asia, Southern China, and India, and introduced in the US, Australia, and New Zealand. They are a dark color with white underside and have antlers of three or four tines.

• Sambucus [sam-boo′kus] coarse bushes, members of the family Sambucaceae; contains toxic oil that causes diarrhea; sometimes also causes cyanide poisoning. Includes S. nigra (American black elderberry, blue elderberry), S. ebulus (danewort, dwarf elderberry). Called also elder.

• SAMeS-adenosyl-_L-methionine.

• samore trypanosomiasis; called also nagana.

• Samoyed a medium-sized dog characterized by a very thick, straight, white or cream-colored coat that stands out from the body, with brown eyes and black-rimmed eyelids and lip margins. It is said to have a ‘smiling expression’. The ears are erect and the tail, with profuse haircoat, is curled over the back. The breed is predisposed to hemophilia, congenital heart defects, and familial renal disease.

• sample [sam′p l] 1. a specimen of fluid, blood, or tissue collected for analysis on the assumption that it represents the composition of the whole. 2. for statistical purposes a small collection of individual units taken from the population that is under investigation on the assumption that they represent the characteristics of the entire population.

  S-09.

  

  Samoyed.

  • EPSEM s. acronym for ‘equal opportunity of selection method’.
  • grab s. sample of greasy wool taken at random by a special machine from each bale on the sale floor. Buyers price the bale on the basis of the appearance of the grab sample and the objective measurements.
  • multi-stage random s. with very large populations, it may be desirable to arrange the data into groups on one criterion, e.g., address by area of postcode, and to select randomly from within this group, then select from within this sample to obtain randomly a representative number of specimens, such as dogs of each age group.
  • random s. the selection from a population of the units that are to constitute the sample of that population is made in such a way that each unit of the population has an equal chance of being selected. Called also simple random sample.
  • simple random s. see random sample (above).
  • stratified random s. the data are arranged into subsets or strata based on the possession of certain characteristics that are common to the members of the subset. The selection of units to comprise the sample of the parent population is arranged so that the proportional representation of each subset in the final sample fits a prearranged schedule.
  • volunteer s. sample donated by interested parties; a biased sample because it does not represent all sections of the population. Called also self-selection.
• sampling [sam′pling] the process of selecting a sample.

  • area s. dividing the population into equal areas and randomly selecting from among the areas.
  • cluster s. when the population to be sampled exists in clusters, e.g., herds, sampling can be done by random selection between the herds. This assumes that each cluster is a homogeneous group.
  • s. fraction ratio of the number of units in the population to the number of units in the population.
  • s. frame the names of the component parts of the population from which the sample is to be collected.
  • quota s. the sections of the population, e.g., milking cows, dry cows, yearlings, calves are represented in the sample in the same proportion as they exist in the population.
  • stratified s. a simple random selection is performed in each stratum of those created in order to permit a different sampling percentage to be used in each stratum.
  • systematic s. the sampling is random but the samples are drawn systematically, say every third unit, the first unit also being chosen randomly.
  • two-stage s. an example of multi-stage sampling. The first sampling is of large groups, e.g., herds, then a second-stage sampling is carried out within herds, e.g., sire families, with possibly a third stage, of individual cows within the sire families.
  • s. units individual members of a population. It is often difficult to define exactly what is a unit because of the design of the study.
  • s. variation the variation that occurs between samples of the one population. A measure of the random error of the sampling technique used.

• San Clemente goat small, multicolored goat left by Spanish on San Clemente island off California. Endangered species.

• San Joaquin Valley fever the primary form of coccidioidomycosis.

• San Miguel sea lion virus disease a disease of sea lions, caused by a calicivirus, genus Vesivirus, that is transmissible to swine in which it causes a disease indistinguishable from vesicular exanthema of swine. Vesicular lesions of the skin and mucosae, abortion, pneumonia, and encephalitis are associated with the infection in sea lions. Related viruses have been recovered from other pinniped species.

• sanative [san′ -tiv] curative; healing. Said of trypanocidal drugs used between long courses of more popular drugs in order to avoid the development of resistance to those drugs by the trypanosomes.

• sanatory [san′ -tor″e] conducive to health, curative, health-giving.

• Sancassania berlessei a mite of stored products occasionally infests sheep.

• sand [sand] 1. material occurring in fine, gritty particles loose in the body. 2. geological sand is ingested by animals, especially horses, grazing on very sandy soil. The animals may take in large amounts, and this accumulates in the large sacs of the alimentary tract, the reticulum of the cow, and the cecum and colon in horses. Sand or dust storms, or volcanic dust fallout may produce a similar, acute situation.

  • s. colic see sand colic.
  • s. enteritis acute sand ingestion may cause enteritis with severe, sometimes fatal diarrhea. See also enteritis.
  • s. rash, s. burn irritation and weeping of the toe webbing in racing Greyhounds causing lameness. Caused usually by racing in sand.
  • s. toe Greyhounds racing in sand suffer impaction of sand under the coronary band, causing lameness, mostly in the inner and outer toes of the hind paws.
  • uterine s. see uterine sand.

• sand twin leaf Zygophyllumammophilum.

• sandbags small sacks containing sand used to support an anesthetized animal in dorsal recumbency and prevent it from rolling sideways during anesthesia or surgery.

• sandbath, sand roll a stall covered with deep sand used for horses to roll in after exercise.

• sandcrack [sand′krak] vertical cracks in the hoof that commence at the coronet and run parallel to the horn tubules and toward the toe. Are serious defects because they indicate an injury to the coronet and a possible extension to the sole.

• sandfly [sand′fli] a common name, initially applied to Phlebotomus spp. in the Old World, is also applied to biting midges of the genera Culicoides, Simulium and Austrosimulium spp. in Australia. Called also owl midges.

• Sander a genus of fish in the family Percidae, commonly called pike-perch.

• Sandhoff’s disease [zahnd′hof] see GM₂ gangliosidosis.

• sandplain woody pear Xylomelumangustifolium.

• sandwort see Arenaria serpyllifolia.

• Sanfilippo’s III-D syndrome [san-fľ-lip′o] a human disease similar to Nacetyl-glucosamine-6-sulfatase deficiency in Nubian goats.

• Sanga a type of draft cattle with a small cervicothoracic hump and long horns, originating in eastern and southern Africa. It includes many varieties.

• Sanga Nguni cattle a breed of Bos indicus cattle in which testicular hypoplasia is recognized as being inherited.

• Sanger–Coulson method a method of sequencing DNA; called also dideoxy or chain termination method. It involves the use of 2′3′ dideoxynucleoside triphosphates (dd NTPs) that lack a 3′-hydroxyl group.

• sangui- word element. [L.] relationship to blood.

• sanguifacient [sang″gwi-fa′sh nt] forming blood.

• sanguinarine [sang″gwľ-na′rēn] one of the isoquinoline alkaloids found in Chelidonium majusand Argemone spp.

• sanguine [sang′gwin] abounding in blood.

• sanguineous [sang-gwin′e- s] bloody; abounding in blood.

• Sanguinicola a genus of the family Aporocotylidae containing about 24 species of digenetic flukes found in the vascular system of freshwater and marine fish.

  • S. inermis, S. klamanthensis found in cyprinid and salmonid fish in which it is a serious pathogen, especially in cultured carp and trout. The gills and kidneys are affected most and mortality may be high.

    S-10.

    

    Sandcrack.

• sanguinolent [sang-gwin′ -l nt] of a bloody tinge.

• sanguinopurulent [sang″gwľ-no-pu′roo-l nt] containing both blood and pus.

• sanguis [sang′gwis] [L.] blood.

• sanguivorous [sang-gwiv′ -r s] blood-eating; said of female mosquitoes that prefer blood to other nutrients.

• Sanhe named after Mongolian district.

  • S. cattle Chinese meat and draft cattle, red and white or black and white; originated from local breeds plus Simmental or Friesian.
  • S. horse riding and draft light horse, all coat colors.

• sanies [sa′ne-ēz] a fetid ichorous discharge containing serum, pus and blood.

• sanitarian [san″ľ-tar′e- n] one skilled in sanitation and public health science.

• sanitary [san′ľ-tar″e] promoting or pertaining to health.

  • s. trap container located between the air system and the milk system in a milking machine designed to trap fluids that would otherwise pass from one to the other.

• sanitation [san″ľ-ta′sh n] the establishment of conditions favorable to health, especially with respect to infectious diseases. Includes disposal of infective materials, especially carcasses, discharges and excrement, application of disinfectants and general cleaning to make disinfection effective, isolation of infective animals and improvement in ventilation of buildings, improving feeding, and watering arrangements to avoid fecal and urinary contamination of food and water.

• sanitization [san″ľ-tľ-za′sh n] the process of making or the quality of being made sanitary, or sterile.

• sanitize [san′ľ-tīz] to clean and make hygienic by removing most harmful microorganisms from a surface.

• sanitizer a sanitizing product capable of cleaning and disinfecting; usually a formulation containing a disinfectant and a detergent.

• Santa Gertrudis a red, tropical beef breed, originated on the King ranch in Texas by crossbreeding Shorthorn and Brahman cattle. The breed shows a relatively high degree of both heat and tick resistance.

• Santorini’s duct, duct of Santorini [sahn″to-re′ne] see accessory pancreatic duct.

• Sao₂ symbol for percentage of available hemoglobin that is saturated with oxygen. See blood gas analysis.

• SAP serum alkaline phosphatase.

• saperconazole a triazole antifungal agent.

• saphena [s -fe′n] the small saphenous or the great saphenous vein.

• saphenous [s -fe′n s] pertaining to or associated with a saphenous vein; applied to certain arteries, nerves, etc. See also Tables 8, 13, and 14.

• Sapium sebiferum member of plant family Euphorbiaceae; contains an unidentified toxin that causes nephrosis and diarrhea. Called also Stillingia sebifera, Triadica sebifera, Chinese tallow tree, Chinese tallow wood.

• sapo [sa′po] [L.] soap; a compound of fatty acids with an alkali.

• saponaceous [sa″po-na′sh s] soapy; of soap-like feel or quality.

• Saponaria [sa″po-nar′e- ] genus of the plant family Caryophyllaceae; contain toxic saponins that cause diarrhea. Includes S. officinalis, S. vaccaria. Called also cow cockle, soapwort, hedge pink, bouncing bet.

• saponifiable [s -pon″ľ-fi′-b l] capable of being made into soap.

• saponification [s -pon″ľ-fľ-ka′sh n] conversion of an oil or fat into a soap by combination with an alkali. In chemistry, the term now denotes the hydrolysis of an ester by an alkali, resulting in the production of a free alcohol and an alkali salt of the ester acid.

• saponin [sap′o-nin] a group of glycosides widely distributed in the plant world and characterized by (1) their property of forming durable foam when their watery solutions are shaken; this property may have importance in some plants in the development of frothy bloat in ruminants; (2) their ability to lyse erythrocytes even in high dilutions; and (3) their having the compound sapogenin as their aglycones.

  • lithogenic s’s saponins in panicoid grasses (Panicum, Brachiaria), Agave lecheguilla, Narthecium ossifragum, Tribulus terrestris are probably responsible for causing crystal-associated cholangiohepatopathy and subsequent secondary photosensitization; this is suspected as the cause of photosensitization associated with other plants. Called also steroidal saponin.
  • steroidal s. see lithogenic saponins (above).

• sapophore [sap′o-for] the group of atoms in the molecule of a compound that gives the substance its characteristic taste.

• sapremia septicemia caused by a saprophytic organism.

• sapr(o)- word element. [Gr.] rotten, putrid, decay, decayed material.

• saprocyclozoonoses a disease with features of both the saprozoonosis and cyclozoonosis, e.g., tick paralysis.

• Saprolegnia parasitica [sap″ro-leg′ne- ] causes saprolegniosis on various fish species, amphibians, and crustaceans. Produce white/gray, cottontype growths on the skin of animals, and in some cases can also affect internal organs A major problem in the fish farming industry in Europe, Chile, Canada, and Asia.

• saprolegniasis disease affecting fish eggs and juvenile fish in hatcheries worldwide; associated with infection with the oomycete Saprolegnia parasitica with growth of filamentous mycelium on the body or fins of the fish and associated tissue damage leading to death.

• saprophagous feeding on dead or decaying organic matter.

• saprophyte [sap′ro-fīt] any organism, such as a bacterium, capable of living in inanimate media, but usually used to describe microorganisms that normally live freely in the environment.

• saprophytic [sap″ro-fit′ik] pertaining to saprophyte.

• saprozoic [sap″ro-zo′ik] living on decayed organic matter; said of animals, especially protozoa.

• saprozoonosis [sap″ro-zo-on′ -sis] diseases transmissible from an abiotic environment, such as soil, water, decaying plants, or animal corpses.

• sarafloxacin a fluoroquinolone antibiotic; withdrawn from use.

• saralasin [s r-al′ -sin] a competitive angiotensin II antagonist.

• Sarcina [sahr′sľ-n ] bacteria now classified within the genus Clostridium.

  • S.-like bacteria are observed in the abomasal wall and contents of a high proportion of milk-fed lambs, kids, and calves that have died with abomasitis and abomasal bloat.

• sarc(o)- word element. [Gr.] relationship to flesh.

• sarcoarthrosis [sahr′ko-ahr-thro′sis] a joint without bone to bone contact, e.g., between scapula and thorax in quadrupeds. Called also fleshy joint, synsarcosis.

• Sarcobatus vermiculatus North American member of the plant family Polygonaceae; contains soluble oxalates that can cause oxalate poisoning. Called also greasewood.

• sarcoblast [sahr′ko-blast] a primitive cell that develops into a muscle cell. Called also myoblast.

• sarcocele [sahr′ko-sēl] any fleshy swelling or tumor of the testis.

• sarcocyst [sahr′ko-sist] any member of, or any cyst formed by Sarcocystis spp.

• Sarcocystis [sahr″ko-sis-to′sis] a genus of parasitic protozoa in the family Sarcocystidae (phylum Apicomplexa). The definitive hosts are domestic and wild carnivores with replication of the parasite in the intestinal epithelium, in which they appear as a form of coccidiosis. Mammals, birds, and reptiles act as intermediate hosts (depending on the species), with initial replication in the endothelium followed by the development of sarcocycts in the musculature or other tissues. Can be part of any prey-predator system, e.g., snake-rat, owl-mice, etc. The effects of their intermediate stages are manifested as the disease sarcocystosis.

  • S. arieticanis has a dog-sheep cycle.
  • S. bertrami has a dog-horse cycle and produces cysts in muscles but without clinical disease.
  • S. cervi cysts found in deer.
  • S. cruzi has a dog (and other feral canids)-cattle cycle; causes fever, anorexia, anemia, and weight loss in cattle but the microscopic cysts found in dogs are not pathogenic. See also sarcocystosis.
  • S. cuniculi cysts found in wild and domesticated rabbits but without apparent pathogenicity in rabbits. It has a cat-rabbit cycle, and the macroscopic cysts in cats are pathogenic.
  • S. fayeri has a dog-horse cycle but appears not to be pathogenic to the horse.
  • S. fusiformis has a cat-buffalo cycle but appears not to be pathogenic in the water buffalo.
  • S. gigantea has a cat-sheep cycle; the cysts in sheep are very large and visible with the naked eye but are not pathogenic.
  • S. hemionilatrantis has dog or coyote-mule deer cycle, and the disease in young deer may be fatal.
  • S. hirsuta (syn. S. bovifelis) has a cat-cattle cycle and is not pathogenic in cattle.
  • S. hominis has a human-cattle cycle, the enteric infection in humans causing diarrhea, and the cysts in the muscles of cattle having no observable effect.
  • S. kortei the definitive host is unknown, the intermediate host is the rhesus monkey, but the cysts in its muscles appear to cause no disability.
  • S. levinei has a dog-buffalo cycle but causes no illness.
  • S. lindemanni humans are the intermediate host but the final host is unknown.
  • S. medusiformis has a cat-sheep cycle.
  • S. miescheriana has a dog (raccoon, wolf)-pig cycle but no known pathogenicity.
  • S. moulei has a cat-goat cycle.
  • S. muris has a cat-mouse, rat, vole, etc., cycle, but the cysts are not pathogenic.
  • S. nesbitti rhesus monkeys are the intermediate hosts, but the muscle cysts are clinically silent. The final host has not been identified.
  • S. neurona causes equine protozoal myeloencephalitis.
  • S. orientalis goats are the intermediate host but are unaffected. Dogs are probably the final host.
  • S. rileyi cysts occur in the muscles of many species of domestic and wild birds without appearing to cause any ill effects.
  • S. tenella has a dog (coyote, fox)-sheep cycle and causes mortality in lambs if the infection is a heavy one.

• sarcocystosis [sahr″ko-sis-to′sis] a common infection in many food animal species caused by the intermediate stage of the protozoan parasite Sarcocystis spp. The sporocyst stages are passed in the feces of a dog or cat or other carnivore species. In the intermediate host, usually a herbivore, primary multiplication occurs in endothelial cells, with the subsequent formation of cysts in the musculature. Clinically the disease is manifested by emaciation, lameness, hypersalivation, loss of tail switch, anemia, and abortion. Subclinical infections with the intermediate stage of cysts in muscles are common in many species. The common sites are the esophageal, cardiac, and lingual muscles. Infected horses may develop equine protozoal myeloencephalitis. Abnormally, there are localizations in brain, uterus, and lungs. Called also rat-tail syndrome, Dalmeny disease. See also sarcosporidiosis.

• sarcode homeopathic remedies prepared from healthy organ tissue. See also nosode, glandular therapy.

• Sarcodina [sahr″ko-di′n ] a group of Protozoa in the phylum Sarcomastigophora, including all the amebae, both free-living and parasitic, characterized by the ability to produce pseudopodia during most of the life cycle; flagella, when present, develop only during the early stages.

• sarcoid [sahr′koid] 1. tuberculoid; characterized by noncaseating epithelioid cell tubercles. 2. pertaining to or resembling sarcoidosis. 3. sarcoidosis. See also equine sarcoid.

• sarcoidal pertaining to or of the nature of sarcoid.

  • s. granulomatous disease a sterile, sarcoidal granulomatous dermatitis in dogs characterized by multiple cutaneous plaques, nodules, or papules, nonpruritic, not painful, mostly on the neck and trunk.

• sarcoidosis [sahr″koi-do′sis] a rare, multisystemic, noncaseating, granulomatous, and lymphoplasmacytic disease of horses characterized by scaly, crusting dermatitis with alopecia extending to a generalized exfoliative dermatitis, followed by wasting, anorexia, and exercise intolerance.

• sarcolemma [sahr″ko-lem′ ] the delicate plasma membrane covering every striated muscle fiber.

• Sarcolobus globosus a plant of Asian origin in the family Asclepiadaceae. Its fruits are recorded as causing incoordination, tremor, paralysis, and death in a cat. Called also banok, kundur laut, pitis pitis.

• sarcoma [sahr-ko′m ] a malignant neoplasm derived from cells derived from mesenchymal tissue such as connective tissue, bone, cartilage, muscle, vascular, or lymphoid tissue. These malignancies metastasize more often via the blood than do carcinomas. The different types of sarcomas are named after the specific tissue they arise from: fibrosarcoma—fibrous connective tissue; lymphosarcoma—lymphocytes; osteosarcoma—bone; chondrosarcoma—cartilage; rhabdomyosarcoma—striated muscle; liposar coma—adipose cells.

  S-11.

  

  Esophageal muscle with thick-walled sarcocyst of Sarcocystis hirsute.

  • feline posttraumatic s. malignant intraocular neoplasm seen in cats within months to years following a penetrating injury to the eye, especially with lens capsule rupture. Frequently invades local structures in the orbit or brain.
  • feline vaccine-associated s. a rare malignancy in cats occurring in sites typically used for the injection of vaccines. They are rapidly growing, highly invasive sarcomas most common under the cervical-interscapular region or thigh skin. Treatment by surgical resection, radiation therapy, and/or chemotherapy may not be successful. A causal relationship with rabies and feline leukemia virus vaccines has been found. Called also feline injection site sarcoma, as some cases are associated with injection of long-acting medications other than vaccines.
  • infectious s. see canine transmissible venereal tumor.
  • mast cell s. see mast cell tumor.
  • osteogenic s. see osteosarcoma.
  • posttraumatic s. see feline posttraumatic sarcoma (above).
  • reticulum cell s. an old term for a form of malignant lymphoma, histiocytic lymphosarcoma, in which the dominant cell type is thought to be derived from histiocytic or macrophage origin. There is increasing evidence, however, that this neoplasm arises from transformed lymphocytes or immunoblasts.
  • Rous s. see Rous sarcoma.
  • soft-tissue s. collective term for the group of pleiomorphic spindle-cell sarcomas whose morphology varies fromneurofibromatous to hemangiosarcomatous to undifferentiated spindle-cell sarcoma, sometimes all in the one growth. They are routinely graded on histological features for prognostic purposes.
  • spindle-cell s. soft-tissue sarcoma (above).
  • Sticker’s s. see canine transmissible venereal tumor.
  • transmissible venereal s. see canine transmissible venereal tumor.
  • s. virus see feline sarcoma virus.

• Sarcomastigophora [sahr″ko-mas″tľ-gof′ -r] a phylum in the kingdom Protista; includes the two main subphyla Mastigophora and Sarcodina.

• sarcomatoid resembling a sarcoma.

• sarcomatosis [sahr″ko-m -to′sis] a condition characterized by development of many sarcomas.

• sarcomatous [sahr-ko′m -t s] pertaining to or of the nature of a sarcoma.

• sarcomere [sahr′ko-mēr] the contractile unit of a myofibril; sarcomeres are repeating units, delimited by the Z bands along the length of the myofibril. See also A band.

• sarcomphalocele a fleshy tumor of the umbilicus.

• Sarcophaga [sahr-kof′ -g] a genus of flesh flies in the family Sarcophagidae that deposit their larvae in wounds or sores.

  • S. carnaria, S. dux, S. fuscicauda, S. haemorrhoidalis the only clinical difference between these species appears to be their geographical distribution.

• sarcophagid pertaining to Sarcophaga spp.

• sarcoplasm [sahr′ko-plaz″ m] the cytoplasm of a myocyte.

• sarcoplasmic [sahr″ko-plaz′mik] pertaining to or emanating from sarcoplasm.

  S-12.

  

  A large feline injection site-associated sarcoma.

  S-13.

  

  Organization of proteins in a sarcomere.

  • s. organelles include a number of organelles associated with sarcoplasm.

• sarcoplast [sahr′ko-plast] an interstitial cell of a muscle, itself capable of being transformed into a muscle.

• sarcopoietic [sahr″ko-poi-et′ik] forming muscle.

• Sarcopterinus a genus of mites in the family Myobiidae.

  • S. nidulans found in the feather follicles of pigeons and other birds.
  • S. pilirostris found in the skin on the head of the sparrow.

• Sarcoptes [sahr-kop′tēz] a widely distributed genus of mites in the family Sarcoptidae that causes sarcoptic mange. Their nomenclature is confused but the most widely used system of nomenclature is S. scabiei var. canis, var. suis, var. equi, var. ovis, var. bovis, etc.

• sarcoptic mange [sahr-kop′tik] an intensely pruritic dermatitis caused by the acarid mite Sarcoptes scabiei. Although there is some species specificity with subspecies of the mite this is not complete. An almost universal infestation in pig herds except those derived by Specific Pathogen–Free techniques or those where infestation has been controlled with avermectins. A problem in many pig herds kept under organic label requirements. Lesions commence as erythema and small red papules. Extensive self-trauma leads to loss of hair and secondary infection. In long-standing cases, debilitation is also common. The lesions are usually widespread but are most easily seen on the abdominal skin and inside the thighs. In dogs, the elbows, hocks, and pinnae are most commonly affected. Besides the common infections in domestic species the disease occurs frequently in captive and freeliving primates, monkeys, rodents, canids, and ungulates. In ferrets, the lesions may be generalized, as in other species, or predominantly on the feet; commonly called footrot. Called also fox mange. See also scabies.

  S-14.

  

  Sarcoptes scabiei var. canis.

  S-15.

  

  Early sarcoptic mange in a piglet.

• sarcosis [sahr-ko′sis] abnormal increase of flesh.

• Sarcosporidia [sahr″ko-spor-id′e- ] see Sarcocystis.

• sarcosporidiasis [sahr″ko-spor″ľ-di′ -sis] see sarcocystosis.

• sarcosporidiosis [sahr″ko-spor-id″e-o′sis] the condition observed at meat inspection in which lesions caused by Sarcocystis spp. are observed. See also sarcocystosis.

• Sarcostemma a South African and Australian genus of the plant family Asclepiadaceae; contain glycosides (sarcovimisides) that cause incoordination, tremor, recumbency, and convulsions in sheep. Includes S. australe, S. brevipedicellatum, S. viminale. Called also, caustic vine, caustic creeper, or caustic bush.

• sarcostosis ossification of fleshy tissue.

• sarcotubules [sahr″ko-too′būlz] the membrane-limited structures of the sarcoplasm, forming a canalicular network around each myofibril.

• sarcous [sahr′k s] pertaining to flesh or muscle tissue.

• SARD sudden acquired retinal degeneration.

• sarmazenil a partial antagonist of benzodiazepine receptors; used in animals to reverse the effects of benzodiazepines and enable a rapid recovery from sedation with diazepam or related drugs.

• Sarot needle holder long-handled, standard type needle holder with diamond-shaped grooving on blade faces.

  S-16.

  

  Sarcoptic mange in a dog.

  S-17.

  

  Sarcoptic mange (footrot) in a ferret.

• SARS 1. severe acute respiratory syndrome caused by coronavirus ‘jumping species’ from animals to humans.

• Sartwellia flaveriae North American plant in the Asteraceae family; contains an unidentified toxin that causes nephrosis, liver damage, ascites, hydrothorax.

• SAS subaortic stenosis.

• Saskatoon serviceberry see Amelanchier alnifolia.

• SAT serum agglutination test.

• sat. saturated.

• satellite [sat′ -līt] 1. in genetics, a knob of chromatin connected by a stalk to the short arm of certain chromosomes. 2. a minor, or attendant, lesion situated near a large one. 3. a vein that closely accompanies an artery. 4. exhibiting satellitism.

  • s. cell cells present in nervous and muscle tissue, whose numbers diminish with age, which are involved in repair when damage occurs. They are capable of migration, reorientation, can proliferate, form myoblasts and myotubes, and form long cytoplasmic tails that act as tethers when they migrate.
  • s. DNA see deoxyribonucleic acid.

• satellitism [sat′ -li-tiz- m] the phenomenon in which certain bacterial species grow much better in the immediate vicinity of colonies of other unrelated species, owing to the production of an essential nutrient or cofactor by the latter species.

• satellitosis [sat″ -li-to′sis] accumulation of neuroglial cells about neurons; seen when neurons are damaged.

• satiation full satisfaction of desire to eat and drink.

• satiety [s -ti′ -te] being in a state of satiation; in experimental animals used with reference to eating and drinking.

  • s. center located in the ventromedial hypothalamic nucleus. Lesions may cause hyperphagia with obesity or anorexia with cachexia. See also adiposogenital dystrophy.

• Satin rabbit a commercial breed of rabbit with a satin-like texture and sheen to the coat. The numerous varieties differ only in color.

• Satinsky vena cava clamp scissor-action, ratchet handles, long, thin double-curved blades. Tangential vascular occlusion clamp.

• satratoxins [sa′tr -tok″sin] trichothecene toxins produced by Stachybotrys chartarum. Classified as C, D, F, G, H depending on their chromatographic mobility.

• saturated [sach′ -rāt- d] 1. denoting an organic compound that has only single bonds between carbon atoms and is therefore less reactive than one with double bonds, e.g., saturated fatty acids. 2. holding all of a solute that can be held in solution by the solvent (saturated solution).

  • s. fatty acids see fatty acid.
• saturation [sach″ -ra′sh n] the state of being saturated, or the act of saturating.

  • s. kinetics kinetics of an enzyme reaction when the velocity of the reaction increases to a maximal value as the concentration of the substrate is increased. At the maximal value the enzyme is saturated with the substrate.
  • oxygen s. the amount of oxygen bound to hemoglobin in the blood expressed as a percentage of the maximal binding capacity.
  • oxygen s. curve graphical representation describing the relationship (usually curvilinear) between fraction of oxygen-binding sites (of a protein) that have oxygen bound to them and the partial pressure (concentration) of free oxygen.

• saturnine [sat′ r-nīn] pertaining to lead, the poisonous metal.

• saturnism [sat′ r-niz- m] lead poisoning; plumbism.

• saucerization [saw″s r-ľ-za′sh n] the excavation of tissue to form a shallow shelving depression, usually performed to facilitate drainage from infected areas of bone.

• Sauerbruch retractor simple handheld retractor with a broad blade turned down at right angles at the end. Used for short-term exposure of abdominal cavity.

• sausage boot a stuffed leather roll worn above the coronet by a horse. Used to prevent pressure by the shoe on the elbow when the horse is lying down, which may cause a shoe boil see elbow hygroma.

• sausage casing the tube used to stuff with sausage meat; some are synthetic. Small intestine is used as edible casing.

• savaging severe trauma by biting. Said of horses savaging people, sows, and bitches savaging litters.

• Savannah a hybrid cat breed derived from crossing a domestic cat with an African Serval, which it resembles in many ways, including a spotted coat. Because it is a hybrid with a wild species, there are restrictions on ownership in some US states. Australia does not permit importation of the breed.

• SAVC South African Veterinary Council.

• SAVMA Student American Veterinary Medical Association.

• saw [saw] multi-toothed cutting instrument.

  • chain s. see Pearson saw.
  • Stryker s. see Stryker saw.
  • surgical s. modeled on carpentry tools but made of sterilizable materials; used for cutting cartilage and bone.
  • wire s. very tough, braided steel wire used in obstetrics to cut through muscles and bone. Tends to clog up in skin and with viscera. Needs to be used with a protective fetotome to avoid injury to the vagina and uterus. See also Gigli wire saw.
  • wire s. introducer 1. may be a long, 3-foot, blunt needle or flexible rod with an eye at the introduced end. Used to thread wire saw through the tube of a fetotome. 2. a heavy metal bean-shaped plaque, size of a hand palm, with two holes; used to carry the end of the wire saw through the uterus, around the object to be removed, and out again through the vagina. The two ends of the saw are then threaded into the tubes of the fetotome.

• sawdust used as litter for chickens and bedding for horses and dairy cows. Sawdust made from treated timber may cause pentachlorophenol and other wood preservative poisoning. Sawdust and wood shaving bedding can be a risk factor for Klebsiella spp. mastitis in dairy cows. Fungi growing in sawdust litter in poultry houses may cause poisoning in the birds. See also Entandrophragma cylindricum, Juglans nigra.

• sawdust liver an abattoir term used to identify livers in which the external surface has the appearance of having been dusted with sawdust; multiple foci of nonsuppurative necrosis with leukocytic infiltration. The cause is not known.

• sawfly member of the insect family Pergidae. Includes Arge pullata (Denmark), Lophyrotoma interrupta (Australia), Perreyia lepida (South America). The larvae of these leaf-eating insects collect in piles under the trees they infest; cattle eat them avidly and develop acute hepatitis due to the ingestion of lophyrotomin in the larvae.

  • birch s. see Arge pullata.

• sawhorse stance see sawhorse posture.

• saxitoxin [sak′sľ-tok″sin] neurotoxic tetrahydropurine of the paralytic shellfish poisoning (PSP) toxin group from poisonous mussels, clams, and plankton; a sodium channel blocker with the same mode of action as tetrodotoxin; originates in some toxic dinoflagellates and in some Anabaena spp.

• Saxon, Saxony popular strain of Australian Merino fine or superfine woolled sheep.

• Sayre elevator [sa′ r] double-ended, handheld instrument with one rongeur-type end and one curved blade; designed for lifting periosteum off bone during surgery.

• Sb chemical symbol, antimony (L. stibium).

• SBE sporadic bovine encephalomyelitis.

• SBO specified bovine offal.

• Sc chemical symbol, scandium.

• sc subcutaneously.

• scab [skab] a crust composed of coagulated serum, blood, pus, and skin debris covering a skin lesion.

  • sheep scab colloquial term for psoroptic mange in sheep.

• scabbard trachea congenital lateral compression of the trachea; seen in horses.

• scabby cat disease a lay term for feline miliary dermatitis.

• scabby mouth see contagious ecthyma.

• scabicide [ska′bľ-sīd] 1. lethal to Sarcoptes scabiei; 2. an agent lethal to Sarcoptes scabiei.

• scabies [ska′bēz] infestation by mites of the genus Sarcoptes. See also sarcoptic mange.

  • feline s. see notoedric mange.
  • s. incognito a variant of sarcoptic mange in dogs in which there are minimal lesions, and mites are difficult or impossible to recover in skin scrapings, possibly because of the extensive grooming and generally high level of skin hygiene that lacks only the use of a scabicide. Also there are usually only a few mites present once an immunity develops. Further infection may cause a hypersensitivity, but the mites present will still be in small numbers.
  • Norwegian s. a variety characterized by immense numbers of mites and marked scaling with crusts. Seen in immunocompromised patients.

• scabietic [ska″be-et′ik] pertaining to scabies.

• Scabiosa succisa European plant in the family Dipsaceae. Contains an unidentified toxin that has caused severe irritation of the oral mucosa in cattle. Called also Succisa pratensis, devil’s bit.

• scad transitory lameness in sheep, reputed to follow frosty conditions and to be a dermatitis caused by cold injury.

• scala [ska′l ] pl. scalae [L.] a ladder-like structure, applied especially to various passages of the cochlea.

  • s. media synonymous with the cochlear duct, but more often used in descriptions of the bony labyrinth, whereas the cochlear duct is employed in descriptions of the membranous labyrinth for the space in the cochlea between the vestibular (Reissner’s) membrane and the basilar membrane.
  • s. tympani the perilymph-filled space on the lower or basilar surface of the cochlear duct within the cochlea.
  • s. vestibuli the perilymph-filled space on the upper or cupular surface of the cochlear duct within the cochlea.

• scalar [ska′l r] in electrocardiography, a single magnitude value of a recorded electrical potential, expressed in millivolts.

• scald [skawld] 1. a burn caused by a hot liquid or a hot, moist vapor; to burn in such fashion. 2. see benign footrot. 3. alopecia, pityriasis, and hair loss over the rump of the horse without dermatitis; occurs in warm wet weather when the skin is wet continuously for long periods.

  • milk s. see milk scald.
  • sheep s. see interdigital dermatitis.

• scalding plunging of pig or poultry carcasses into very hot water to facilitate scraping and dehairing and feather plucking. Chicken scalding water is 130°F for broilers (larger birds higher) applied for 1–2 minutes. Modern pig abattoirs use steam at 144–147°F for about 3 minutes. This avoids overheating the carcasses.

• scale [skāl] 1. a thin flake or compacted plate-like body, as of cornified epithelial cells. 2. a scheme or device by which some property may be measured (as hardness, weight, linear dimension). 3. to remove supragingival and subgingival plaque and calculus from teeth.

  • absolute s. a temperature scale with zero at the absolute zero of temperature.
  • Baumé s. measures the density of solutions, expresses whether they are heavier or lighter than water. Expressed as B°, Be°, or Bé°. Used to mark hydrometers.
  • Celsius s. see Celsius scale.
  • coma s. a method of assessing neurological injuries resulting from trauma. The modified Glasgow Coma Scale developed for use in dogs and cats assigns points for motor activity, brain stem reflexes, and level of consciousness.
  • contrast s. the range of opacities or contrasts on a radiograph.
  • Fahrenheit s. see Fahrenheit scale.
  • French s. see French gauge.
  • s. rot a necrotizing dermatitis of snakes manifested by multiple, small cutaneous ulcers. May be caused by poor husbandry or diet.
  • kelvin s. see kelvin scale.

• scalene muscle [ska′lēn] 1. uneven; unequally three-sided. 2. see Table 12.1I.

• scalenectomy [ska″l -nek′t -me] resection of a scalene muscle.

• scaler [ska′l r] a manual or mechanical instrument used to remove deposits from the surface of teeth.

  • sonic s. air-driven dental instrument whose tip oscillates in an elliptical (figure-of-eight) or circular fashion at frequencies of 3–8 kHz; less effective at removing calculus compared to an ultrasonic scaler, but generating less heat and therefore safer to use.
  • ultrasonic s. micromotor-driven dental instrument whose tip, depending on whether a magnetostrictive or pieozoelectric mechanism is used, oscillates in an elliptical, circular or linear (back and forth) fashion at frequencies of 18–50 kHz; plaque and calculus are removed by the mechanical chipping action of the oscillating tip, cavitation of the coolant, which is the formation and implosion of small bubbles within the coolant able to exerts a disruptive force on dental deposits, and flow of the coolant irrigating the tooth surface; must be water-cooled due to heat generated at the scaler tip.

    S-18.

    

    Scald in a horse.

• scales exfoliated epidermal cells characterized by ‘flakes’ of cells unattached to the surface.

• scaling [skāl′ing] 1. removal of tartar from teeth. See also scaler. 2. in statistical terms the changing of the scale on which a variable is measured, usually to match the scaling of another lot of data and simplify comparison.

• scallop bivalve molluscs in the family Pectinidae. There are several hundred species worldwide, but the main ones harvested commercially are the Japanese scallop (Pecten yessoensis), great Atlantic scallop (P. maximus), and giant or sea scallop (Placopecten magellanicus).

• scalpel [skal′p l] small surgical knife. The traditional fixed blade model usually has a convex edge. Modern instruments have detachable blades in a great variety of shapes and sizes. There are other more sophisticated cutting instruments such as the argon plasma scalpel, the carbon dioxide laser scalpel, the electrosurgical scalpel, and the high-energy scalpel.

• scaly [ska′le] skin condition characterized by scales; scale-like.

  • s. face, s. leg see Cnemidocoptes pilae.
• scan [skan] an image produced using a moving detector or a sweeping beam of radiation, as in scintiscanning, B-mode ultrasonography or computed tomography. Also used to describe a static imaging that is exploratory or a ‘snap-shot’ of the patient’s anatomic areas.

  • s. generator the basic mechanism in a scanning electron microscope, moving the beam across the specimen.
  • static s. in ultrasonography, a static image built up by movement of the transducer sequentially over the body. Now largely replaced by real-time ultrasonography.

• Scandinavian knuckling syndrome a syndrome of metatarsophalangeal joint extensor paresis of uncertain etiology. May occur in Australia. Bilateral knuckling of hind fetlocks, exacerbated by circling. Minority of cases also have forelimb fetlocks affected. Case fatality rate of approximately 30% with prolonged recovery in those that survive.

• scandium (Sc) [skan′de- m] a chemical element, atomic number 21, atomic weight 44.956.

• scanning [skan′ing] close visual, electronic or radiographical examination of a small area or of different isolated areas of the body.

  • s. electron microscopy (SEM) one of the two forms of electron microscopy. Provides information on the surface topography of a sample.
  • radioisotope s. production of a two-dimensional record of the gamma rays emitted by a radioactive isotope concentrated in a specific organ or tissue of the body, such as brain, kidney, or thyroid gland. See scintigraphy.

    S-19.

    

    Scalpel handles—#3, #4, and #8. Each handle size has a blade seat of a different size to accommodate a detachable blade.

    S-20.

    

    Scanning electron photomicrography of erythrocytes from a cat infected with Mycoplasma haemofelis, showing a rounded organism within an indentation on the erythrocyte surface (×1000).

  • total body s. utilization of computed tomography (CT) to examine a cross-section of the entire body. The CT scanner produces an image in the transverse plane of the part of the body being scanned. The CT data may be reformatted into multiple planes such as dorsal and sagittal.

• scanography [skan-og′r -fe] a method of making radiographs by the use of a narrow slit beneath the tube, so that, as the x-ray tube moves over the target, all the rays of the central beam pass through the part being radiographed at the same angle.

• scansorial of or pertaining to climbing, as in animals or birds with body structure or feet adapted for climbing.

• scant feces small, hard feces are passed infrequently; occur in dehydration, reduced feed intake, alimentary tract stasis.

• scapha [ska′f ] pl. scaphae [L.] the hollow inside the peripheral part of the ear flap that leads into the tubular concha.

• scaphoid [skaf′oid] 1. shaped like a boat. 2. radial carpal bone. See Table 9.

• scaphoiditis [skaf″oi-di′tis] inflammation of the scaphoid bone.

• scapula [skap′u-l ] pl. scapulae [L.] the flat triangular bone at the proximal end of the forelimb that contributes to the shoulder joint; the shoulder blade. See also Table 9.

  • flying s. dorsal scapula displacement due to bilateral rupture of the serratus ventralis muscles in cattle; believed a result of nutritional myodegeneration due to selenium deficiency.
  • winged s. see angel wings.

    S-21.

    

    Scapula of the dog.

• scapular [skap′u-l r] pertaining to the scapula.

• scapulectomy [skap″u-lek′t -me] excision or resection of the scapula.

• scapulohumeral [skap″u-lo-hu′m r- l] pertaining to the scapula and humerus.

  • s. joint shoulder joint.

• scapulopexy [skap′u-lo-pek″se] surgical fixation of the scapula to the ribs.

• scapulothoracic [skap″u-lo-th -ras′ik] pertaining to the scapula and thorax.

• scar [skahr] cicatrix; a mark remaining after the healing of a wound, such as one caused by injury, illness or surgery.

  • constricting s. contraction of scar tissue causing constriction of vascular channel or hollow viscus.
  • honorable s. in judging dogs, scars resulting from injuries suffered as a result of work are permissible and do not detract from the dog’s features.
  • hypertrophic s. an overabundance of connective tissue in a wound, identified by history of traumatized wound, infection, and histological examination reveals hairs, foreign body, pockets of infection.
  • s. tissue a dense mass of granulation tissue.

• scarification [skar″ľ-fľ-ka′sh n] production in the skin of many small superficial scratches or punctures, as for introduction of vaccine. Erroneously used to mean scarring.

• scarificator [skar′ľ-fľ-ka″t r] scarifier.

• scarifier [skar′ľ-fi″ r] an instrument with many sharp points, used in scarification.

• scarlet pimpernel [skahr′l t] Anagallis arvensis.

• scarlet red an azo dye used for demonstrating sex chromatin, basic protein and connective tissue in histology, and as a stimulant to healing in wounds. Called also Biebrich scarlet.

• scarlet runner Phaseolusvulgaris.

• Scarpa’s membrane [skahr′pah] see tympanic membrane (secondary).

• scat feces, droppings; typically of wild animals.

• Scatchard equation [skach′ rd] describes the affinity of binding of a ligand and receptor, such as antigen binding by antibody.

• scatemia alimentary toxemia in which the chemical poisons are absorbed through the intestine.

• scatology [skah-tol′ -je] study and analysis of feces, as for diagnostic purposes.

• scatoscopy [sk -tos′k -pe] examination of the feces.

• scatter [skat′ r] 1. the diffusion or deviation of x-rays produced by a medium through which the rays pass, e.g., the patient, cassette, and table. This leads to a change in direction and energy of the x-ray beam and may result in film fog. 2. the distribution of two variables in relation to each other, e.g., the numbers of a population in terms of time, place, or any other variable.

  • back s. scatter radiation originating from behind the image plane.

• scattergram [skat′ r-gram] a graph in which the values found in a statistical study are represented by disconnected, individual symbols.

• scattering [skat′ r-ing] a change in the direction of motion of a photon, sound or subatomic particle as the result of a collision or interaction.

• scavenging see anesthetic scavenging.

• SCC squamous cell carcinoma.

• SCCS self-contained-cleaning-system in an abattoir.

• Scedosporium [se-do-spor′e- m] a genus of molds in the phylum Ascomycota associated with bovine and equine abortion, bovine mastitis, eumycotic mycetomas in horses and companion animals, and rhinitis and keratitis in dogs. Contains the species S. apiospermum, S. boydii, and S. prolificans. S. prolificans has caused disseminated mycosis in compromised dogs. Previously called Pseudallescheria boydii, Allescheria boydii, and Petriellidium boydii.

• Sceletium African plant genus in the family Aizoaceae; contain soluble oxalates that cause nephrosis, uremia, and urolithiasis.

• scenario building predicting the future by assuming a series of alternative possibilities, as opposed to predicting the future solely on the basis of extrapolated mathematical data.

• scent a distinctive, agreeable odor. Animals secrete them from sweat and sebaceous glands and special scent glands. See also pheromone.

  • s. gland impaction the secretion in the gland becomes inspissated and forms an irritating foreign body that can be inflamed or infected.
  • s. hound see hound.

• scented thorn Acacianilotica subsp. kraussiana.

• Schalm classification a morphological classification system for anemias based on the erythrocyte indexes of MCV and MCHC.

• Schapendoes a medium-sized dog with a long, thick, slightly wavy coat in a range of colors, forming a top knot, mustache, and beard. The tail is long and feathered. Called also Dutch sheepdog.

• schechita see shechita.

• scheduled diseases in Commonwealth countries, diseases listed in the schedules of the regulations of the local Stock Diseases Act or similar Act. The diseases are listed as contagious, and the Act specifies that they are to be reported to the appropriate government authority with appropriate penalties for default. The schedules are included in the regulations rather than in the main body of the Act so that they can be changed without opening the Act to the Parliament.

• Schefflera actinophylla Australian tree in Araliaceae family; leaves cause stomatitis, salivation, vomiting, diarrhea in dogs that ingest them. Called also umbrella tree.

• schema [ske′m ] a plan, outline or arrangement.

• Schiff–Sherrington syndrome extensor hypertonia of the thoracic limbs and paraplegia resulting from acute, severe, compressive lesions of the thoracolumbar spinal cord that remove the inhibitory effects of neurons in the lumbar spinal cord.

• Schilling count [shil′ing] a differential leukocyte count in which the neutrophils are divided into blasts, progranulocytes, myelocytes, metamyelocytes, bands, and mature segmented cells. Called also nuclear index. The terms ‘left shift’ and ‘right shift’ are based on this classification of neutrophils by age.

• Schilling test [shil′ing] see vitamin B ₁₂ absorption test.

• Schimmelbusch mask [shim′ l-boosh″] a wire frame over which a cloth was spread and an inhalant anesthetic added. An early version of the anesthetic face-mask, designed by Dr. Curt Schimmelbusch, a German physician, around 1889.

• schindylesis [skin″d -le′sis] an articulation in which a thin plate of one bone is received into a cleft in another, as in the articulation of the perpendicular plate of the ethmoid bone with the vomer; a tongue-and-groove joint.

• Schinus [shi′n s] a genus in the plant family Anacardiaceae. Contain urushiols and have caused gastroenteritis and contact dermatitis in birds, pigs, cattle, and dogs. Includes S. molle (pepperina), S. terabinthifolius (Brazilian pepper tree).

• Schiotz tonometer [she-ets′] see indentation tonometer.

• Schipperke a small, lively dog with cobby build and thick, medium-length coat, usually black but may be another whole color, that forms a ruff around the neck and ‘coulottes’ on the back of the thighs. The head has a foxy appearance with erect pointed ears. The tail is docked to a short length. Called also Belgian barge dog. The breed is affected by mucopolysaccharidosis type IIIB.

• Schirmer tear test (STT) [shir′m r] a measure of aqueous tear production used in the diagnosis of keratoconjunctivitis sicca. A standardized strip of filter paper is inserted into the ventrolateral conjunctival sac, projecting over the lower eyelid. The length of paper wet after a specified period of time is measured and compared with normals for the species being tested. The Schirmer tear test-I is performed without prior corneal surface anesthesia and measures basal and reflex tearing. The Schirmer tear test-II is performed following corneal surface anesthesia and measures basal tearing only.

• schist(o)- word element. [Gr.] cleft, split.

• Schistocephalus a genus of tapeworms in the family Diphyllobothriidae.

  • S. solidus adults found in the intestine of birds and can cause mortality in ducks. Intermediate stages in cyprinid fishes cause marked swelling of the abdomen.

• schistocephalus a fetus with a cleft head.

• schistocormus [shis″-, skis″to-kor′m s] a fetus with a cleft trunk.

  S-22.

  

  Schirmer tear test being performed in a cat.

• schistocyte [shis′-, skis′to-sīt] schizocyte.

• schistocytosis [shis″-, skis″to-si-to′sis] schizocytosis.

• schistoglossia cleft (bifid) tongue.

• schistomelus [shis-, skis-tom′ -l s] a fetus with a cleft limb.

• schistometer an instrument for measuring the aperture between the vocal cords.

• Schistosoma [shis-, skis-tom′ -l s] a genus of elongated dioecious digenetic trematodes that inhabit blood vessels of the host. The eggs are found in the wall of the bladder, uterus, and urethra. Includes S. bovis (ruminants), S. curassoni (ruminants), S. haematobium (humans), S. incognitum (pigs, dogs), S. indicum (ruminants, horses), S. intercalatum (humans, ruminants, horses), S. japonicum (humans, many other species), S. magrebowiei (ruminants, zebra), S. lieperi (wild artiodactyls), S. mansoni (humans, wild animals), S. mattheei (most species), S. mekongi (humans, dogs), S. nasalis (ruminants, horses), S. rodhaini (dogs, rodents), S. spindale (ruminants, dogs), S. suis S. incognitum).

• schistosoma reflexus [shis″-, skis″to-so′m ] a common fetal malformation and cause of dystocia requiring a cesarean delivery. Characterized by acute angulation of the spine so that the tail lies close to the head, the thoracic, and abdominal cavities have no ventral wall and the viscera are uncontained.

• Schistosomatium [shis″-, skis″to-so-ma′she- m] a genus of flukes in the family Schistosomatidae. Found in rodents.

  • S. douthitti occurs in mesenteric veins and may cause dermatitis.
• schistosome [shis′-, skis′to-sōm] a member of the family Schistosomatidae. Includes the genera Austrobilharzia, Bilharziella, Bivitellobilharzia, Dendritobilharzia, Gigantobilharzia, Heterobilharzia, Ornithobilharzia, Pseudobilharziella, Schistosoma, Schistosomatium, Trichobilharzia.

  • s. dermatitis a disease of humans caused by invasion of the skin by the cercariae of nonhuman schistosomes, especially avian ones. Called also clam-digger’s itch, swimmer’s itch, rice-paddy itch, swamp itch.

• schistosomiasis [shis″-, skis″to-so-mi′ -sis] the disease caused by the trematode Schistosoma spp. The most common syndrome is one of hemorrhagic enteritis, anemia, and emaciation with many affected animals dying after an illness of several months. Necropsy lesions include distended mesenteric vessels filled with flukes, hemorrhagic enteritis with granuloma formation in some cases. Granulomatous lesions occur in the liver in an hepatic form of the disease. Nasal schistosomiasis, caused by Schistosoma nasalis, is characterized by nasal discharge, snoring and dyspnea. S. haematobium causes hematuria. Human infestation with cercariae causes swimmer’s itch, swamp itch. The term is also applied to the disease in dogs caused by Heterobilharzia americana, a trematode closely related to Schistosoma.

• schistosomicide [shis″-, skis″to-so′mľ-sīd] an agent that destroys schistosomes.

• schistosomus [shis″-, skis″to-so′m s] a fetus with a cleft abdomen.

  • s. reflexus the lateral edges of the somatic disk in the developing embryo curve upward instead of downward. The viscera float free in the amnion, the head and tail are curved up toward each other. The fetus creates a dystocia with the free-floating viscera, or the four limbs and the head all together, presenting in the cervical canal.

• schistothorax congenital fissure of the chest or sternum.

• schizaxon [skiz-ak′son] an axon that divides into two nearly equal branches.

• schiz(o)- word element. [Gr.] divided, split, cleft.

  S-23.

  

  Schistosoma reflexus in an aborted fetus.

• schizocyte [skiz′o-sit] an erythrocyte fragment, resulting from intravascular shearing forces, as in disseminated intravascular coagulopathy, caval syndrome, and vascular neoplasms. Also seen in liver disease, heart failure, glomerulonephropathy, and other conditions. Called also schistocyte.

• schizocytosis [skiz″o-si-to′sis] the accumulation of schizocytes in the blood.

• schizodemes parasites with similar restriction profiles of mitochondrial minicircle DNA sequences (Trypanosoma spp.).

• schizogenesis [skiz″o-jen′ -sis] reproduction by fission.

• schizogony [skľ-zog′ -ne] an asexual reproductive stage of an apicomplexan parasite (sporozoite stage) by multiple binary fission within cells in the body of the host, giving rise to merozoites.

• schizogyria [skiz″o-ji′re- ] a condition in which the cerebral convolutions have wedge-shaped cracks.

• schizont [skiz′ont] the asexual reproductive stage in the development of the Eimeria spp. and in many other coccidians, e.g., Toxoplasma spp. in the cat, following the sporozoite and trophozoite stages.

  • giant s’s. up to 300 mm in diameter occur in the abomasum of sheep and goats, as part of the life cycle of Eimeria gilruthi. An unnamed species of Eimeria produces giant schizonts in the pyloric antrum of western grey kangaroos.

• Schizotrypanum [skiz″o-trip′ -n m] see Trypanosoma.

• Schlatter–Osgood disease see Osgood–Schlatter disease.

• Schlemm’s canal [shlem] a circular venous canal at the junction of the sclera and cornea that receives aqueous humor draining from the anterior chamber. Called also scleral venous sinus, sinus venosus sclerae.

• Schlesinger’s test [shla′sing- r] a test for the presence of urobilinogen in urine, determined by a color change after the addition of zinc sulfate.

• Schmallenberg virus member of the Simbu serogroup of the genus Orthobunyavirus within the family Bunyaviridae.

• Schmallenberg virus disease an emerging arthropod-born disease affecting ruminants, first described in Germany in late 2011 and since spread throughout Europe. Transmitted by Culicoides spp. and vertically. Disease characterized by fever, reduced milk production, and diarrhea in cattle, but infection clinically inapparent in sheep and goats. Abortions, stillbirths, arthrogryposis, and hydranencephalopathy occur when cattle or sheep are infected in early pregnancy

• Schmauch bodies see Heinz body.

• Schmidt’s syndrome [shmit] see polyglandular syndrome.

  S-24.

  

  Numerous schizocytes and a helmet-shaped cell in this blood smear from a dog with stenosis of the pulmonic valve.

  S-25.

  

  Eimeria bovis schizont in an intestinal epithelial cell of a calf.

• Schmidt’s test [shmit] a test for the detection of bilirubin in feces based on the development of a pink color in a fecal sample after the addition of mercuric chloride.

• Schmidt–Waldmann vaccine an historic, early named foot-and-mouth disease vaccine composed of inactivated virus and adjuvant.

• Schmieden’s suture a technique for closing incisions of the intestinal wall, it is a continuous inverting suture through all three layers of the wall and that is then buried by a second layer of sutures.

• Schmorl’s disease [shmorl] 1. in humans, herniation of the nucleus pulposus of the intervertebral disk. 2. Fusobacterium necrophorum infection in rabbits. See necrobacillosis (2).

• Schmorl’s node [shmorl] an irregular or hemispherical bone defect in the cranial or caudal margin of the body of a vertebra into which the nucleus pulposus of the intervertebral disk herniates.

• Schnauzer a dog with hard, wiry, black or salt-and-pepper—colored coat that is short on the body but longer on the legs and face, where it forms the characteristic eyebrows, mustache, and chin whiskers. The small, v-shaped ears are set high and fold over except in countries where earcropping is practiced. The tail is docked to a short length. There are three varieties of Schnauzers, not closely related in origin and each regarded as a separate breed, similar in appearance but varying in size. The miniature (12–14 in. tall) is classed as a terrier, while the standard (17–20 in. tall) and giant (23–27 in. tall) are classed as working dogs in the US. The miniature Schnauzer is predisposed to congenital cataracts, progressive retinal atrophy, hyperlipidemia, and Schnauzer comedo syndrome. Malabsorption of vitamin B12 is an autosmal recessive trait in giant Schnauzers.

• schnoodles a hybrid name used to describe dogs produced from crossing Schnauzers and Poodles. Not a recognized breed. See designer dogs.

• schochet see shochet.

• Schoengastia see harvest mite.

• Schoenocaulon officinalis a member of the Liliaceae family; the plant source of veratrine for pharmaceutical use.

• Schoenus genus of the plant family Cyperaceae; two Australian species contain the toxin galegine; causes fatal pulmonary edema and hydrothorax in sheep when eaten in quantity. Includes S. asperocarpus, S. rigens. Called also poison sedge.

• schomer see shomer.

• school to train a horse in dressage or Greyhounds to perform on the racetrack. See also riding school.

• schooling see school.

• Schroeder–Thomas splint see Schroeder–Thomas splint.

• Schultz–Dale reaction, test [shoolts′ dāl′] an experimental in vitro test for hypersensitivity in which a strip of smooth muscle is removed from a sensitized animal and exposed to specific antigen, resulting in contraction.

• Schwalbe’s ring a circular ridge composed of collagenous fibers marking the peripheral termination of Descemet’s membrane. Called also Schwalbe’s line.

• Schwann cell [shvahn] any of the large nucleated cells whose cell membrane spirally enwraps the axons of myelinated peripheral neurons supplying the myelin sheath between two nodes of Ranvier.

• schwannoma [shwah-no′m ] a neoplasm originating from Schwann cells (of the myelin sheath). Most occur in the skin, but they are also found in nerve trunks and roots. The Schwann cell is also a component of neurofibromas. Called also neurilemmoma.

  • cardiac s. single or multiple round or nodular masses on the epicardial surface or within the myocardium.
  • granular cell s. see granular cell tumor.

• Schweinepest [Ger.] hog cholera; now called classical swine fever.

• Schweinsberger disease pyrrolizidine alkalosis caused by the ingestion of Senecio spp.

• schwitzkrankheitHyalomma toxicosis. See sweating sickness.

• sciage [se-ahzh′] [Fr.] a sawing movement of the hand in massage.

• sciascopy see retinoscopy.

• sciatic [si-at′ik] pertaining to the ischium.

  • s. nerve a large nerve extending from the lumbosacral plexus down the thigh, with branches throughout the lower leg and foot. It is the widest nerve of the body and one of the longest. See also Table 13.
  • s. nerve degeneration occurs during parturition in cows due to passage of a large fetus through the pelvic canal causing pressure and subsequent degeneration of one or both sciatic nerves leading to posterior paresis or paralysis.
  • s. nerve paralysis injury to the sciatic nerve, commonly during difficult parturition in heifers, causes weakness or paralysis of one hindleg, and the animal is recumbent. See also maternal obstetric paralysis.

• SCID severe combined immunodeficiency. See combined immune deficiency syndrome (disease).

• scientific method the process of extending knowledge by forming a hypothesis based on observations and epidemiological patterns, which is then tested on a subset of the total population, then generalizing the results to the appropriate population through the process of inductive logic. Before implementation of the hypotheses, they should be tested by studies planned on the basis that the hypothesis will be proved or denied. Peer review of theories and results are an essential component.

• Scilla [sil′ ] see Drimia, Urginea.

• scillerin A cardiac glycoside found in Scilla maritima.

• scilliroside [sil′ir-o-sīd] cardiac glucoside in Drimia maritima.

• scintigram [sin′tľ-gram] an image produced by scintigraphy.

• scintigraphy [sin-tig′r -fe] the production of two-dimensional images of the distribution of radioactivity in tissues after the internal administration of a radiopharmaceutical imaging agent, the images being obtained by a scintillation camera.

• scintillation [sin″tľ-la′sh n] 1. the emission of sparks. 2. a particle emitted in disintegration of a radioactive element.

  • s. camera a detector that records a photographic image of the distribution of the radioactivity of an organ after the administration of a radionuclide. A sequence of images records the uptake and the distribution of the radionuclide.
  • s. counter see scintillation counter.

• scintiphotography [sin″tľ-fo-tog′r -fe] scintigraphy.

• scintiscan [sin′tľ-skan] a two-dimensional representation (map) of the gamma rays emitted by a radioisotope, revealing its concentration in a specific organ or tissue.

• scintiscanner [sin″tľ-skan′ r] the system of equipment used to make a scintiscan.

• scirrh(o)- word element. [Gr.] hard.

  S-26.

  

  Sciatic nerve paralysis from improper site of intramuscular injection.

  S-27.

  

  Scintiscan of a cat with bilateral thyroid enlargement.

• scirrhoid [skir′oid] resembling scirrhous carcinoma.

• scirrhous [skir′ s] hard or indurated.

  • s. carcinoma carcinoma with a hard structure owing to the formation of dense connective tissue in the stroma (desmoplasia).
  • s. cord enlargement of the stump of the spermatic cord, common only in pigs and horses, and usually obvious within a few weeks of castration. The swelling may cause lameness, is painful, and may be accompanied by systemic signs of fever and toxemia. The lesion is a mass of fibrous tissue interspersed with small abscess cavities and sinus tracts.
• scissors [siz′ rz] cutting instruments consisting of two blades pivoted centrally. The blades are closed and material cut by closing the handles. In cutting tissue, the preferred technique is to hold the blades in a firmly half-closed position and to push the instrument along the grain of the tissues (push-cut). Available in a variety of shapes, lengths, and weights. The blades may be curved or straight. Frequently classified by the point shape (sharp-sharp, blunt-sharp, blunt-blunt).

  • bandage s. designed for cutting tight bandages on patients without cutting the patient. Have one blade with a knob at the point for slipping under the bandage. See also Knowles scissors and Lister scissors.
  • barber s. sharp-pointed scissors with a finger lever on one of the finger grips. Designed for hand cutting a limited area of hair.
  • blunt-sharp s. see standard surgical scissors (below).
  • corneal section s. small, with angled blades designed specifically for sectioning cornea in ophthalmic microsurgery. See also Castroviejo ophthalmic instruments.
  • dissection s. used for separating tissues. See Mayo scissors, Metzenbaum scissors.
  • iris s. small, 3-4 in. long with sharp points, for ophthalmic surgery.
  • plaster s. robust for the cutting of plaster casts. See plaster shears, Seutin shears.
  • Potts-Smith s. sharp-sharp scissors that are available with a variety of angled blades for cardiovascular procedures.
  • standard surgical s. have one narrow sharp-pointed and one wide, bluntpointed blade. Called also blunt-sharp scissors.
  • stitch s., suture s. for stitch removal; have a hook-shaped point on one blade to hook under the stitch before cutting it with the opposing blade.
  • tenotomy s. small, 4 in. long with narrow blades and rounded tips for ophthalmic surgery. A popular version is called Stevens tenotomy scissors.
  • thoracic s. very long, up to 14 in. scissors for reaching deeply located tissues. See Nelson scissors.
  • toenail s. for trimming claws and beaks. May be guillotine or scissors style; see White scissors.
  • uterine s. 9 in. long with long handles and short jaws. See Mayo scissors.
  • wire suture s. short, strong construction with very short, sharp-pointed, angled blades.

• scissura pl. scissurae [L.] an incisure; a splitting.

• sclera [sklēr′ ] pl. sclerae [L.] the tough, white, fibrous outer coat of the eye occupying the posterior s4/5 of the globe and continuous anteriorly with the cornea. The scleral stroma is banded by loose connective tissue the lamina fusca internally and episclera externally.

  • s. inflammation see scleritis.

• scleradenitis [sklēr″ad- -ni′tis] inflammation and hardening of a gland.

• scleral [sklēr′ l] pertaining to sclera.

  • s. ectasia see sclerectasia.
  • s. fixation sutures suture material placed into the episclera (Tenon’s capsule) posterior to the corneoscleral limbus for immobilizing and controlling the position of the globe during ocular surgery.

    S-28.

    

    Scleral hemorrhage in a calf.

• sclerectasia [sklēr″ k-ta′zh] a regional thinning of the sclera resulting in outward bulging sometimes with associated staphyloma. Part of the Collie eye anomaly symdrome.

• sclerectoiridodialysis [skl -rek″to-ir″ľ-do-di-al′ľ-sis] sclerectomy and iridodialysis for glaucoma.

• sclerectomy [skl -rek′t -me] 1. excision of part of the sclera. 2. removal of sclerosed parts of the middle ear after otitis media.

• sclerema [skl -re′m] induration of the subcutaneous fat.

• scleriritomy [sklēr″ľ-rit′ -me] incision of the sclera and iris in anterior staphyloma.

• scleritis [skl -ri′tis] inflammation of the sclera. Often categorized as superficial (episcleritis) or deep (true scleritis).

  • anterior s. inflammation of the sclera anterior to the equator of the globe and therefore typically visible behind the corneoscleral limbus.
  • necrotizing s. a rare form of scleral inflammation of dogs in which the sclera becomes necrotic, malacic, and thinned. May lead to globe rupture.
  • nodular s. see nodular granulomatous episcleritis.
  • posterior s. inflammation of the sclera posterior to the equator of the globe and therefore typically not externally visible. Evident as periocular inflammation, sometimes with exophthalmos and sometimes chori oretinitis.

• scler(o)- word element. [Gr.] hard, relationship to sclera.

• scleroblastema [sklēr″o-blas-te′m ] the embryonic tissue from which bone is formed.

• Scleroblitum atriplicinum toxic plant in the family Chenopodiaceae; causes soluble oxalate poisoning manifested by nephrosis, uremia, urolithiasis. Called also Chenopodium atriplicinum, lamb’s tongue.

• sclerochoroiditis [sklēr″o-ko″roi-di′tis] inflammation of the sclera and choroid.

• sclerocornea [sklēr″o-kor′ne- ] the sclera and cornea regarded as one; sometimes called corneosclera..

• Scleroderma genus of toxic macrofungi; toadstools containing an unidentified toxin causing vomiting, tenesmus. Includes S. aurantium, S. citrinum, S. flavidum.

• scleroderma [sklēr″o-dur′m ] chronic hardening and shrinking of the connective tissues of any organ of the body, including the skin, heart, esophagus, kidney, and lung. The skin may be thickened, hard, and rigid, and pigmented patches may occur.

• sclerectoiridectomy [skl -rek″to-ir″ľ-dek′t -me] excision of part of the sclera and of the iris for glaucoma. Not done in veterinary glaucomas.

• sclerogenous [skl -roj′-n s] producing sclerosis or a hard tissue or material.

• scleroiritis [sklēr″o-i-ri′tis] inflammation of the sclera and iris.

• sclerokeratectomy excision of a portion of cornea and sclera.

• sclerokeratitis [sklēr″o-ker″ -ti′tis] inflammation of the sclera and cornea.

• Sclerolaena Australian genus of plants in family Chenopodiaceae; contain soluble oxalates that cause nephrosis, uremia, urolithiasis. Include S. anisacanthoides (yellow burr), S. calcarata (red or copper burr), S. muricata (prickly rolypoly).

• scleroma [skl -ro′m] a hardened patch or induration of skin or mucous membrane.

• scleromalacia [sklēr″o-m -la′sh] degeneration and softening of the sclera, usually due to collagenolytic enzyme production.

• scleronyxis [sklēr″o-nik′sis] surgical puncture of the sclera.

• sclero-oophoritis [sklēr″o-o-of″ -ri′tis] sclerosing inflammation of the ovary.

• sclerophthalmia [sklēr″of-thal′me- ] encroachment of the sclera upon the cornea so that only a portion of the axial cornea remains clear.

• scleroplasty plastic repair of the sclera.

• scleroprotein [sklēr″o-pro′tēn] a simple protein characterized by its insolubility and its fibrous structure; it usually serves a supportive or protective function in the body, e.g., collagens, elastins, and keratins.

• sclerosant [skl -ro′s nt] sclerosing agent.

• sclerose [skl -rōs′] to become, or cause to become, hardened.

• sclerosing agents [skl -rōs′ing] used to create scar tissue and obliterate a lumen or joint space or to stabilize a moving part. Called also internal blister, e.g., ethanolamine oleate, sodium iodide.

• sclerosis [skl -ro′sis] an induration or hardening, especially hardening of a part from chronic inflammation and in disease of the interstitial substance.

  • arteriolar s. arteriolosclerosis.
  • lenticular s. see nuclear sclerosis (below).
  • nuclear s. increased density of the central lens seen as normal feature of aging in all animals but most notable in dogs. Causes a gray-blue central haze within the lens that can be mistaken for cataract formation, but that does not cause blindness or prevent funduscopic examination.

• scleroskeleton [sklēr″o-skel′ -ton] the part of the bony skeleton formed by ossification in ligaments, fasciae, and tendons.

• sclerostenosis [sklēr″o-st -no′sis] induration or hardening combined with contraction.

• sclerostomy [skl -ros′t -me] surgical creation of an opening through the sclera for the relief of glaucoma.

• sclerotherapy [sklēr″o-ther′ -pe] the injection of sclerosing agents; for example, injection into the medial patellar ligament to treat intermittent upward fixation of the patella in horses, or injection into the distal tarsal joints to reduce the pain of osteoarthritis in these low-motion joints (‘bone spavin’).

• sclerotica [skl -rot′ľ-k] [L.] sclera.

• Sclerotinia sclerotiorum [sklēr″o-tin′e- ] mold in the phylum Ascomycota that is a pathogen of commercial celery, which is toxic when infested with the fungus.

• sclerotitis [sklēr″o-ti′tis] scleritis.

• sclerotium [skl -ro′she- m] pl. sclerotia a hard blackish mass of mycelia formed during the resting phase by certain fungi, such as Claviceps spp., in place of the seed in the seed head of a grass species. The source of the mycotoxins that cause ergotism.

• sclerotome [sklēr′o-tōm] 1. an instrument used in incision of the sclera. 2. the area of a bone innervated from a single spinal segment. 3. one of the paired segmented masses of mesenchymal tissue, separated from the ventromedial part of a somite, which develop into vertebrae and ribs.

• sclerotomy [skl -rot′ -me] surgical incision of the sclera.

  • anterior s. the opening of the anterior chamber of the eye, chiefly done for treatment of human glaucoma. Not a usual procedure in the treatment of glaucoma in veterinary ophthalmology.
  • posterior s. an opening made into the vitreous through the sclera, as for repair of detachment of the retina or the removal of a foreign body.
• sclerous [sklēr′ s] hard; indurated.

  • s. tissues the cartilaginous, fibrous and osseous tissues.
• Scolecobasidium genus of dematiaceous molds within the phylum Ascomycota, some of which can cause of phaeohyphomycosis. Some are now classified as Ochroconis.

  • S. humicola recovered from cats, a tortoise and fish. Now classified as Ochroconis humicola.
  • S. tshawytschae a cause of disease in fish. Previously classified as Ochroconis tshawytschae.

• scolex [sko′leks] pl. scoleces [Gr.] the attachment organ of a tapeworm, generally considered the anterior, or cephalic, end.

• scoli(o)- word element. [Gr.] crooked, twisted.

• scoliokyphosis [sko″le-o-ki-fo′sis] combined lateral (scoliosis) and ventral (kyphosis) curvatures of the spine.

• scoliosis [sko″le-o′sis] lateral deviation in the normally straight vertical line of the spine; it may or may not include rotation or deformity of the vertebrae.

• Scolopendra [sko″lo-pen′dr ] a genus of arthropods in the class Myriapoda. Called also centipede (Chilopoda). They have poison claws used to stun prey and can cause a painful bite to an animal.

  • S. gigantea a large tropical centipede credited as being able to kill a human.

• scooting sliding along on the ground while sitting on the perineal area and with the hindlimbs extended forward. A form of behavior limited largely to dogs and occasionally cats, caused by any irritation in the perineal area, chiefly anal sac impaction.

• scopolamine [sko-pol′ -mēn] an anticholinergic alkaloid derived from various plants, used as the hydrobromide in parasympathetic blockade and as a central nervous system depressant.

  S-29.

  

  Ergot sclerotia in some seed of a seed head of basin wildrye (Elymus cinereus).

  S-30.

  

  Scoliosis in a newborn foal.

• Scopulariopsis [skop″u-lar″e-op′sis] a mold in the phylum Ascomycota. A cause of hyalohyphomycosis.

  • S. brevicaulis an uncommon cause of dermatophytosis (ringworm) in cattle.
  • -scopy word element. [Gr.] examination of.
  • scoracratia fecal incontinence.
  • scorbutic [skor-bu′tik] pertaining to scurvy.
  • score [skor] a rating, usually expressed numerically, based on specific achievement or the degree to which certain qualities are manifest. See also body condition score, condition scoring, Injury Severity Score.

    • linear s. for somatic cell counts in milk (SCCs) convert SCC logarithmically from cells per milliliter to a linear score from 0 to 9. The linear score has a straight line, inverse relationship with milk yield. An increase of 1 in the linear score is associated with a 400-lb decrease in lactation milk yield or a 1.5-lb drop in daily yield.
    • trauma s. a numerical assessment of injuries suffered as a result of trauma. Several systems are used, including the Glasgow Coma Scale and the Revised Trauma Score. See also coma scale.
    • vertebral heart s. (VHS) see vertebral heart score.
  • scorpion [skor′pe- n] eight-legged, venomous arthropod of varying sizes but all possessing massive claws at the head and a flexible, segmented tail, which is carried in a characteristic forward curve over the back and has a sting in it. Stings by most of the >1000 species have only local effects, but some cause serious systemic effects. There are several species, including Tityus, Centruroides, Androctonus.

    • book s’s. arachnids in many families and genera in the order Pseudoscorpionida. Called also false scorpions, pseudoscorpions.
    • false s’s. see book scorpions (above).
  • scorpionfish highly venomous fish in the family Scorpaenidae; includes bullrout, lionfish, stonefish, and firefish, all capable of administering a very painful sting from their spines. Although colorful and unusual in appearance with their covering of spines and spiny fins, most would be called ‘ugly’, but some are seen to be attractive and are kept as aquarium fish.
  • Scotch collie see Collie.
  • Scotchcast see fiberglass cast.
  • scot(o)- word element. [Gr.] darkness.
  • scotochromogen [sko″to-kro′mo-j n] a microorganism whose pigmentation develops in the dark, used particularly in the classification of mycobacteria.
  • scotochromogenic [sko″to-kro″mo-jen′ik] producing scotochromogen.
  • scotopsin [sko-top′sin] the protein moiety in the retinal rods that combines with 11-cis-retinal to form rhodopsin that in turn reacts with light and splits into scotopsin and all-trans retinal.
  • Scottish blackface a breed of carpetwool and meat sheep with a black or pied face. From northern England and Scotland. See also blackfaced mountain sheep.
  • Scottish deerhound a very large (75–110 lb; 28–32 in. tall) dog with medium-length, ragged, usually dark gray hair, long neck, and quite long tail. The coat forms a ‘mane’ on the neck. The head is relatively small and elongated with small, pendant ears. Said to resemble a very large, thickboned, rough-coated Greyhound. In the UK, called simply Deerhound. The breed is predisposed to osteosarcoma, gastric dilatation-volvulus, and cardiomyopathy.
  • Scottish fancy an old, ornamental breed of canaries, popular in Victorian times. It is a long, slim bird, with a characteristic posture. The body is curved, head thrust forward, and tail carried under the perch, forming the shape of a crescent moon.
  • Scottish fold a breed of cats all of which trace their parentage to a mutant Scottish farm cat. Their distinctive feature is the forward and downward folding of ear cartilages that becomes apparent as kittens mature. This is inherited as a dominant trait that when homozygous is associated with multiple cartilaginous and bony malformations. To avoid these defects, Scottish fold cats are bred to normal eared cats, and about half the offspring are otherwise normal cats with the fold. Because of the genetic basis for this trait, there are several variations, all of which may occur in the same litter. Scottish fold, longhair and shorthair, and Scottish straight, longhair and shorthair. These may be recognized as separate breeds.
  • Scottish osteodystrophy the cartilaginous and bony malformations associated with the Scottish fold trait in cats. Called also Scottish fold osteochondrodysplasia.
  • Scottish terrier a small (18–22 lb), thickset dog with short legs. The coat is hard and wiry, trimmed to a short length on the body but allowed to be full and longer on the legs, under the body, and over the eyes and around the muzzle where it forms a beard. It is most often black, but may also be wheaten or brindled. The head is long and the ears sharply pointed and erect. The tail is docked to a medium length and carried upright. Gained celebrity status as the pet of Presidents Franklin Roosevelt, Dwight Eisenhower, and George W. Bush. The breed is affected by Scottie cramp, craniomandibular osteopathy, cystinuria, vacuolar hepatopathy, von Willebrand disease, and atopic dermatitis. Called also ‘diehard’, Aberdeen terrier, and most often, Scottie.
  • Scottie cramp see Scottie cramp.
  • scour, scours 1. the chemical and physical cleaning of fleece wool. 2. diarrhea. See also calf scours.

    • dietetic s. see dietary diarrhea.
    • grower pig s. see nonspecific colitis.
    • peat s. see secondary nutritional copper deficiency.
    • s. weed see Sisyrinchium.
    • white s. diarrhea in newborn animals on a milk diet. The name is usually used with reference to dietary diarrhea in which no bacteria or virus is etiologically involved.
    • s. worm includes the genera Trichostrongylus, Ostertagia, Cooperia and Nematodirus spp.
  • scouring characterized by scour.

    • s. disease a colloquial name for secondary nutritional copper deficiency.

      S-31.

      

      Scottish blackface sheep.

      S-32.

      

      Scottish terrier.

  • SCPK serum creatine phosphokinase. Increase in “activity” in serum is indicative of muscle damage.
  • scr scruple.
  • scraper see tartar scaler.
  • scrapie [skra′pe] an infectious, nonfebrile, chronic, fatal disease of sheep and goats transmitted primarily by contact with infected sheep and from environmental contamination. There is a very long incubation period of at least 2 years. Characterized by clinical signs of pruritus, behavioral change, abnormalities of gait, wasting, recumbency, and a long illness of about 6 months. The oldest recognized transmissible spongiform encephalopathy, caused by prion infection. Susceptibility to scrapie is genetically determined, and control programs are developed to select scrapie-resistant sheep. A disease notifiable to the OIE (see Table 21).

    • s. agent see prion.
    • s.-associated fibrils characteristic proteinaceous fibrils in the neurons of sheep with scrapie; the fibrils consist of membrane glycoprotein the DNA of which exists in the patient’s brain cells. The glycoprotein accumulates because horizontally acquired scrapie agent induces transcription of the related host chromosomal gene and converts it to a polymerized proteinase-resistant fibrillar form.
    • atypical s. a noncontagious, sporadic form of scrapie affecting very small numbers of older sheep. Affected sheep display predominantly ataxia in the absence of pruritus, and neuropathological findings are largely restricted to the cerebellar and cerebral cortices Distinguished from classical scrapie on the basis of the associated neuropathology and properties of the disease-associated prion protein on Western blots. Since its initial detection in Norway, atypical scrapie has been reported in sheep in the majority of European countries (including in regions free of classical scrapie) and in the Falkland Islands, the US, Canada, New Zealand, and Australia.
    • s. eradication programs most countries with scrapie have established scrapie eradication or scrapie monitoring schemes based on genotyping. These are driven by concerns for public health. The BSE epidemic of the early 1990s, the connection between BSE and variant Creutzfeldt-Jakob disease (vCJD) in humans, and the experiments showing oral transmission of BSE to sheep, giving rise to scrapie-like symptoms, have raised the possibility that BSE might exist in sheep posing a further risk to human health. Accordingly, the 2003 EU-Directive No 1915/2003 directs every member state to establish a breeding program based on scrapie resistance. Most countries have programs that have marked similarities and have both voluntary and compulsory aspects. Examples are the National Scrapie Plan in the UK, a voluntary breeding program that genotypes both ewes and rams in a flock and encourages breeding practices that will increase the frequency of resistant scrapie alleles and eradicate susceptible ones. The UK also has a Compulsory Scrapie Flocks Scheme where flocks with confirmed scrapie cases on their farms will either have their sheep flocks genotype tested so that those animals more susceptible to disease can be identified and removed or the whole flock slaughtered and disposed of. The equivalent in the US is the USDA Genetics Based Flock Clean-Up and Monitoring Plan. Progress has been achieved in the prevention of scrapie in sheep as a result of these programs.
    • s. eyelid test the presence of the scrapie agent in lymphoid tissue allows its detection in the lymphoid tissue of the third eyelid in live sheep. This is in contrast to the BSE agent in cattle that does not occur in lymphoid tissue and for which there is no ante mortem test.

      S-33.

      

      Scrapie. Suffolk ram with scrapie showing wool loss as the result of pruritus.

    • s. genotyping susceptibility to scrapie is associated with polymorphisms in the ovine prion protein (PrP) gene at codons 136, 154 and 171. Genotyping can establish resistant sheep and genotype testing for susceptibility to scrapie is a key element of the scrapie eradication program.
  • scraping removal of superficial layers of skin after scalding of pig carcasses, see also skin scraping
  • scratch test [skrach] see pinnal pedal reflex.
  • Scotch cramp see Scottie cramp.
  • scratches [skrach′ z] 1. excoriations caused accidentally or during rubbing to ease pruritus. 2. excoriations across the back of the pastern in a horse with the early stages of greasy heel. These are very painful and are the cause of the severe lameness evident at this stage of the disease. called also pruritic pastern dermatitis.
  • scratching 1. the common motor response to pruritus in dogs and cats. It frequently causes more severe injury and secondary infection to the skin. 2. withdrawing a horse or Greyhound from a race after it has finally accepted. 3. a rodeo term for when a horse’s sides are raked with spurs.
  • screen [skrēn] 1. in radiology and diagnostic imaging, a framework or agent used as a shield or protector. 2. to examine. See screening.

    • fast s. intensifying screen that has a large response to x-radiation permitting a reduction in radiation exposure.
    • s. film film manufactured to be used with intensifying screens. Rated as standard, fast or ultrafast speeds depending on the response to x-radiation.
    • rare-earth s. see rare-earth intensifying screen.
  • screening [skrēn′ing] 1. examination of a large sample of animals in a population in order to detect the presence of disease or to ascertain the prevalence of certain diseases, such as tuberculosis or diabetes mellitus. 2. in diagnostic tests, the use of a test that has a high sensitivity but often only a moderate specificity. Usually this is a quick and cheap test that is followed by a more expensive but more accurate test carried out on the positive reactors to the screening test. 3. fluoroscopy or image intensification (Great Britain).

    • biochemical s. using biochemical tests for purposes of detecting the presence of a disease.
    • multiphasic s., multiple s. simultaneous examination of a population for several different diseases.
    • preventive s. screening of a population with a preventive medical program in prospect.
    • s. test any test, e.g., tuberculin, brucellosis tests, used to screen a population.
  • screw [skroo] 1. a mechanical device for fixing one object to another, characterized by a spiral ridge cut on the external surface of a cylindrical rod of decreasing diameter toward its point. This is a male screw. In a female screw, the screw is cut on the inside of a cylindrical cavity. 2. a colloquial term for a worn out or inferior horse.

    • AISF bone s. see buttress thread bone screw (below).
    • buttress thread bone s. the thread is not a simple V as in the standard thread but has one side of the groove at right angles to the direction of the screw and the other side at a 45° angle. Called also AISF, Howmett compression, Richards–Bechtol.

      S-34.

      

      Carpal radiograph demonstrating transphyseal bridging using a ’single screw’ technique.

    • cancellous bone s. has a coarse thread; threaded to only the first third of the length of the screw.
    • cortical s. threaded the full length of the screw; fine thread to hold in dense bone.
    • Howmett compression bone s. see buttress thread bone screw (above).
    • lag bone s. used as a compressing unit between two fragments with the first half of the screw near the point threaded, with the diameter of the ridges greater than that of the unthreaded half near the head. As the ridged part of the screw bites in the walls of the drill hole in the distal fragment, the unthreaded part is free to move within the drill hole in the proximal fragment, thus compressing the two pieces of bone together.
    • locking s. a screw with a thread incorporated into the screw head designed to engage with a locking plate. As the screw is tightened, it ‘locks’ to the plate, thus stabilizing the segments without the need to compress the bone to the plate.
    • Richards–Bechtol bone s. see buttress thread bone screw (above).
    • standard bone s. with a V thread the full length of the screw, with a single slot, cruciate or Phillips head.
    • transfixation s. orthopedic screw used to reattach bone fragments to a solid skeletal part. The proximal part near the head is not threaded and needs to be of a smaller diameter than the threaded portion nearer the tip.
  • screw-neck twisting of the neck causing rotation of the head. Called also torticollis.
  • screw-tail inherited tail formation in some breeds of dogs with naturally short tails, e.g., British bulldog, in which there are usually multiple malformations of the coccygeal vertebrae producing a curled or otherwise distorted, stumpy tail. Sometimes called ingrown tail.

    • s. dermatitis irritation and sometimes significant secondary infection occurring in the skin fold surrounding the base of a screw-tail. See also fold dermatitis.
  • screw-worm [skroo′w rm] the larvae of Cochliomyia (formerly Callitroga), Chrysomya bezziana, and Passeromyia.

    • s. myiasis invasion of normal skin wounds by maggots of Cochliomyia, Chrysomya bezziana, and Passeromyia flies. Large masses of tissue may be destroyed, and the case fatality rate approximates 100%. All animal species including humans are susceptible. A disease notifiable to the OIE (see Table 21).
    • New world s.-w.Cochliomyia hominivorax.
    • Old world s.-w.Chrysomya bezziana.
  • scRNA small cytoplasmic RNA.
  • scrobicPaspalum scrobiculatum; toxic when infested with Claviceps paspali.
  • scrobiculate [skro-bik′u-lāt] marked with pits.
  • Scrophularia aquatica European member of plant family Scrophulariaceae. Probably contain toxic cardiac glycosides; causes excitement, tachypnea, pupillary dilatation, oral mucosal congestion and ulceration, dysuria, and profuse diarrhea. Called also water figwort, water betony.
  • scrotal [skro′t l] pertaining to the scrotum.

    • s. abscess usually the result of infection at the time of castration and absence of drainage from the site. May be accompanied by extensive local cellulitis.
    • s. anomalies include aplasia, congenital cleft, and bifurcation.
    • s. circumference an essential part of the examination of a ruminant male for breeding soundness. A special tape is used, and the measurement taken at the point of greatest diameter of the scrotum and contents—usually within the range of 13.5–16 in. is considered normal for adult bulls.
    • s. fat fat accumulates in the scrotum of most fat males; it is most obvious in castrates.

      S-35.

      

      Larvae of a screw-worm fly, Cochliomyia hominivorax. Hendrix, C.M., Robinson, Diagnostic Parasitology for Veterinary Technicians, 4th ed. Mosby, 2012.

  • scrotectomy [skro-tek′t -me] excision of part or all of the scrotum.
  • scrotitis [skro-ti′tis] inflammation of the scrotum.
  • scrotocele scrotal hernia.
  • scrotoplasty [skro′to-plas″te] plastic reconstruction of the scrotum.
  • scrotum [skro′t m] the pouch that contains the testes and their accessory organs. It is composed of skin, the dartos, fascia, and the parietal layer of tunica vaginalis.
  • scrub 1. low trees and bushes. Called also browse. Edible enough for livestock to graze them especially when more conventional feed is short. Lopping of this material for feeding is a husbandry practice in some arid zones. Lends itself to indigestion in ruminants because of its indigestibility, especially if it is the main article of diet. 2. to cleanse by vigorous scrubbing with a brush. See also surgical scrub (below).

    • s. animal one from grade parents, nondescript, and not showing the predominant characteristics of any breed. Generally used only with agricultural animals.
    • s. kurrajong Pimeleamicrocephala, P. pauciflora.
    • s. suit the outer, protective clothing worn by operating room personnel. Usually made from cotton material and worn to minimize contamination in the surgical suite.
    • surgical s. the ritualistic presurgical preparation of hands and arms by surgeons and their assistants. Includes thorough, vigorous, and systematic cleaning with a brush of all skin surfaces. Persons prepared in this manner are then considered ‘scrubbed-up’, ready to take part in the surgical procedure, and are not allowed to touch any nonsterile surfaces.
    • s. tick see Ixodes holocyclus.
    • s.-up see scrub (2).
  • scrubbed-up see surgical scrub.
  • scruple [skroo′p l] 1. a unit of weight of the apothecaries’ system, equal to 20 grains, which is the equivalent of 1.296 g. 2. conscience, moral judgement, integrity.
  • scur vestigial frontal horn at the normal site in an animal expected to be polled. It is not attached to the skull, and there may or may not be an associated bony protuberance beneath it. The animal is not acceptable as being genetically polled.
  • scurf loose, dry scales on the haircoat and skin. May be a sign of dry skin or associated with a variety of skin diseases.
  • scurvy [skur′ve] the disease caused by a nutritional deficiency of ascorbic acid (vitamin C).

    • s. rickets see hypertrophic osteodystrophy.
  • scute [skūt] any squama or scale-like structure, especially one of the thick epidermal plates on tortoise shells or on the legs and feet of birds.

    • necrotizing s. disease necrosis of the external portion of the scute associated with Fusarium semitectum.
  • scutiform [sku′tľ-form] shaped like a shield.
  • Scutigera see johnny hairy-legs.
  • scutulum [sku′tu-l m] pl. scutula [L.] one of the disk- or saucer-like crusts characteristic of favus.
  • scutum [sku′t m] 1. scute. 2. a protective covering or shield, e.g., a chitinous plate in the exoskeleton of hard-bodied ticks. 3. a pressure pad that serves as a bearing surface for tendons as they bend around a prominence. The horse digit bears three scuta over the fetlock, pastern, and coffin joints for the passage of the deep digital flexor tendon.
  • scybalous [sib′ -l s] of the nature of a scybalum.
  • scybalum [sib′ -l m] pl. scybala [Gr.] a hard mass of fecal matter in the intestine. See also fecalith.
  • scyphoid shaped like a cup or goblet.
  • Scyphozoa [si″fo-zo′ ] the class of true jellyfish; in the phylum Cnidaria.
  • SD 1. streptodornase. 2. sorbitol dehydrogenase. 3. in radiology and radiotherapy, skin dose. 4. in statistics, standard deviation.
  • SDA specific dynamic action.
  • SDH sorbitol dehydrogenase.
  • SDMA symmetric dimethylarginine; excreted by the kidneys. A biomarker specific to kidney function used in commercial testing as an indicator of kidney function in dogs and cats.
  • SDS–PAGE sodium dodecyl sulfate–polyacrylamide gel electrophoresis, a method for separating proteins by molecular weight.
  • SE standard error.
  • Se chemical symbol, selenium.
  • SEA Sheltie eye anomaly; see Collie eye anomaly.
  • sea said of denizens of the ocean. Called also marine.

    • s. cage netting enclosure anchored to the sea bed or to buoys in which cultivated fish for human consumption are kept captive and fed special diets.
    • s. canary see beluga whale.
    • s. snakes members of the family Hydrophiidae, venomous snakes, inhabiting the sea, with paddle-shaped tails. Unlikely to bite unless pressed.
    • s. wasp see box jellyfish.
    • s. water water with a salinity around 35 parts per thousand. In Aquarium settings sea water substitute is often used and consists of sodium chloride—27.2; magnesium chloride—3.8; magnesium sulfate—1.6; calcium sulfate—1.3; potassium sulfate—0.9; calcium carbonate and magnesium bromide—each 0.1, all in g/L.
  • sea lion member of the family Otariidae, identifiable by having external ears. There are several genera including Otaria, the southern sealion, Zalophus, the Californian sea lion, and Eumetopius, Steller’s sea lion. Popular as performing animals in aquaria and exhibits.

    • s. virus see San Miguel sea lion virus disease.
  • seahorse (Hippocampus spp.) fish with a long snout and bent neck that gives it an equine appearance. Other characteristics of this group of fish include the bony rings or plates around their body, a prehensile tail, and the males have a brood pouch. Several species of seahorses are popular as aquarium pets.
  • seal 1. a marine mammal; member of the suborder Pinnipedia. There are two major groups, the earless seals (family Phocidae) including many species, and the eared seals (family Otariidae) including sea lions and fur seals. They are carnivorous and have four flippers that enable them to move on land and to swim. 2. a very dark brown coat color of cats, seen in brown (or sable) Burmese and on the extremities of seal-point Siamese and Colorpoint cats.

    • elephant s. there are two species in the genus Mirounga; characterized by the male’s large proboscis. The southern elephant seal (M. leonina) the largest pinned, up to 20 ft long and 9000 lb, native to Antarctica and sub-Antarctic islands, and the northern elephant seal (M. angustirostris) that is somewhat smaller and native to the Pacific coast of North America.
    • harbor s., harbour s. the common seal, 5–6 ft long, up to 300-lb body weight, and a good performer in captive aquatic shows. Called also Phoca vitulina.
    • s. pox see sealpox.
  • seal finger see Mycoplasma phocacerebrale.
  • seal-point see points.
  • sealant [se′l nt] see bone sealant.
  • sealer [se′l r] in meat hygiene terms, see shomer.
  • sealion see sea lion.
  • sealpox poxvirus disease characterized by multiple raised nodules on the head and neck of harbor seals and sea lions; caused by a virus in the genus Parapoxvirus.
  • Sealyham terrier a small (23–24 lb), stocky dog with short legs and a harsh, wiry coat that is predominantly white, but may have lemon, brown, blue, or badger pied markings on the head and ears. The coat is trimmed to a short length on the body but forms thick feathers on the legs and body and a beard with bushy ‘eyebrows’. The breed is predisposed to atopic dermatitis, lens luxation, and retinal dysplasia.
  • searcher [s rch′ r] 1. an instrument (a sound) used in examining the bladder for calculi; called also stone searcher. 2. a farrier’s tool for excavating a small hole in the sole of the hoof in a search for a puncture site. Has a slightly curved blade with a sharp cutting hook at the end. Resembles a hoof knife but the blade is much narrower.
  • season see estrus.
  • seasonal [se′z n- l] pertaining to season of the year.

    • s. air flow patterns the changes in the patterns of air flow that occur in animal housing that are ventilated by natural means, according to the seasonal variation in the environmental temperature.
    • s. anestrus see anestrus.
    • s. calvers cattle herds in which the mating is arranged so that the cows calve at a particular season of the year.
    • s. herds see seasonal calvers (above).
  • seaweed [se′wēd] sea plants harvested for livestock feed; claimed to be a rich source of minerals and vitamins. When fed to laying hens may discolor yolks.
  • sebaceous [s -ba′sh s] pertaining to or secreting sebum.

    • s. adenitis 1. inflammation of the sebaceous gland. 2. an inflammatory disease of hair follicles and sebaceous glands, in which there are abnormalities of keratinization and sebaceous secretions, and ultimately destruction of sebaceous glands. Uncommon in many breeds of dogs and rarely cats and rabbits; inherited as an autosomal recessive trait in Standard poodles and Akitas. Characterized by hyperkeratosis, dry and brittle hairs, dry adherent scales and follicular casts, and eventually alopecia.
    • s. adenoma occur in all species, but are particularly common in the skin of aged dogs and cats. Usually benign, they appear as solitary or multiple cauliflower- or wart-like growths in any location, but especially on the head.
    • s. carcinoma rare dermal malignancy in dogs and cats that is derived from sebaceous glands. Locally aggressive but distant metastatic disease is rare. Cocker Spaniel dogs may be predisposed.
    • s. cyst see sebaceous cyst.
    • s. epithelioma low-grade dermal malignancy, locally invasive but rare to metastasize, comprised of predominantly epithelial reserve cells with occasional sebaceous differentiation.
    • s. gland holocrine glands in the skin that secrete sebum usually through the hair follicles. They vary in size and activity between species and location. In dogs, large sebaceous glands are located on the dorsum of the tail (see tail gland) and at mucocutaneous junctions. In cats, large glands are located also on the dorsum of the tail, on the lip margins, and under the chin (see submental organ).
    • s. gland secretion abnormality includes sebolith, seborrhea.
    • s. secretion see sebum.
    • supracaudal s. gland see supracaudal organ.
  • Sebekia a pentastome, the larvae of which occur in fish and the adults in crocodiles.
  • sebiferous, sebiparous secreting or producing a fatty substance.
  • sebolith a calculus in a sebaceous gland.
  • seborgium (Sg) a chemical element, atomic number 106, atomic weight 271.
  • seborrhea [seb″o-re′ ] an abnormal secretion from the sebaceous glands, often associated with abnormalities of keratinization. The clinical features vary from dandruff to the formation of greasy scales and crusts with accompanying inflammation. See also seborrheic dermatitis.

    • congenital s. occurs in several dog breeds as scaling skin at birth and progressively worsening seborrhea oleosa with advancing age. Called also dirty-puppy syndrome.
    • ear margin s. see ear margin dermatosis.
    • s. oleosa moist, oily seborrhea with the formation of yellow-brown crusts. See also exudative epidermitis.
    • primary s. an inherited disorder of keratinization recognized in several breeds, particularly American cocker spaniel, English springer spaniel, West Highland white terrier, and Chinese Shar pei. Clinical signs may appear at a young age and worsen with advancing age. There is often ceruminous otitis externa and secondary bacterial; secondary Malassezia infections are common. Reported occasionally in Persian cats. In horses, it usually occurs as seborrhea of the mane and tail, rarely as a generalized disease.

      S-36.

      

      Sebaceous adenoma in a dog.

      S-37.

      

      Canine primary seborrhea. Generalized alopecia and lichenification affecting the entire cutaneous surface area.

    • secondary s. that associated with a wide variety of unrelated diseases including parasitism, pyoderma, hypersensitivity reactions, and autoimmune skin disease.
    • s. sicca characterized by focal or diffuse scaling, accumulation of scales, and a very strong odor.
  • seborrheic [seb″o-re′ik] affected with or of the nature of seborrhea.

    • s. dermatitis see seborrheic dermatitis.
    • s. keratosis see seborrheic keratosis.
  • seborrheid a seborrheic eruption.
  • sebotropic [seb″o-tro′pik] having an affinity for or a stimulating effect on sebaceous glands; promoting the excretion of sebum.
  • sebum [se′b m] the oily secretion of the sebaceous glands, whose ducts open into the hair follicles. It is composed of fat and epithelial debris from the cells of the malpighian layer, and it lubricates the skin. It is also secreted by the tarsal glands of the eyelids.
  • sec second.
  • Secale cereale [se-ka′le] cereal rye. Grown mainly as a grain crop for animal feed, production of rye bread and rye whisky. The crop may be infected with Claviceps purpurea.
  • secobarbital [se″ko-bahr′bľ-t l] a short- to intermediate-acting oxybarbiturate, historically used for sedation in pigs. Called also quinalbarbitone.
  • secodont [se′ko-dont] bladelike teeth with sharp cutting edges that produce a shearing action as seen in the carnassial teeth (i.e., the maxillary fourth premolar and mandibular first molar) of the cat and dog.
  • second (s, sec) [sek′ nd] the SI unit of time.
  • second cross progeny of a mating between a halfbred and a purebred of one of the parents.
  • second cuts short pieces of fleece wool resulting from the shearer cutting over the same area twice.
  • second cutting said of hay made from a field that has already been cut for hay in the current summer. Does not have the weeds and old growth of the first cutting hay. Alfalfa in irrigated and warm areas may have three or four cuttings.
  • second gas effect inclusion of a low solubility gas (nitrous oxide) concomitantly with another gas, such as isoflurane, results in an increase in the rate of onset of anesthesia due to an increase in the alveolar concentration
  • second messenger molecule transferring a signal from cell surface receptors to other effector molecules within the cell to produce a response; participates in signal transduction pathways.
  • second-order reactions the rate of product formation either depends directly on the product of the concentrations of two substrates (as in condensation reactions) or the square of the concentration of a single substrate (as in dimerization reactions).
  • second-set reaction, phenomenon see rejection.
  • secreta [se-kre′t ] [L.] secretion products.
  • secretagogue [se-krēt′ -gog] an agent that stimulates secretion.
  • secrete [se-krēt′] to synthesize and release a substance.
  • secretin [se-kre′tin] a hormone secreted by the mucosa of the duodenum and jejunum when acid chyme enters the intestine; carried by the blood, it stimulates the secretion of pancreatic juice and, to a lesser extent, bile and intestinal secretion.

    • s. test an examination of the gastric and duodenal contents after intravenous administration of exogenous secretin; useful in the diagnosis of disorders affecting pancreatic exocrine function, for example, pancreatitis and neoplastic disease.
  • secretinase a substance in the serum that inactivates secretin.
  • secretion [se-kre′sh n] 1. the cellular process of elaborating a specific product. This activity may range from separating a specific substance of the blood to the elaboration of a new chemical substance. 2. any substance produced by secretion. One example is the fatty substance produced by the sebaceous glands to lubricate the skin. Saliva, produced by the salivary glands, and gastric juice, secreted by specialized glands of the stomach, are both used in digestion. The secretions of the endocrine glands include various hormones and are important in the overall regulation of body processes. Secretion of milk is an essential physiological activity in all mammals. 3. categories of secretion include apocrone, holocrine, merocrine, sebaceous, serous.

    • type III s. a mechanism used by some gram-negative bacteria to secrete virulence factors, particularly into host cells using specific pili. Evolved from the mechanism used to assemble flagella.
    • type IV s. a distinct mechanism used by some gram-negative and gram-positive bacteria to secrete virulence factors using specific pili. Used by some intracellular bacteria to introduce their virulence proteins into the cytoplasm of their host cell from the phagosome. Evolved from the bacterial conjugative system.
  • secretoinhibitory [se-kre″to-in-hib′ľ-tor″e] inhibiting secretion; antisecretory.
  • secretome all of the gene products that are secreted from a cell.
  • secretomotor [se-kre″to-mo′t r] stimulating secretion; said of nerves.
  • secretory [se-kre′t -re, se′kr -tor″e] pertaining to secretion.

    • s. cells the specialized cells in a secretory gland that perform the secretory function.
    • s. component a component of secretory IgA (sIgA) that originates as part of the polymeric immunoglobulin receptor that is synthesized by epithelial cells. Following binding of IgA and translocation to the lumen, the receptor is cleaved, and the polypeptide that remains bound to sIgA is the secretory component.
    • s. diarrhea see secretory diarrhea.
    • s. endpieces see adenomere.
    • s. granules a type of secretory vesicle that contain proteins (e.g., neuropeptides, hormones) destined for secretion that are stored in the cytoplasm and released from the cell upon receiving appropriate stimulation. Called also dense-core secretory granule or dense-core secretory vesicle.
    • s. IgA (sIgA) the most abundant class of antibody found in secretions covering mucosal surfaces and consists of polymers of IgA (most commonly dimers) with their heavy chains covalently linked by a J chain and associated with the secretory component (see above). See also immunoglobulin.
  • sectio [sek′she-o] pl. sectiones [L.] section.
  • section [sek′sh n] 1. an act of cutting. 2. a cut surface. 3. a segment or subdivision of an organ.

    • abdominal s. laparotomy; incision of the abdominal wall.
    • cesarean s. delivery of a fetus by incision through the abdominal wall and uterus; see also cesarean section.
    • dorsal s. a section through the body passing at right angles to the median plane, dividing the body into dorsal and ventral parts.
    • frontal s. see dorsal section (above).
    • frozen s. a specimen cut by microtome from tissue that has been frozen; see also frozen section.
    • perineal s. external urethrotomy.
    • sagittal s. a section through the body coinciding with the sagittal suture, thus dividing the body into right and left halves.
    • serial s’s histological sections of a specimen made in consecutive order and so arranged for the purpose of microscopic examination.
    • trial s. the gradual transverse cutting of a tissue or structure, usually to ascertain its composition or to limit the incision to only one component, e.g., scar tissue surrounding a nerve.
  • sectioning preparation of sections from fixed and embedded blocks of tissue by thin shaving with a microtome.
  • sections thin shavings of fixed and embedded blocks of tissue, collected by biopsy or at necropsy examination, for histological or pathological microscopy.
  • -sectomy surgical removal of.
  • sectorial [sek-tor′e- l] cutting; said of teeth, particularly carnassial teeth. See also sectorial occlusion.
  • secundigravida [s -kun″dľ-grav′ľ-d] a female pregnant the second time; gravida II.
  • secundines [sek′ n-dēnz, se-kun′dēnz] afterbirth; the placenta and the membranes expelled after parturition.
  • secundipara [se″k n-dip′-r] a female that has had two pregnancies that resulted in birth; para II.
  • sed rate sedimentation rate.
  • sedation [s -da′sh n] 1. the allaying of irritability or excitement, especially by administration of a sedative. 2. the state so induced.

    • s. points in acupuncture used to decrease energy in a specific organ or a meridian.
  • sedative [sed′ -tiv] 1. allaying irritability and excitement. 2. an agent that calms nervousness, irritability, and excitement; a calming or tranquilizing agent. In general, sedatives depress the central nervous system and tend to cause lassitude and reduced mental activity. Some have a few additional effects, while others may also affect the cardiovascular system (e.g., have hypotensive effects). The degree of relaxation produced varies with the kind of sedative, dose, means of administration, and mental state of the patient. By causing relaxation, a sedative may help an animal go to sleep, but it does not induce sleep. (Drugs that induce sleep are known as hypnotics.) A drug may act as a sedative in small amounts and as a hypnotic in large amounts. The degree of relaxation produced varies with the kind of sedative, dose, means of administration, and mental state of the patient. By causing relaxation, a sedative may help an animal go to sleep, but it does not induce sleep. (Drugs that induce sleep are known as hypnotics.) A drug may act as a sedative in small amounts and as a hypnotic in large amounts.
  • sedentary [sed′ n-tar″e] of inactive habits.
  • sedge numerous aquatic plants including Carex vulpina, Schoenus spp.
  • sediment [sed′ľ-m nt] a deposit, often a precipitate, that develops spontaneously.

    • s. activity test older test of ruminal function based on the speed with which the sediment in a sample of rumen fluid floats to the top, an indication that it has been digested.
  • sedimentation [sed″ľ-m n-ta′sh n] the settling out of sediment.

    • s. rate the rate at which a sediment is deposited in a given volume of solution, especially when subjected to the action of a centrifuge. The erythrocyte sedimentation rate is the rate at which erythrocytes settle out of unclotted blood. Abbreviated sed. rate or ESR. The test is based on the fact that inflammatory processes cause an alteration in blood proteins, resulting in aggregation of the red cells, which makes them heavier and more likely to fall rapidly when placed in a special vertical test tube. Normal ranges vary according to the type of tube used, each type being of a different size, and with the species, horse erythrocytes falling faster than those of other species.
  • seed [sēd] 1. the mature ovule of a flowering plant. 2. semen. 3. a small cylindrical shell of gold or other suitable material, used in application of radiation therapy. 4. to inoculate a culture medium with microorganisms.

    • s. dressing chemicals mixed with seed grain to prevent infestation with insects and rodents and infection by fungi. Most are poisonous to animals and deaths may occur if the grain is not used as seed and is put back into the animal feed chain. The amount of feed in a collection of seed is usually very large, and the probability is that it would be fed without dilution that would reduce its toxicity. Grain or grain products are also used as bait for birds, or to repel birds and to poison snails and other garden pests, and all of them may be accessible to animals.
    • s. mixtures mixtures of small grass and cereal seeds used as feed for companion birds. Some of the seeds used are the millets, chopped oat groats, canary grass (Phalaris spp.) seed, sunflower seed, hemp seed, rape seed.
    • radon s. a small sealed container for radon, for insertion into the tissues of the body in radiotherapy.
  • seeding the plaques of hard tissue in the subcutaneous tissue in the floor of the udder of some recently calved cows. The milk is normal, and the plaques disappear within a few days, sooner if they are massaged and hot fomented. Called also caking.
  • seedy cut belly tissue in a pig carcass, including mammary gland, which is streaked with melanin.

    S-38.

    

    Seedy toe in a horse’s hoof.

  • seedy toe a defect in the wall of the hoof of the horse, seen best from the sole. The inner part of the wall is crumbly and soft and is easily picked out. The defect extends up behind the wall sometimes as far as the coronet. Called also hollow wall, dystrophia ungulae.
  • seeing practice the activity in which an undergraduate veterinary student accompanies a practicing veterinarian and receives in-service training. In North America called externship.
  • seeker a probe or sound; a long thin rod used to probe the opening or a tract or a cavity in order to determine its direction, source, or depth.
  • segment [seg′m nt] a demarcated portion of a whole.

    • bronchopulmonary s. one of the smaller subdivisions of the lobe of a lung, sometimes separated from others by a connective tissue septum and supplied by its own branch of the bronchus leading to the particular lobe.
    • hepatic s’s subdivisions of the hepatic lobes based on arterial and biliary supply and venous drainage.
  • segmental [s g-men′t l] pertaining to a segment or to segmentation. See also segmental aplasia, axonopathy, cerebellar atrophy, myelitis.
  • segmentation [seg″m n-ta′sh n] 1. division into similar parts. 2. cleavage.

    • intestinal s. periodic constriction of segments of intestine without movement backward or forward; a mixing rather than a propulsive movement; the movements are reflex and can be initiated by intrinsic nerves in the wall of the small intestine.
  • segmenter [seg′m n-t r] a segmented neutrophil.
  • segregation [seg″r -ga′sh n] the separation of allelic genes during meiosis as homologous chromosomes begin to migrate toward opposite poles of the cell, so that eventually the members of each pair of allelic genes go to separate gametes.

    • adjacent s. during meiosis adjacent centromeres segregate together.
    • alternate s. when diagonally opposite centromeres segregate together.
  • segregator [seg′r -ga′t r] an instrument for obtaining the urine from the ureter of each kidney separately.
  • Segugio Italiano a medium-size, lightly built hunting dog with an elongated, narrow head, deep chest, and thin tail that is carried high. The coat is black and tan of any shade, with white markings. There are two varieties: coarsehaired and shorthaired. Called also Italian hound. A breed recognized by the Kennel Club UK.
  • seismotherapy treatment of disease by mechanical vibration. Extracorporeal shockwave therapy (ESWT) may be considered a specific type of seismotherapy that uses short, high-amplitude pulses of mechanical energy.
  • Seitz filter a filter made of compressed asbestos fibers used in microbiological work to sterilize fluids such as serum and to filter off bacteria but permit the passage of viruses.
  • seizure [se′zh r] 1. the sudden attack or recurrence of a disease. 2. a paroxysmal transient disturbance of nervous system function resulting from uncontrolled electrical discharges from neurons within the prosencephalon. In animals, seizures may be obvious if the neuronal discharges affect regions of the brain that control motor activity, consciousness, behavior, emotion, vision or hearing. Such signs include episodic impairment or loss of consciousness, abnormal motor phenomena (also known as convulsions), psychic, or sensory disturbances or perturbation of the autonomic nervous system. In humans, nonconvulsive seizures occasionally also occur in which electrical discharges occur with no obvious external signs. In both animals and people, several classification schemes have been used to describe seizure types, which include generalized, partial, and psychomotor forms, among others.

    S-39.

    

    Segmentation movements of the small intestine.

    • audiogenic s. a seizure brought on by sound.
    • cluster s’s. more than one seizure occurring within a 24-hour period.
    • flybiting s. see psychomotor seizure (below).
    • focal s. one restricted to a particular region of the brain; signs correspond to the area affected, e.g., motor activity of an isolated area or limb. Focal seizures may be either simple, if no disturbance of consciousness is noted, or complex, if motor signs are accompanied by a disturbance of consciousness. Focal seizures may also undergo secondary generalization during which the electrical disturbance spreads to involve the entire prosencephalon. Called also partial seizures, petit-mal seizures.
    • generalized s. a seizure involving the entire prosencephalon from its onset. During a generalized seizure there are no clinical signs indicating an origin or focus, and there is a loss of or disturbance of consciousness. Generalized seizures are divided into those with motor signs (generalized tonic seizures, generalized clonic seizures, generalized tonic-clonic seizures, atonic seizures) and those with loss of consciousness only (absence seizures).
    • generalized tonic-clonic s. one with no localizing signs. Commonly involves several phases: aura, preictal phase, ictus, and postictal phase. During the ictus there is loss of consciousness, generalized muscular activity, excessive salivation, chewing activity, opisthotonos, running movements, and often urination and defecation. The postictal phase may last from several minutes to hours or even days, during which signs of prosencephalic disturbance continue, with signs including blindness, manic behaviour, and behavioral changes. Generalized tonic-clonic seizures are the most common type of seizure in dogs and cats. Called also grand mal seizures.
    • grand mal s. see generalized tonic-clonic seizure (above).
    • jacksonian s. see jacksonian seizures.
    • marching s. see jacksonian seizures.
    • partial s. see focal seizure (above).
    • petit mal s. see focal seizure (above), petit mal.
    • photogenic s. a seizure brought on by light.
    • psychomotor s. motor seizures accompanied by behavioral changes but without apparent impairment of consciousness. A common manifestation in dogs, commonly referred to as flybiting seizures; involves biting motions, accompanied by apparent visual hallucinations. The animal appears to be ‘snapping’ at an invisible object. Other phenomena may include hallucinations, salivation, pupillary dilatation, mastication, fecal and urinary excretion, and wild running. Such seizures may be seen in dogs with lesions in the pyriform lobe or hippocampus and from poisoning with agenized flour (canine hysteria). They have also been suggested to have an origin in the temporal lobe due to the relatively common occurrence of visual and auditory hallucinations reported by human patients with temporal lobe epilepsy. Called also running fits.
    • tetanic s. see tetany.
    • s. threshold the level of stimulation at which a seizure is precipitated.
    • tonic s. one in which the muscles are rigid.
    • tonic–clonic s. alternating tonic (rigid muscles) and clonic (jerking of muscles) phases; a grand mal seizure.
  • selamectin a semisynthetic avermectin effective against internal and external parasites. Applied topically is used for the prevention of heartworms and control of fleas and mites in dogs and cats, ticks in dogs, and hookworms and roundworms in cats.
  • Seldinger technique is employed to safely insert over-the-wire catheters, probes, electrodes, etc., into vessels. A needle is inserted first, then a guidewire is passed through, and the needle removed. The catheter is then passed over the wire
  • selectins [s -lek′tin] a family of cell adhesion molecules found on endothelial cells, leukocytes, and platelets that bind oligosaccharides on other cells tightly and specifically, and are involved in signal transduction across the plasma membrane.
  • selection [s -lek′sh n] 1. choosing the individual units to be included in a sample. See also random selection. 2. choosing the animals to be retained for breeding purposes; genetic selection.

    • artificial s. selection based on human decisions.
    • s. coefficient proportionate reduction in the average genetic contribution made by a specific genotype, relative to the contribution made by another genotype. Denoted by s, the selection coefficient is a measure of the relative fitness of a phenotype
    • s. criteria the animal characteristic that is used in a selection program.
    • s. differential a measure of the gain achieved by selection; the phenotypic superiority of selected individuals, compared to the population from which they were selected.
    • family s. selection of individuals to be used in a breeding program based on the merits of sibs or half sibs.
    • s. index a single overall estimate of the animal’s true breeding value obtained from as many sources of information as are available.
    • individual s. selection on the results of performance testing of the subject.
    • s. intensity the superiority of the individuals selected for breeding, relative to the population from which they were selected.
    • s. limit the situation in which the entire population is homozygous for the same set of favorable genes; called also selection plateau.
    • s./mutation balance when the rate of removal of a gene from the population by selection equals the rate at which mutations occur.
    • natural s. selection occurring in nature, without any human intervention, direct or indirect.
    • s. plateau see selection limit.
    • s. program the method used to select individuals from a population to be used for breeding. Usually includes nomination of the traits to be selected, the optimum size of the population in which the program is to operate, the intensity of selection available, the accuracy of the selection procedures, lengths of the generations in the species, the target rate of response.
  • selective [s -lek′tiv] the use of procedures on selected animals contrasted with blanket application to all members of the group.
  • selectivity [s -lek-tiv′ľ-te] 1. the accuracy of a test in identifying animals that have the disease that is under investigation; the number of false positives to the test will be low in a selective test. 2. in pharmacology, the degree to which a dose of a drug produces the desired effect in relation to adverse effects.
  • selector plant see indicator plants.
  • selegiline [s -lej′ -lēn] see l-deprenyl.
  • selenates injectable forms of selenium; examples are sodium selenate and slow release barium selenate.
  • seleniferous [se″l -nif′ r-us] rich in selenium.
  • selenite broth an enrichment broth for the growth of salmonellae.
  • selenium (Se) [s -le′ne- m] a chemical element, atomic number 34, atomic weight 78.96. It is an essential mineral nutrient and a very potent poison. A major function of selenium is its role in the seleniumcontaining enzyme glutathione peroxidase, an antioxidant enzyme that protects against free-radical and oxidative damage.

    • s.-75 (⁷⁵Se) a radioisotope of selenium having a half-life of 120 days and a principal gamma ray photon energy of 265 keV; used in the radiopharmaceutical selenomethionine.
    • s. accumulator plants see accumulator plants.
    • s. converter plants see converter plants.
    • s. food supplements include selenomethionine, sodium selenite, sodium selenate, selenium yeast, or protein or amino acid chelated forms.
    • s. indicator plants see indicator plants.
    • s.-induced infection resistance selenium deficiency in the diet may increase the patient’s susceptibility to infection.
    • s. nutritional deficiency there are well-defined diseases caused by selenium deficiency and poorly defined selenium responsive diseases. A nutritional deficiency of vitamin E has many of the same effects of selenium deficiency, and it is often difficult to separate the two. Selenium deficiency is associated with impaired immune function and the prevalence of disease problems such as mastitis and postpartum reproductive disorders in dairy herds can be reduced in selenium deficient herds by selenium supplementation. See also enzootic muscular dystrophy, mulberry heart disease, hepatosis dietetica, iron poisoning, weaner illthrift.
    • s. poisoning can occur on pasture growing on selenium rich soil, especially if there are selenium indicator plants growing in it. Also when selenium supplementation is carried out carelessly, and there is accidental access to poisonous amounts. Acute poisoning features diarrhea, dyspnea, and death. So-called ‘blind staggers’ in North America, once erroneously attributed to selenium poisoning, are now known to result mostly from sulfur-associated polioencephalomalacia. Chronic poisoning produces a syndrome of stiff gait, loss of haircoat, and separation, perhaps sloughing, of the hooves. Called also alkali disease.
    • s.-responsive diseases diseases such as reproductive inefficiency and illthrift in sheep and cattle, retained placenta, mastitis in cattle respond in some situations to dietary supplementation with selenium but the diseases are not proven to be caused by nutritional deficiency of the element.
    • s. sulfide, s. disulfide a commonly used keratolytic in medicated shampoos employed in the treatment of skin disease in dogs and cats.
    • s. weed see Neptunia amplexicaulis.
  • seleno-DL-methionine methionine with selenium bonded to the terminal methyl group. A common source of selenium in the diet.

    S-40.

    

    Selenium poisoning. Separation of coronary band with slippering of hoof.

  • selenocompounds organic compounds containing selenium; found in plants and providing the medium by which selenium poisoning occurs via the ingestion of unpolluted plants.
  • selenodont [s -le′no-dont] molar teeth with crescent-shaped cusps, a characteristic of ruminant herbivores.
  • Selenomonas ruminantium [se″le-no-mo′nas] bacterial resident of the rumen; participates in fermentation, and hence digestion, of plant ingesta.
  • selenosis [se″le-no′sis] see selenium poisoning.
  • self [self] a term used to denote an animal’s own antigenic constituents, in contrast to ‘not-self’, denoting foreign antigenic constituents. The ‘self’ constituents do not normally elicit an immune response, i.e., there is self-tolerance, whereas the antigens that are ‘not-self’ do elicit an immune response. In the process of lymphocyte maturation, self-reactive lymphocytes, particularly T lymphocytes within the thymus, are eliminated. The breakdown of self-tolerance by a number of mechanisms is the basis for autoimmune diseases. See also immunity.
  • self-antigen [self-an′tľ-j n] any constituent of the body’s own tissues capable of stimulating autoimmunity. See also immunity.
  • self-colored whole-colored.
  • self-contained cleaning system an abattoir cleaning unit containing all of the necessary functions including cleaning, application of live steam, or a disinfectant.
  • self-cure a phenomenon in sheep in which a hypersensitivity to an adult worm load develops, and the worms are discharged. The hypersensitivity is induced by a second larval infestation. The apparent ‘cure’ of the sheep can be clinically significant and can be misleading in the assessment of a control program.
  • self-feeder a feed container from which animals can take feed at will, but that is protected against weather, and wastage by scattering is minimal. Carbohydrate engorgement can occur if the livestock are not used to the system and eat too much grain. Dogs on such a system may overeat and become obese.
  • self-limited [self-lim′it- d] limited by its own peculiarities, and not by outside influence; said of a disease that runs a definite limited course and resolves itself without intervention.
  • self-mutilation the animal damages itself by biting or by violent and persistent scratching or rubbing, e.g., cattle with pseudorabies, sheep with pseudorabies. A degree of injury beyond self-trauma.
  • self-nursing see self-sucking.
  • self-recognition see self.
  • self-replicating elements include plasmids, episomes, and transposons.
  • self-selection a circumstance in which the allocation of units of a population to one or other of two groups that are to be compared is done by the units, e.g., the sick animals in one group, the not-sick in the other. See also volunteer sample.
  • self-sucking a vice in which a female animal sucks her own milk. Seen in cows, bitches, and queens.
  • self-tolerance [self-tol′ r- ns] immunological tolerance to self-antigens.
  • self-trauma self-inflicted injury, usually to the skin and hair coat, caused by an animal’s response to pruritus. Depending on the species, this can be scratching, biting, pecking, licking, rubbing, or rolling. See also scratching (1).
  • Selkirk rex a new breed of cat derived from a cat with a dominant mutation that produces curly hair. The breed is medium to large, heavy boned and can have short or long hair in any color. See also Rex.
  • sella [sel′ ] pl. sellae [L.] a saddle-shaped depression.

    • empty s. a syndrome in which the pituitary fossa appears to be empty but the pituitary gland is present in a flattened form.
    • s. turcica a depression on the upper surface of the sphenoid bone within which is a deep depression that lodges the pituitary gland.
  • Sellick maneuver [sel′ik] compression of the esophagus against the cricoid cartilage to occlude the esophageal lumen and avoid regurgitation during induction of anesthesia.
  • SEM 1. scanning electron microscope. 2. standard error of the mean.
  • semduramicin a fermentation product of Actinomadura roseorufa used for the prevention of coccidiosis in chickens.
  • semeiography a description of the clinical signs of a disease.
  • semeiology [se″me-ol′ -je] symptoms or signs of disease.
  • semeiotic [se″me-ot′ik] 1. pertaining to clinical signs. 2. pathognomonic.
  • semelparity a reproductive pattern of organisms in which there is reproduction only once in a lifetime, e.g., annual plants and Antechinus spp.
  • semen [se′m n] fluid discharged at ejaculation in the male, consisting of spermatozoa in their nutrient plasma, secretions from the prostate, vesicular glands (seminal vesicles) and various other glands, epithelial cells and minor constituents.

    • s. collection for artificial insemination or laboratory evaluation or examination in a clinicopathological sense. Done by artificial vagina, electroejaculation, genital massage or chemical means.
    • s. concentration the number of spermatozoa per ml in the ejaculate.
    • s. diluent there are a number of suitable diluents with some preference being given to one or other of them in each species. There are also different diluters for chilled liquid semen as distinct from frozen semen. Most diluters are based on biological fluids such as whole or skim milk, buttermilk, cream and egg yolk. The general cryoprotectant for freezing is glycerol. Called also semen extender.
    • s. evaluation laboratory process of determining semen quality by measuring sperm concentration, motility, morphology and other parameters.
    • s. extender see semen diluent (above).
    • frozen s. semen stored in liquid nitrogen at −196°C (−321°F).
    • s. nonsperm portion see semen presperm fraction (below).
    • s. presperm fraction the accessory gland fluid emitted at the beginning of ejaculation.
    • s. samples part of an ejaculate collected for laboratory examination.
    • s. sperm-rich fraction the portion of the ejaculate containing most of the spermatozoa.
    • s. stones concretions of amorphous cellular debris and clumps of nuclear material found in vesicular glands (seminal vesicles) of bulls.
    • s. storage chilled bull semen stored at 5°C can be stored and used for 5 days; frozen bull semen (−79°C using dry ice or −196°C using liquid nitrogen) can be stored and used successfully for up to 10 years, with only a small drop in fertility after 40 years.
  • semi- word element. [L.] half.
  • semiarid said of regions of the earth that have dry climates but not as dry as those of arid climates.
  • semicanal [sem″e-k -nal′] a channel open at one side.
  • semicircular shaped like a half-circle.

    • s. canals the passages in the inner ear, in the bony labyrinth concerned with the sense of balance, especially the detection of movement. Each ear has three semicircular canals (anterior, lateral and posterior) situated approximately at right angles to each other. They contain the semicircular ducts.
    • s. ducts the membranous tubes housed within the semicircular canals. They have enlarged portions at one end, called ampullae, which contain nerve endings and which are filled with fluid. The semicircular ducts respond to movement of the head. When the head changes position, the fluid in the duct that lies in the plane of movement also moves but, because of its inertia, the fluid flow lags behind the head movement. Thus the fluid presses against the delicate hairs of the nerves in the ampulla, and these nerves then register the fact that the head is turning in such a direction. It is the fluid movement in the semicircular ducts that causes the feeling of dizziness or vertigo after spinning. When the spinning stops, the fluid in the horizontal canal continues to move for a moment in the direction of the spin, giving a temporary false reading that the head is turning in the other direction. Motion sickness is caused by the unusual and erratic motions of the head in an airplane, car or ship, and the resulting stimulation of the semicircular ducts. Many animals, even fish, can experience motion sickness.

      S-41.

      

      Semicircular canals of the ear, showing locations of ampullae.

  • semicoma [sem″e-ko′m ] a stupor from which the animal may be aroused.
  • semiconsciousness see semicoma.
  • semiflexion [sem″e-flek′sh n] the position of a limb midway between flexion and extension; the act of bringing to such a position.
  • semihairlessness an autosomal recessive trait in Hereford and polled Hereford cattle; affected calves are born with a thin, curly haircoat, and some fail to thrive.
  • semilunar [sem″e-loo′n r] shaped like a half-moon or crescent.

    • s. valve valves of the aorta (aortic valve) and pulmonary trunk (pulmonary valve) where they leave the left and right cardiac ventricles, respectively.
    • s. valve anomaly abnormal development causes an irregular central perforation of the valve and the signs of valvular stenosis.
  • seminal [sem′ľ-n l] emanating from or pertaining to semen.

    • s. colliculus see seminal colliculus.
    • s. fluid some of the fluid originates in the testis but most is contributed by the various sex glands, the amount and the composition from each gland varying between species.
    • s. glands see vesicular glands.
    • s. peritonitis peritonitis caused by rupture of the vagina by the stallion during mating, or of the cow’s uterus by the inseminator; causes a low-grade, chronic peritonitis in the caudal abdomen.
    • s. plasma the liquid supernatant after sedimentation or centrifugation of semen.
    • s. vesicle see vesicular glands.
    • s. vesiculitis see vesicular adenitis.
  • semination [sem″ľ-na′sh n] insemination.
  • seminiferous [sem″ľ-nif′ r- s] producing or carrying semen.

    • s. tubule develop as hollow tubes in the testis after birth, from solid gonadal cores.
  • seminin a proteolytic enzyme of human semen.
  • seminoma [sem″ľ-no′m ] tumor of the testis thought to arise from basal spermatogonia. They are common in older dogs and occur often in cryptorchid testes. Seminomas also occur in the male of other domestic species.
  • seminoperitoneum see seminal peritonitis.
  • seminuria [se′mľ-nu′re- ] discharge of semen in the urine.
  • semipermeable [sem″e-pur′me- -b l] permitting passage only of certain molecules; said of a membrane.
  • semiplacenta diffusa see adventitial placentation.
  • semiquantitative [sem″e-kwahn′tľ-ta″tiv] yielding an approximation of the quantity or amount of a substance; falling short of a quantitative result.
  • semis (ss.) [se′mis] [L.] half or one-half.
  • semisulcus [sem″e-sul′k s] a depression that, with an adjoining one, forms a sulcus.
  • semisupination [sem″e-soo″pľ-na′sh n] a position halfway toward supination.
  • semisynthetic [sem″e-sin-thet′ik] produced by chemical manipulation of naturally occurring substances.
  • semitendinosus muscle in the hamstring group of muscles; extend the hip joint and flex the stifle; see Table 12.4.
  • Semitic fat-tailed sheep see Near East fat-tailed.
  • Semkin forceps thumb-operated, very fine-pointed, tissue forceps for pediatric work.
  • Semliki forest virus [sem-le′ke] an alphavirus associated with illness in humans and other animals in Africa.
  • Sendai virus a paramyxovirus that causes a highly contagious disease of the respiratory tract of mice in which there is pneumonia and a high mortality rate in the young. It also infects rats but is usually subclinical.
  • senecavirus A (SV-A) positive-sense single-stranded RNA virus that belongs to the Senecavirus genus within the Picornaviridae family; known previously as Seneca valley virus.
  • senecavirus-A vesicular disease an emerging vesicular disease in swine, recently reported in North and South America, China, and Asia, characterized by lameness, coronary band hyperemia, and vesicles on the snout and coronary bands. In addition, SV-A has been associated with neonatal mortality in piglets. Lesions are clinically indistinguishable from other vesicular viruses infections, including foot-and-mouth disease virus, vesicular stomatitis virus, and swine vesicular disease.
  • Senecio [s -ne′she-o] a widespread genus of the Asteraceae family. The genus contains more than 1200 species, of which at least 25 are known to be poisonous. The toxins are a group of pyrrolizidine alkaloids that cause seneciosis hepatic injury, and the dummy syndrome, jaundice, emaciation, and photosensitization.
  • senecionine hepatotoxic pyrrolizidine alkaloid found in Senecio spp. and Crotalaria spp.
  • seneciosis [s -ne″she-o′sis] acute or chronic hepatic insufficiency caused by the ingestion of pyrrolizidine alkaloids in Senecio. Characterized by a syndrome of jaundice and central nervous system derangement and possible photosensitization. Most outbreaks occur in animals on pasture but housed animals fed hay that is contaminated by the foliage or seeds can be affected. Called also Molteno disease, Pictou disease, Schweinsberger disease, Winton disease.
  • senescence [se-nes′ ns] depression of body functions as part of the process of growing old.
  • senile [se′nīl] pertaining to old age; manifesting senility.
  • Senn retractor a handheld instrument with a curled, three-pronged claw at one end and a right-angled, single blade at the other. Suitable for short-term displacement of soft tissue.
  • Senna [sen′ ] plant genus in the legume family Caesalpiniaceae; contain anthraquinone glycosides that cause diarrhea; an unidentified toxin in some causes muscle necrosis of striated muscles leading to myoglobinuria and sudden death. Includes S. floribunda, S. obtusifolia (Javabean, sicklepod), S. occidentale (coffee senna, wild coffee), S. roemeriana. All previously classified in the genus Cassia.

    S-42.

    

    Senecio jacobea (ragwort).

    S-43.

    

    Senn rake retractor.

  • senna [sen′ ] 1. common name for some plants in the genera Senna and Cassia. Includes senna or coffee bean (S. occidentalis), smooth senna (S. floribunda), twin-leaf senna (S. roemeriana). 2. the dried leaflets of Cassia acutiflora; used in a syrup, fluid extract, or compound powder as a cathartic.
  • Sennenhund the type of working dogs known as Swiss mountain dogs with four regional types generally recognized as separate breeds although not in all countries. Includes Greater Swiss mountain dog, Bernese mountain dog, Entlebucher mountain dog, and the Appenzeller. Off varying sizes, all have a characteristic tricolor coat.
  • sensation [sen-sa′sh n] an impression produced by impulses conveyed by an afferent nerve to the sensorium. Includes cold, distention, hunger, itch, pain, taste of various kinds, thermal, thirst, tickle, touch, warmth, and some psychological and emotional experiences that animals obviously experience but cannot describe. See also sense.

    • s. disturbance cutaneous sensation errors include paresthesia, hyperesthesia, anesthesia. See also blindness, deafness.
  • sense [sens] a faculty by which the conditions or properties of things are perceived. Hunger, thirst, malaise, and pain are varieties of sense; a sense of equilibrium or of well-being (euphoria), and other senses are also distinguished. The five major senses comprise vision, hearing, smell (2), taste, and touch (1). The operation of all senses involves the reception of stimuli by sense organs. Each sense organ is sensitive to a particular kind of stimulus. The eyes are sensitive to light; the ears, to sound; the olfactory organs of the nose, to odor; and the taste buds of the tongue, to taste. Various sense organs of the skin and other tissues are sensitive to touch, pain, temperature, and other sensations. On receiving stimuli, the sense organ translates them into nerve impulses that are transmitted along the sensory nerves to the brain. In the cerebral cortex, the impulses are interpreted, or perceived, as sensations. The brain associates them with other information, acts upon them, and stores them as memory. See also sensation.

    • common chemical s. mediated by the trigeminal nerve from chemical sense organs in the conjunctival sac and in the nasal and buccal cavities.
    • cutaneous s. skin senses including touch, pressure, pain, heat, and cold.
    • s. organs 1. the organs of special sense including eye, olfactory organ, gustatory organs. 2. all organs containing sensory receptors.
    • special s’s the five senses including feeling, hearing, seeing, smelling, tasting.
    • s. strand see coding strand.
  • sensibility [sen″sľ-bil′ľ-te] susceptibility of feeling; ability to feel or perceive.

    • deep s. the sensibility of deep tissue (muscle, tendon, etc.) to pressure, pain, and movement.
    • epicritic s. the sensibility to gentle stimulations permitting fine discriminations of touch and temperature, localized in the skin.
    • proprioceptive s. the sensibility afforded by receptors in muscles, joints, and other parts, by which one is made aware of their position and state.
    • protopathic s. the sensibility to strong stimulations of pain and temperature; it is low in degree and poorly localized, existing in the skin and in the viscera, and acting as a defensive agency against pathological changes in the tissues.
    • somatesthetic s. proprioceptive sensibility.
    • splanchnesthetic s. the sensibility to stimuli received by splanchnic receptors.
  • sensible [sen′sľ-b l] perceptible to the senses; capable of sensation.
  • sensitive [sen′sľ-tiv] 1. able to receive or respond to stimuli. 2. unusually responsive to stimulation, or responding quickly and acutely.

    • s. vessel syndrome temporary engorgement of conjunctival blood vessels in the absence of disease. Seen most commonly in small dogs and cats.
  • sensitive plant Mimosapudica.

    • giant s.p. Mimosainvisa.
  • sensitivity [sen″sľ-tiv′ľ-te] the state or quality of being sensitive. the probability that a test will indicate ‘disease’ among those with the disease

    • antibiotic s., antimicrobial s. the degree of susceptibility of a bacterial isolate to individual antimicrobial drugs. Measured by growth in liquid culture media with serial dilutions of the antimicrobial, or on agar plates as measured by the width of the zone of growth inhibition around a disk impregnated with the antimicrobial.
    • bacterial s. see antibiotic sensitivity (above).
    • contact s. see contact hypersensitivity.
    • diagnostic test s. the probability that a test will correctly identify the patients that are infected or have a specified noninfectious condition. A fundamental parameter for all diagnostic tests. A sensitive test will pick up the minutest quantity of antibody or other agent in a biological fluid. There are times when this is a desirable characteristic but the loss of specificity that usually accompanies the high sensitivity, needs to be taken into account. See also specificity.
    • light s. see photosensitization.
    • radioimmunoassay s. the smallest amount of hormone that the assay can accurately detect above a zero amount.
  • sensitization [sen″sľ-tľ-za′sh n] a state in which the body is sensitized to particular stimuli, e.g., (1) certain individuals exposed to some antigens by a particular route elicit an immune response that may be antibody-mediated, particularly IgE, or cell-mediated, which sensitizes them such that subsequent exposure to the same antigen elicits an allergic response; said especially of such exposure resulting in a hypersensitivity reaction. (2) The coating of cells with antibody as a preparatory step to some detectable reaction such as their lysis if complement is added. (3) The preparation of a tissue or organ by one hormone so that it will respond functionally to the action of another.

    • active s. the sensitization that results from the injection, ingestion, or inhalation, of antigen into the animal. See also active immunity, active immunization.
    • passive s. that which results when blood serum from a sensitized animal is injected into a normal animal. See also passive immunity, passive immunization.
    • protein s. that bodily state in which the individual is sensitive or hypersusceptible to some foreign protein, so that when there is absorption of that protein a typical allergic reaction is set up.
  • sensitized [sen′sľ-tīzd] rendered sensitive.

    • s. cells see sensitization (2).
  • sensitizer [sen′sľ-ti″z r] see antigen.
  • sensitogen a substance that can evoke hypersensitivity.
  • sensomobile moving in response to a stimulus.
  • sensomotor [sen″so-mo′t r] sensorimotor.
  • sensor [sen′s r] a device, usually electronic, which detects a variable quantity and measures and converts the measurement into a signal to be recorded elsewhere.
  • sensorial [sen-sor′e- l] pertaining to the sensorium.
  • sensorimotor [sen″s -re-mo′t r] both sensory and motor.

    • s. plegia loss of sensory and motor function caudal to the level of a spinal cord injury.
  • sensorineural [sen″s -re-noor′ l] of or pertaining to a sensory nerve or sensory mechanism, as sensorineural deafness.
  • sensorium [s n-sor′e- m] 1. the part of the cerebral cortex that receives and coordinates all the impulses sent to individual nerve centers. 2. the state of an individual as regard consciousness or mental awareness.

    S-44.

    

    Agar plate antibiotic sensitivity test.

    • s. commune the part of the cerebral cortex that receives and coordinates all the impulses sent to individual nerve centers. Includes auditory, gustatory, olfactory, somatosensory, and visual centers.
  • sensory [sen′s -re] pertaining to sensation.

    • s. input produced by sensory organs and transmitted by afferent nerve fibers to the central nervous system. See also sense.
    • s. perceptivity the ability to perceive, to feel. Tests for this in animals are based on the assumption that the observer can differentiate between a reflex response and a central perception.
  • sentient [sen′she- nt] able to feel; sensitive.

    • s. being the name proposed by animal activists for pets and other animals. It implies that animals have a human-like capacity for thinking, feeling, and understanding. Its use could have implications in animal law.
  • sentinel [sen′tľ-n l] a recording mechanism, such as an animal, a farm or a veterinarian, posted explicitly to record a possible occurrence or series of occurrences in a prospective surveillance program. For example, periodic serological surveillance of sentinel herds and flocks is a common strategy for monitoring the incursion or spread of a disease.

    • s. loop a distended loop of small intestine visible on an abdominal radiograph; may indicate severe local inflammation e.g., with acute pancreatitis, or mechanical obstruction of the bowel.
  • sentry dog one trained for guard duty, particularly as used by the military for patrolling perimeter fences.
  • separation anxiety [sep″ -ra′sh n] in companion animals a state of panic caused by the absence of the owner. Often manifest with restlessness and vocalization and possibly with destructive behavior and house soiling.
  • separation from group [sep″ -ra′sh n] sick animals, frightened animals may separate themselves from the group.
  • sepsis [sep′sis] the presence in the blood or other tissues of pathogenic microorganisms or their toxins; the condition associated with such presence. See also toxemia, bacteremia.

    • puerperal s. sepsis occurring after parturition. See also mastitis–metritis–agalactia.
  • septa [sep′t ] plural of septum.
  • septal [sep′t l] pertaining to a septum.

    • s. defect see ventricular septal defect, aortic septal defect, atrial septal defect.
  • septan recurring on the seventh day (every 6 days).
  • septate [sep′tāt] divided by a septum or septa.
  • septectomy [s p-tek′t -me] excision of part of a septum such as the nasal septum.
  • septic [sep′tik] pertaining to sepsis.

    • s. fever is fever associated with infection either as local abscess or cellulitis or as a septicemia or bacteremia. The infective agent may be a bacteria, virus, fungus, protozoa, or even algae.
    • s. mastitis mastitis characterized by the presence of bacteria in the milk.
    • s. shock see toxemic shock.
  • septicaemic septicemic.
  • septicemia [sep″tľ-se′me- ] systemic disease associated with the presence and persistence of pathogenic microorganisms and their toxins in the blood. The resulting syndrome is a combination of the signs of toxemia and hyperthermia, i.e., fever, mucosal and conjunctival petechiation, and evidence of localization in joints, eyes, meninges, heart valves. Proof is by positive blood culture or smear. See also specific infections, e.g., anthrax, pasteurellosis, colibacillosis. Called also blood poisoning.

    • bacterial hemorrhagic s. includes many bacterial diseases of fish, e.g., vibriosis, but usually refers to systemic infection by opportunists such as Aeromonas hydrophila, Pseudomonas spp.
    • cryptogenic s. septicemia in which the focus of infection is not evident during life.
    • enteric s. an important disease in catfish aquaculture; hemorrhages and white focal lesions occur on the skin and in the liver, and there is hemorrhagic enteritis; in another form, there is a septic meningitis. Caused by Edwardsiella ictaluri.
    • foal s. rapidly fatal septicemia of the newborn foal caused by Actinobacillus equuli, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, β-hemolytic streptococcus.
    • hemorrhagic s. septicemia characterized by marked petechiation on mucosae and serosae. Also used as a specific name for septicemic pasteurellosis in cattle; see hemorrhagic septicemia.
    • puerperal s. that in which the focus of infection is a lesion of the mucous membrane received during parturition.
    • puppy s. puppies normal at birth, weaken and die after the first 24 hours. The usual causes are infection by hemolytic streptococci, Escherichia coli and Brucella canis.
  • septicemic [sep″tľ-se′mik] emanating from or pertaining to septicemia. See also septicemic colibacillosis, leptospirosis, listeriosis, pasteurellosis, salmonellosis.

    • s. cutaneous ulcerative disease (SCUD) generalized infection of the shell in chelonians. Often caused by Citrobacter freundii, Pseudomonas spp., or Aeromonas. spp. Frequently associated with poor nutrition and husbandry, also known as ‘shell rot’.
  • septicophlebitis septicemic inflammation of veins.
  • septicopyemia [sep″tľ-ko-pi-e′me- ] septicemia with pyemia.
  • septicweed Sennaoccidentalis.
  • septomarginal [sep″to-mahr′jľ-n l] pertaining to the margin of a septum.

    • s. trabeculae the moderator bands that stretch from the ventricular septum to the opposite wall of the ventricle. They are partly muscular and partly tendinous and function not so much ‘to moderate’, but to convey electrical impulses to the muscle of the opposite wall, thereby short-circuiting the long route via the apex of the heart. Called formally trabecula septomarginalis dextra and trabeculae septomarginales sinistrae.
  • septonasal [sep″to-na′z l] pertaining to the nasal septum.
  • septoplasty [sep′to-plas″te] surgical reconstruction of a septum, usually referring to the nasal septum.
  • septostomy [sep-tos′t -me] surgical creation of an opening in a septum.
  • septotomy [sep-tot′ -me] incision of the nasal septum.
  • septula testis [sep′tu-l ] septa of connective tissue and plain muscle in the testis, subdividing it into lobules.
  • septulum [sep′tu-l m] pl. septula [L.] a small separating wall or partition.
  • septum [sep′t m] pl. septa [L.] a wall or partition dividing a body space or cavity. Some septa are membranous, some are composed of bone, and some of cartilage. They are usually named according to their location.

    • atrioventricular s. the part of the membranous portion of the interventricular septum between the left ventricle and the right atrium.
    • bulbar s. a septum, formed by merging of the bulbar cushions, divides the bulbus cordis into aortic and pulmonary outflows.
    • cystic s. pellucidum an embryonic malformation resulting in the formation of a fluid-filled cavity in the septum between the two lateral ventricles, instead of the normal glial raphe.
    • horizontal s. in the avian body cavity, there is no diaphragm but the body cavity is divided into three compartments; the horizontal septum is one of the divider organs; thin and membranous for the most part, the septum forms the ventral boundary of paired cavities containing the lungs.
    • interalveolar s. the bony partition between adjacent tooth sockets.
    • interatrial s. the partition separating the right and left atria of the heart.
    • interlobar s. a septum that converts an organ into lobes.
    • intermuscular s. fascial septum separating muscle masses.
    • interorbital s. bony partition between the large orbital cavities of birds.
    • interventricular s. the partition separating the right and left ventricles of the heart. See also ventricular septum.
    • s. lucidum septum pellucidum (below).
    • median s. membranous partition in the ventral median fissure of the spinal cord.
    • oblique s. a partition that divides the lower part of the bird’s body cavity; the part of the cavity cranial to this septum contains the thoracic air sacs and the thoracic parts of the cervical and clavicular air sacs. The part of the body cavity caudal to this septum contains heart, liver, spleen, gastrointestinal, urinary and reproductive tracts, and abdominal air sacs.
    • orbital s. a fold that detaches from the periorbital fascia at the orbital rim, and that leads into the tarsi, the thickened margins of the eyelids.
    • s. pellucidum, pellucid s. the triangular double membrane separating the anterior horns of the lateral ventricles of the brain. Called also septum lucidum, telencephalic septum.
    • pharyngeal s. a transitory partition between the mouth and pharynx in the embryo.
    • s. primum a septum in the embryonic heart, dividing the primitive atrium into right and left chambers.
    • rectovaginal s. the membranous partition between the rectum and vagina.
    • rectovesical s. a membranous partition separating the rectum from the prostate and urinary bladder.
    • s. secundum develops during embryonic life to contribute to the formation of the foramen ovale between the cardiac atria.
    • spiral s. the arterial partition between aorta and pulmonary trunk, formed by the fusion of the truncal, bulbar, and aorticopulmonary septa of the great vessels attached to the embryonic heart.
    • telencephalic s. see septum pellucidum (above).
    • s. transversum a major contributor to the development of the diaphragm and the liver.
    • truncal s. a partition that develops from truncal cushions within the truncus arteriosus and contributes to the separation of cardiac outflow into pulmonary and systemic circulations.
    • urorectal s. a septum that divides the urinary passages from the hindgut in the embryo by horizontally partitioning the cloaca.
  • septuplet [sep-tup′l t] one of seven offspring produced at one birth.
  • sequel [se′kw l] sequela.
  • sequela [s -kwel′] pl. sequelae [L.] a morbid condition following or occurring as a consequence of another condition or event.
  • sequence [se′kw ns] the order in which monomers occur in polymeric molecules; the order of amino acids in a polypeptide chain or of nucleotides in nucleic acid.

    • autonomously replicating s. usually plasmids that replicate independently of chromosomal DNA.
    • coding s’s sections of DNA that code for the amino acids of a protein.
    • consensus s. a sequence of nucleotides that is always present in a large set of independently determined sequences. See also box.
    • enhancer s. in DNA transcription, an upstream cis-acting DNA sequence that enhances expression of a particular gene and forms part of a complex array of upstream sequences that control gene expression.
    • expressed s’s transcribed genes as detected by cDNA sequences.
    • intervening s. see intron.
    • palindromic s. see palindrome.
    • signal s. hydrophobic amino acid sequences at the amino terminus of secretory or integrated membrane proteins that direct the protein to cell membranes, particularly endoplasmic reticulum where the proteins are modified, e.g., glycosylated, and the signal sequence is removed prior to secretion or integration of the protein into the lumen of the endoplasmic reticulum. Called also signal peptide.
  • sequencing see DNA sequencing.
  • sequential characterized by a regular sequence of additions or modifications.
  • sequester [se-kwes′t r] to detach or separate abnormally a small portion from the whole.
  • sequestrant [se-kwes′tr nt] a sequestering agent, as, for example, cholestyramine resin that binds bile acids in the intestine, thus preventing their absorption.
  • sequestration [se″kw s-tra′sh n] 1. abnormal separation of a part from a whole, as a portion of a bone by a pathological process, or a portion of the circulating blood in a specific part occurring naturally or produced by application of a tourniquet. 2. isolation of a patient.

    • feline corneal s. see corneal sequestrum.
    • pulmonary s. loss of connection of lung tissue with the bronchial tree and the pulmonary veins.
  • sequestrectomy [se″kw s-trek′t -me] excision of a sequestrum.
  • sequestrum [se-kwes′tr m] pl. sequestra [L.] a piece of dead tissue that has become separated during the process of necrosis from sound tissue; refers usually to bone, but occurs also in cornea and lung.

    • feline corneal s. see corneal sequestrum.
    • lung s. a critical feature in the epidemiology of contagious bovine pleuropneumonia; the sequestrum provides a long-term source of the causative bacteria.
  • SER smooth endoplasmic reticulum.
  • Ser serine.
  • sera [se′r ] plural of serum.
  • Sereny test a test of the invasiveness of a bacterium. The organism is inoculated into the conjunctival sac of a guinea pig; invasiveness is measured by the occurrence of a keratoconjunctivitis within 24 hours. Used particularly for strains of Escherichia coli and Listeria monocytogenes.
  • serial [se′re- l] part of a series.

    • s. homology see serial homology.
  • series [sēr′ēz] a group or succession of events, objects, or substances arranged in regular order or forming a kind of chain; in electricity, parts of a circuit connected successively end to end to form a single path for the current.

    • erythrocytic s. the succession of developing cells that ultimately culminates in the erythrocyte. The morphologically distinguishable forms are rubriblast (proerythroblast), prorubricyte (basophilic normoblast), rubricyte (polychromatophilic normoblast), metarubricyte (orthochromatic normoblast), polychromatophilic erythrocyte (reticulocyte), and erythrocyte.
    • granulocytic s. the succession of developing cells that ultimately culminates in mature granulocytes (neutrophils, eosinophils, or basophils). The morphologically distinguishable forms are myeloblast, promyelocyte (progranulocyte), myelocyte, metamyelocyte, band granulocyte, and segmented granulocyte. Stem cells are committed to become either neutrophils or eosinophils before the myelocyte stage. This may also be true for basophils.
    • lymphocytic s. the succession of developing cells that ultimately culminates in mature lymphocytes. The morphologically distinguishable forms are lymphoblast, prolymphocyte, and lymphocyte.
    • monocytic s. the succession of developing cells that ultimately culminates in the monocyte. The morphologically distinguishable forms are monoblast, promonoblast, and monocyte.
    • thrombocytic s. the succession of developing cells that ultimately culminates in platelets (thrombocytes). The morphologically distinct cell types are megakaryoblast, promegakaryocyte, and megakaryocyte, which fragment to form platelets.
  • Serin finch small passeriform bird, the origin of the domestic canary. Known as the wild canary or island canary. Called also Serinus canaria.
  • serine (Ser) [sēr′ēn] a naturally occurring amino acid.
  • Serinus a genus of birds in the finch family Fringillidae; typically with yellow plumage. Found in Europe and Africa.

    • S. canaria the Atlantic canary, island or wild canary. Domesticated form known as domesticated canary or canary, Serin finch. Popular breeds are Gloster fancy, Yorkshire, Norwich, Border fancy, lizard, Belgian fancy, and Roller. They are noted for their crisp, bell-like tone combined with warbles and trills.
  • Seriola farmed finfish genus in the family Carangidae known as amberjacks. Includes S. lalandi (yellowtail amberjacks), S. quinqueradiata (Japanese amberjack).
  • serocolitis inflammation of the tunica serosa of the colon.
  • seroconversion [sēr″o-k n-vur′zh n] the development of antibodies to an infectious organism in response to natural infection or to the administration of a vaccine.
  • seroculture [sēr′o-kul″ch r] a bacterial culture on blood serum.
  • serodiagnosis [sēr″o-di″ g-no′sis] diagnosis of disease based on serum reactions.
  • seroenteritis [sēr″o-en″t -ri′tis] inflammation of the tunica serosa of the intestine.
  • seroepidemiology [se″ro-ep″ľ-de″me-ol′ -je] a system of epidemiological surveillance and examination based on mass and serial testing of sera of samples of the animal populations.
  • serofibrinous [sēr″o-fi′brin- s] marked by both a serous exudate and precipitation of fibrin.
  • serological [sēr″o-loj′ľ-k l] pertaining to or emanating from serology.

    • s. test one involving examination of blood serum usually for antibody.
  • serologist [sēr-ol′ -jist] a specialist in serology. An old term for immunologist.
  • serology [sēr-ol′ -je] the detection of antigen–antibody reactions in vitro.
  • serolysin a lysin of the blood serum.
  • seroma [sēr-o′m ] a collection of serum in the body, producing a tumor-like mass.
  • seromembranous [sēr″o-mem′br -n s] pertaining to or composed of serous membrane.
  • seromucoid glands [sēr″o-mu′koid] glands that secrete mucus and serous fluid; these glands occur in the skin of the muzzle and lip of ruminants and the skin of the snout and lip, and the caudomedial aspects of the carpus, of the pig.
  • seromucous [sēr″o-mu′k s] both serous and mucous.
  • seromuscular [sēr″o-mus′ku-l r] pertaining to the serous and muscular coats of the intestine.

    • s. suture a suture placed across the serosa and muscular layers, but not the mucosa, of the bowel. Used in the closure of enterotomy incisions.
  • seronegative [sēr″o-neg′ -tiv] showing a negative serum reaction; i.e., an animal with no detectable serum antibodies to a specified antigen.
  • seropositive [sēr″o-poz′ľ-tiv] showing positive results on serological examination, i.e., an animal with detectable serum antibodies to a particular antigen.
  • seroprognosis [sēr″o-prog-no′sis] prognosis of disease based on results of immunologic testing of serum.
  • seroprophylaxis [sēr″o-pro″f -lak′sis] the injection of immune serum for protective purposes.
  • seropurulent [sēr″o-pu′roo-l nt] both serous and purulent.
  • seropus [sēr′o-pus″] serum mingled with pus.
  • seroreaction [sēr″o-re-ak′sh n] any reaction taking place in serum, or as a result of the action of a serum.
  • seroresistant [sēr″o-re-zis′t nt] showing a seropositive reaction to a pathogen after treatment.
  • serosa [sēr-o′s , sēr-o′z] any serous membrane.
  • serosanguineous [sēr″o-sang-gwin′e- s] composed of serum and blood.
  • seroserous [sēr″o-sēr′ s] pertaining to two serous surfaces.
  • serositis [sēr″o-si′tis] inflammation of a serous membrane.

    • s.–arthritis of sheep and goats see caprine arthritis–encephalitis.
    • transmissible s. see sporadic bovine encephalomyelitis.
  • serosity [sēr-os′ľ-te] the quality of serous fluids.
  • serosurvey [sēr″o-sur′va] a screening test of the serum of animals at risk to provide data about specific diseases.
  • serosynovitis [sēr″o-sin″o-vi′tis] synovitis with effusion of serum.
  • serotherapy [sēr″o-ther′ -pe] the treatment of infectious disease by the injection of serum from immune animals.
  • serotonergic [ser″o-tōn-ur′jik] serotoninergic.
  • serotonin [ser″o-to′nin] a hormone and neurotransmitter, 5-hydroxytryptamine (5-HT), found in many tissues, including blood platelets, intestinal mucosa, pineal body, and central nervous system; it has many physiological properties, including inhibition of gastric secretion, stimulation of smooth muscles, and production of vasoconstriction.

    • selective s. reuptake inhibitors (SSRIs) a group of compounds inhibiting serotonin reuptake in presynaptic neurons of the central nervous system; used in the treatment of mental disorders.
    • s. syndrome an excess of serotonin, brought about by treatment with drugs or combination of drugs that increase serotonin and serotonin activity, including monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, opioids, tricyclic antidepressants, and some herbs; a serotonin toxicty.
  • serotoninergic [ser″o-to″nin-ur′jik] pertaining to neurons that release serotonin as a neurotransmitter, as those of the raphe nuclei of the brainstem, or that secrete serotonin as a hormone.
  • serotype [sēr′o-tīp″] the type of a microorganism determined by its constituent antigens based on one of several different antibody–antigen reactions, or a taxonomic subdivision based thereon.
  • serous [sēr′ s] 1. pertaining to serum; thin and watery, like serum. 2. producing or containing serum.

    • s. atrophy see serous atrophy.
    • s. cells one of the two kinds of cells in the acinar portions of salivary glands. Contain secretory granules the precursors of salivary amylase. Their secretion is serous and of low specific gravity.
    • s. membrane see serous membrane.
    • s. membrane inflammation see serositis.
    • s. ovarian inclusion cysts may be mistaken for cystic follicles but play no part in ovarian activity.
  • serovaccination [sēr″o-vak″sľ-na′sh n] injection of antiserum combined with the administration of a modified live or killed microorganism to produce passive and active immunity. See serum-virus simultaneous immunization.
  • serow (Capricornis spp.), medium-sized, goat-antelopes in the subfamily Caprinae, native to central or eastern Asia.
  • serpiginous [s r-pij′ľ-n s] creeping from part to part; having a wavy border like a snake.
  • Serpulina previously a genus of bacteria in the order Spirochaetaceae. Several species were previously in the genus Treponema. Now called Brachyspira.
  • serrated [ser′āt-ed] having a sawlike edge or border.
  • Serratia [s -ra′she-] gram-negative, flagellated rods, members of the family Enterobacteriaceae, found commonly in water, soil, and food and only occasionally in pathological specimens. S. marcescens and S. liquefaciens are rare causes of bovine mastitis. S. marcescens can cause significant disease in insects.

    • S. rubidaea a nonpathogen sometimes used as a marker because of the red colonies it produces.
  • serration [s -ra′sh n] 1. the state of being serrated. 2. a serrated structure or formation.
  • Serratospiculum a genus of spirurid nematode of the family Diplotriaenidae infecting the air sacs of raptorial birds.
  • Sertoli cell [ser-to′le] any of the elongated cells in the tubules of the testes to which the spermatids become attached; they provide support, protection and, apparently, nutrition until the spermatids are transformed into mature spermatozoa.

    • ovarian S. c. tumor Sertoli–Leydig tumor of an atopic ovary in a bitch, commonly associated with cystic endometrial hyperplasia.
    • testicular S. c. tumor occurs most commonly in dogs, particularly in retained testicles. Production of estrogen may cause feminization in which the dog is attractive to other males with reduced libido, feminine distribution of body fat, symmetrical alopecia, atrophy of the penis, increased size of the mammary glands and prepuce, and prostatic enlargement. Rarely there is depression of bone marrow activity with anemia, thrombocytopenia, and granulocytopenia.
  • serum [sēr′ m] pl. sera, serums [L.] the clear portion of any animal or plant fluid that remains after the solid elements have been separated out. The term usually refers to blood serum, the clear, straw-colored, liquid portion of the plasma that does not contain fibrinogen or blood cells, and remains fluid after clotting of blood. Blood serum from animals whose bodies have built up antibodies is called antiserum or immune serum. Inoculation with such an antiserum may provide temporary, or passive, immunity against the disease.

    • s. albumin mastitis test a high concentration of serum albumin in milk indicates the presence of mastitis in the quarter.
    • antilymphocyte s. see antilymphocyte serum.
    • s. breaks in classical swine fever (hog cholera) vaccination when a serum-simultaneous vaccination program is not effective, and it is assumed that the hyperimmune serum was ineffective. An outdated method of immunization.
    • s. clot time see prothrombin consumption test.
    • s. enzymes enzymes of individual tissues are released into the blood when the tissue is damaged or when there is much activity in it. The concentrations are used as a measure of activity or injury.
    • s.-fast bacteria that are resistant to the effects of serum.
    • s. glutamic–oxaloacetic transaminase (SGOT) see aspartate aminotransferase.
    • s. glutamic–pyruvic transaminase (SGPT) see alanine aminotransferase.
    • immune s. serum from an immunized animal, containing specific antibody or antibodies.
    • s. osmolality a measure of the number of dissolved particles per unit of water in serum. See also serum osmolality.
    • pooled s. the mixed serum from a number of animals.
    • s. protein see serum protein.
    • s. sickness a group of antibody-mediated hypersensitivity reactions (also referred to as type III hypersensitivities) that includes Arthus reaction, serum sickness, and immune complex diseases. The pathogenesis involves formation of antibody–antigen complexes in the walls of small blood vessels; the complexes fix complement and cause necrosis and thrombus formation. There is infiltration of polymorphonuclear cells from which lysosomal enzymes are released.
    • s. thymic factor a nonapeptide produced by the thymic epithelium that is involved in development of T-cell differentiating. Also known as thymulin.
    • s.-virus simultaneous immunization an outdated method of vaccination, most popular at one time in the vaccination of pigs against classical swine fever (hog cholera). Live virus and antiserum to the virus were injected into the patient simultaneously; breakdowns in the system were frequent, leading to severe outbreaks of the target disease.
  • serumal [sēr-oo′m l] pertaining to or formed from serum.
  • service mating; the physical act of natural mating.

    • s. boots padded boots worn by mares during mating to prevent them injuring the stallion by kicking.
    • s. collar a broad leather pad worn over the withers by mares during mating to prevent the stallion injuring them by biting.
    • hold to s. an animal that has successfully conceived following natural mating or artificial insemination and does not return to heat.
    • s. hobbles worn by mares during mating to prevent them kicking the stallion.
    • s. period in a controlled mating program the period during which the males are left in with the breeding females, or during which inseminations are carried out.
  • service animals defined by the Americans with Disabilities Act (ADA) as animals, usually dogs, that are individually trained to do work or perform tasks for people with disabilities. Examples are guiding people who are blind, alerting people who are deaf, pulling a wheelchair, retrieving dropped items, barking to alert while protecting a person who is having a seizure, reminding a person to take prescribed medications. Federal laws allow service dogs to accompany a disabled handler into stores, restaurants, schools, motels, trains, buses, and on airline flights. Service dogs also qualify for condominiums, apartments, and rental homes where pets aren’t allowed. Dogs whose sole function is to provide comfort or emotional support do not qualify as service animals under the ADA. Most countries have equivalent laws. See also assistance dogs, emotional support animals, guide dog.
  • services per conception a measure of the fertility of a herd; the number of services required to effect a pregnancy.
  • serving see mating.
  • serving capacity test supplementary to a physical examination of a male’s genitalia and of semen, the testing of a male’s capacity to mate with several females during a set test period.
  • sesamoid [ses′ -moid] 1. denoting a small nodular bone embedded in a tendon or joint capsule. 2. a sesamoid bone. See Table 9.

    • carpal s. bone a small sesamoid in the tendon of the abductor pollicis longus muscle of the dog.
    • ectopic s. bone an anatomically inexact, and no longer used, name for ununited anconeal process.
    • metacarpal s. proximal sesamoid bone. See Table 9.
  • sesamoiditis [ses″ -moi-di′tis] excessive strain on the suspensory apparatus, including the proximal sesamoid bones, leading to bone resorption. Characterized by lameness, pain on deep pressure, heat, and pain of the suspensory ligament.
  • Sesbania plant genus in the legume family Fabaceae. Annual herbaceous plants with a confused terminology but similar in their toxicity. Contain galactomannan, a toxic gum that causes diarrhea. Called also Glottidium spp., Daubentonia spp., rattlepod, bagpod, coffee bean, rattlebox, rattlebrush, poison bean, riverhemp, and many others.
  • sesqui- word element. [L.] one and one-half.
  • sesquiterpene common group of plant poisons, e.g., ipomeanols, ngaiones, sporidesmin, furanoid sesquiterpenes, sesquiterpene lactones.

    • s. lactones plant poisons found in Geigeria, Hymenoxys, Helenium spp., Iphenia aucheri, Parthenium hysterophorus.
  • Sessea brasiliensis South American plant in the family Solanaceae; causes serious losses in livestock. Poisoning characterized by hypothermia, bradycardia, incoordination, convulsions, and severe liver injury. The toxic agent is thought to be a polypeptide.
  • sessile [ses′il] not pedunculated; attached by a broad base.

    • s. wart without pedicle.
  • set-fast the area of superficial skin gangrene that develops on an acute saddle pressure sore on a horse’s back.
  • seta [se′t ] a bristle. Called also chaeta.
  • setaceous [se-ta′sh s] bristle-like.
  • Setaria¹ [se-tar′e- ] a genus of filarioid worms in the family Onchocercidae found usually in the peritoneal cavity of ungulates. They cause no apparent clinical illness unless they invade abnormal tissues such as the central nervous system.

    • S. altaica found in the deer Cervus canadensis asiaticus.
    • S. cervi found in deer and possibly buffalo. Possibly also in the spinal cord of deer causing spinal nematodiasis.
    • S. congolensis found in pigs.

      S-45.

      

      Caudal view of fetlock demonstrating enlargement of the medial sesamoid secondary to severe sesamoiditis.

      S-46.

      

      Setaria spp., the abdominal worm of cattle.

    • S. cornuta found in antelope.
    • S. digitata found in cattle, buffalo. May also occur in the urinary bladder in these species and in the central nervous system of sheep, goats, and horses. Causes cerebrospinal nematodiasis.
    • S. equina found in horses and in the eyes, scrotum, pleural cavity, and lungs as well as the peritoneal cavity. Found also in the eyes of cattle.
    • S. labiato-papillosa found in cattle, deer, giraffe, antelope.
    • S. marshalli found in sheep.
    • S. tundrae found in reindeer.
    • S. yehi found in deer, moose, caribou, bison.
  • Setaria² genus in the grass family Poaceae. Economically and ecologically, the genus is quite important. Several cultivars are used commercially as pasture grasses. In general, palatable and nutritious. Some species are noxious weeds in crops and lawns. Two species are associated with toxicological problems including S. glauca (S. lutescens) and S. italica.

    • S. glauca (yellow foxtail, bristly foxtail, yellow bristlegrass, pigeongrass) a grass with bristly seedheads and causes a traumatic stomatitis in cattle and horses. The barbed bristles can penetrate the muscous membranes and skin and migrate through tissues.
    • S. italica (foxtail millet) can cause sudden onset of myoarthropathy with signs of lameness, painful joints, and sweating; but disease is rare
  • seton [se′ton] 1. a thin woven fabric wick, 6 in. × 0.25 in., used as a primitive vaccination technique by dipping the seton in a bowl of ‘vaccine’, e.g., pleural exudate from a case of contagious bovine pneumonia. 2. a thread of gauze or other suture material threaded through tissue and used to keep a wound open.
  • Setosphaeria rostrata the teleomorph of the fungus Exserohilum rostratum.
  • setter a type of gundog characterized by hunting behavior in which it pursues game by scent then freezes (‘sets’) to indicate it has found the quarry rather than chasing or flushing it out. Includes English setter, Gordon setter, Irish setter, Irish red and white setter.
  • setterwort Helleborusfoetidus.
  • setting 1. said of meat while it is cooling after slaughter and the processes of rigor mortis are precipitating the protein in the muscle fibers. 2. a clutch of eggs to set under a broody hen—usually 13 eggs.
  • setting sun sign ventrolateral strabismus associated with hydrocephalus and lesions of the midbrain.
  • settled lay term for an animal that has become pregnant. Generally applied to agricultural animals.
  • Seutin shears heavy duty shears for cutting plaster cast. Blades are angled to one side so that bottom, bulb-pointed blade can be inserted under plaster without the handles getting in the way.
  • severe a clinical qualifier that describes a disease that is so severe that it dominates all other activities.

    • s. combined immune deficiency disease (SCID) (syndrome) see combined immune deficiency syndrome (disease).
  • severe acute respiratory syndrome (SARS) an often fatal flu-like respiratory disease of humans caused by the SARS coronavirus in which symptoms invariably include fever above 38°C and may include myalgia, lethargy, gastrointestinal symptoms, cough, sore throat, and other nonspecific symptoms. The virus originates in bats, notably wild Chinese horseshoe bats (Rhinolophus sinicus), and is amplified through intermediate hosts such as caged palm civets in live animal markets in Southern China prior to infection of humans and perhaps other animals.
  • severity-of-disease scoring system a modification of the APACHE system, for use in dogs.
  • sevoflurane [se″vo-floo′rān] a halogenated ether inhalant anesthetic with rapid induction and short recovery periods.
  • sewage [soo′ j] human sewage is utilized for animal husbandry purposes as a fertilizer for pastures in some countries. It may be in the form of crude sewage or as the sediment in settling tanks. It may cause cadmium or lead poisoning, or spread infectious disease, e.g., salmonellosis, and is the major risk factor for beef measles, see Cysticercus bovis.

    • crude s. has caused goiter in the calves of cows grazing the pasture and is a risk for a number of diseases such as salmonellosis, cysticercosis.
    • s. sludge the sediment of sewage collected in settling tanks.
  • sex [seks] 1. the fundamental distinction, found in most species of animals and plants, based on the type of gametes produced by the individual or the category to which the individual fits on the basis of that criterion. Ova, or macrogametes, are produced by the female, and spermatozoa, or microgametes, are produced by the male. The union of these distinctive germ cells results in the production of a new individual in sexual reproduction. 2. to determine the sex of an animal.

    • s. cell see germ cell, gamete.
    • s. chromatin the persistent mass of chromatin situated at the periphery of the nucleus in cells of normal females; it is the material of the inactivated sex chromosome. Called also Barr body.
    • chromosomal s. sex as determined by the presence of the XX (female) or the XY (male) genotype in somatic cells, without regard to phenotypic manifestations. Called also genetic sex.
    • s. cycle 1. the physiological changes recurring regularly in the reproductive organs of female mammals when pregnancy does not supervene. 2. the period of sexual reproduction in an organism that also reproduces asexually.
    • s. chromosomes see sex chromosomes.
    • s. determination 1. the change in the fetus to a male or female configuration; the process by which the sex of an organism is fixed, associated, in animals, with the presence or absence of the Y chromosome. 2. diagnosis of the sex of the fetus before birth performed by examination of fetal fluids obtained by amniocentesis; see also sexing.
    • s. determining region of Y a single gene responsible for determining the sex of an animal.
    • s. drive see libido.
    • endocrinological s. the phenotypic manifestations of sex determined by endocrine influences, such as mammary development, etc.
    • genetic s. chromosomal sex.
    • s. glands in the male includes the prostate, vesicular glands (seminal vesicles), ampullae, and bulbourethral glands.
    • gonadal s. the sex as determined on the basis of the gonadal tissue present (ovarian or testicular).
    • s. hormones glandular secretions involved in the regulation of sexual functions. The principal sex hormone in the male is testosterone, produced by the testes. In the female the principal sex hormones are the estrogens and progesterone, produced by the ovaries. These hormones influence the secondary sex characters, such as the shape and contour of the body and head, mammary development, and the pitch of the voice. The male hormones stimulate production of spermatozoa, and the female hormones control ovulation, pregnancy, and the estral cycle.
    • sex-linkage includes X-linked (much the most common) and Y-linked loci.
    • sex-linked inheritance see sex-linkage (above).
    • morphological s. sex determined on the basis of the morphology of the external genitals. Also called phenotypic sex.
    • neutrophil s. lobe see drumstick lobe.
    • nuclear s. the sex as determined on the basis of the presence or absence of sex chromatin in somatic cells, its presence normally indicating the XX (female) genotype, and its absence the XY (male) genotype.
    • s. parity see sex ratio (below).
    • s. pheromone see pheromone.
    • s. ratio proportion of female to male births.
    • s. reversal the sexual condition of animals in which gonadal sex and chromosomal sex are dissimilar.
    • s. steroids steroidal compounds acting as hormones in reproductive processes; the principal ones are estrogen, progesterone, testosterone.
  • sex-associated said of diseases that are predisposed to or affected in their severity by the sex of the animal.
  • sex-conditioned sex-influenced.
  • sex-cord stromal tumor ovarian tumors of granulosa and thecal cells and their luteinized forms.
  • sex-influenced [seks-in′floo- nst] denoting an autosomal trait that is expressed differently, either in frequency or degree, in males and females.
  • sex-limited [seks-lim′it- d] affecting individuals of one sex only.

    • s-l. genes genes present in both sexes of a species, but expressed in only one sex and not expressed in the other; e.g., the two sexes show different phenotypes despite having the same genotype. For example, milk production is a sex-limited trait expressed only in females; males have, but do not express, the genes for milk production. Sex-limited genes are only those on autosomes, e.g., they are not sex-linked traits
  • sex-linked [seks′linkt] determined by a gene located on a sex chromosome. Although a trait may be X-linked or Y-linked, virtually all clinically significant sex-linked traits are transmitted by genes located on the X chromosome; therefore, the terms sex-linked and X-linked are often used synonymously. See also sex-linked gene.
  • sex reversal condition in which chromosomal and gonadal sex differ in an individual.
  • sexing determination of the sex; usually referable to immature animals. ‘Sex identification’ is alternate preferred term. Usually carried out on day-old chickens by examining inside the vent for small eminences. Up to 1000 chickens can be sexed per hour with 98% accuracy.

    • automatic s. may be possible when identification or separation of the sexes occurs automatically, e.g., by the occurrence of breeds of fowl that indicate their sex by the color pattern of their feathers, or by a genetically engineered lethal gene in a sex chromosome. Called also autosexing. See also Z-linked sexing.
    • embryo s. technology used to determine the gender of an embryo in the laboratory before its transfer; based on the presence or absence of the Y chromosome in a sample of cells.
    • fetal s. determination of sex of fetus, often by ultrasonography.
    • probe s. use of a blunt ended probe, usually metal, inserted into the cloaca of snakes or lizards, and directed toward the tail. The distance entered is greater in males, as it enters the inverted hemipenal pockets, compared to the shorter pocket present in females.
    • semen s. process of separation of X-bearing and Y-bearing spermatozoa in the ejaculate in order to produce inseminates that are directed to the production of the desired sex of the offspring; presently available commercially for a variety of production animals (swine and cattle).
  • sextan recurring on the sixth day (every 5 days).
  • sexual [sek′shoo- l] pertaining to sex.

    • s. behavior includes masturbation, courtship, mating, estral display.
    • s. cycle estral cycle.
    • s. differentiation identification of the sex of a patient is done usually by an examination of external genitalia; preparation and examination of a karyotype is the preferred laboratory method.
    • s. dimorphism differences in structure or physical characteristics between males and females of the same species, e.g., horns in some breeds of sheep, feather coat color in many species of birds.
    • s. intercourse see mating.
    • s. maturity the age at which an animal reaches the peak reproductive performance; in the male is maximum sperm production, in the female is the ability to get pregnant and carry to term. Occurs at different ages in different species and in different breeds.
    • s. receptivity behavioral changes in female animals at the time of estrus; involves acceptance of male efforts at copulation and, in some species, actively seeking the male.
    • s. rest circumstances in which no sexual intercourse takes place.
  • Seymour Jones disinfection method a method used in the disinfection of hides. Consists of immersion in a solution of 1:5000 solution of bichloride of mercury plus 1% formic acid for 24 hours.
  • Sézary syndrome a rare epitheliotropic T cell lymphoma characterized by erythroderma, pruritus, generalized peripheral lymphadenopathy, and the presence of ‘Sezary cells’ in the cutaneous infiltrate and in the peripheral blood. Skin biopsy specimens are indistinguishable from mycosis fungoides. The Sézary cell is a characteristic cerebriform lymphocyte that occurs in the dermis and blood of patients with Sézary syndrome. It has a distinctive markedly convoluted nuclear membrane.
  • SG specific gravity.
  • Sg chemical symbol, seborgium.
  • SGOT serum glutamic–oxaloacetic transaminase; see aspartate aminotransferase.
  • SGPT serum glutamic–pyruvic transaminase; see alanine aminotransferase.
  • SGPV sheep and goat pox virus.
  • SH sulfhydryl.
  • shackle a bar 2.5-ft long with an iron loop at either end, used in restraint of large pigs. A chain is threaded through the loops and around the lower hindlimbs of the pig. When the chain is pulled the pig is stretched and is cast with the limbs held wide apart. A similar device is used in the abattoir to lift the live pig before it is slaughtered and scalded.
  • shackling see shackle.
  • shadow a dark area.

    • acoustic s. an ultrasound artifact seen as a dark area on the image deep to a strong absorber or a strong reflector. Can be classified as a clean or dirty shadow
    • clean s. an ultrasound artifact due to the absorption of sound by a structure, leading to a clear, dark shadow distal (deep) to the structure. Commonly seen arising from cystic calculi and gastrointestinal foreign bodies.
    • dirty s. an ultrasound artifact due multiple reflections of sound from materials such as gas. Commonly seen arising from gas within the small intestine. See reverberation.
  • shadow-casting [shad″o-kast′ing] application of a coating of gold, chromium, or other metal for the purpose of increasing contrast and thereby the visibility of ultramicroscopic specimens under the electron microscope. The heavy metal is evaporated under vacuum and deposited on the surface of the specimen.
  • shadow cell [shad′o] one that appears in a section only as an outline. Called also ghost cell.
  • shadow roll [shad′o] a thick roll of material, usually sheepskin, worn on the nose band of a bridle while racing to avoid having the horse shy at a shadow on the ground.
  • shadow test [shad′o] see retinoscopy.
  • shadowgram the shades of gray at the edge of an image on a radiograph. They are the features that the expert can interpret; they define the silhouette of the object being imaged.
  • shaft [shaft] a long slender part, such as the portion of a long bone (the diaphysis) between the wider ends or extremities, the shaft of a hair and the central shaft (or rachis) of a feather.
  • shafty said of wool in which the staples are long, wide, and thick.
  • shaggy heart [shag′e] see cor villosum.
  • shaker calf syndrome inherited degenerative disease of spinal cord in Hereford and Holstein–Friesian cattle characterized by neonatal tremor, paresis, spastic gait, aphonia, terminal spastic paraplegia.
  • shaker dog disease a syndrome of generalized muscle tremors, hypermetria, and occasionally seizures, aggravated by excitement or handling, seen most often in young, mature dogs of the West Highland White and Maltese breeds, but sporadically in many small breeds. The cause is unknown but an acquired immune-mediated condition is suspected based on the condition’s response to immunosuppressive doses of corticosteroids. Called also corticosteroid responsive tremor syndrome, idiopathic cerebellitis, little white dog shaker disease.
  • shaker foals toxicoinfectious form of botulism, a disease of young foals characterized by progressive muscular weakness, inability to stand, and gross muscle tremor when standing. Associated with presence of Clostridium botulinum type B.
  • shaker lambs see border disease.
  • shaker pigs see congenital tremor syndrome.
  • Shaker pup colloquial term used to refer to puppies with congenital disorders of myelin formation, caused by mutations in the FNIP2 gene. In Springer spaniels the condition X-linked, progressive, and usually fatal, while in Weimaraners, the condition is recessive and clinical signs improve with age.
  • sham drinking [sham] the phenomenon of an animal constantly playing with its drinking water but drinking little. A common sign in a horse with colic.
  • sham feeding [sham] intake of food by an animal with a surgically created esophageal fistula that prevents the ingested food from reaching the stomach. Used in studies of physiological and psychological mechanisms of hunger and feeding behavior.
  • sham urination [sham] most apparent in horses that stretch out to urinate, males relax the penis but urine is not passed; common sign in subacute colic. There is no grunting or straining to pass urine as there is in urethral obstruction.
  • shampoo a cleaning agent, usually liquid, for hair; usually consists of a detergent and perfume. Some, usually referred to as medicated shampoos, contain therapeutic substances such as parasiticides, antimicrobials, ketatolytic agents, and antiseborrheic compounds such as selenium sulfide.
  • shank [shangk] 1. the tibia or shin; a leg-like part. In the dog fancy, shank refers to the hindlimb between the hip and stifle. 2. the lead part of a halter.
  • shankings wool, usually containing hair fibers, from below the knees and hocks.
  • shaping [shāp′ing] a learning technique using gradual approximations to the desired response with reward at each step.
  • share-farm a common form of farm lease arrangement; the land-owner leases the grazing and cropping rights to his land, natural resources and usually facilities including house, hay shed, milking parlor, in return for a share in the income of the enterprise.
  • sharemilking the unit is contracted to a person or firm to milk and manage the herd and farm for a share of the milk income.
  • Sharlea a type of sheep, called after a locality in Australia where they were developed by the Sharlea Sheep Society. The sheep are superfine Merinos with an average fiber diameter of less than 17 microns. The sheep are kept indoors at all times and are usually clad in nylon coats to minimize contamination of the wool that is used in the manufacture of superior garment fabrics.
  • Shar-Pei a medium-sized, compact dog with distinctive, loose skin that forms many deep wrinkles over the entire body, particularly on the large head, which has been compared to the look of a hippopotamus. The triangular ears are small and folded close to the head; the small eyes are almost hidden in the skin folds. The oral mucosa is colored lavender to dark bluish-black. There are two types of coat; one is very short and extremely harsh (‘horse coat’), the other is slightly longer and brushy (‘brush coat’). A third type of coat (‘bear coat’) is longer (more than 1 in.), softer and sometimes wavy; considered a breed fault. The breed is predisposed to a variety of skin disorders and entropion, all associated with the skin folds, and a familial renal amyloidosis. In the US, called Chinese Shar pei.
  • sharp freezers freezing chambers for meat preservation that operate at lower temperatures than the average freezer, i.e., at 0°F (−18°C).
  • Sharpey’s fibers [shahr′pe] see fiber¹.
  • sharps 1. needles, scalpel blades, broken ampoules; anything in a hospital or clinic that can cause injury to those involved in their disposal. 2. see calkins.

    • s. container (1) container where sharps can be placed for safe disposal; required by law in most jurisdictions.
  • Shasta River crud see equine neorickettsiosis.
  • Shattenfroh method a method for disinfecting hides; the hides are soaked in a solution of 2% hydrochloric acid and 10% sodium chloride for 48 hours.
  • shaver [sha′v r] an instrument used in arthroscopic surgery for the rapid debridement of tissues such as diseased articular cartilage and proliferative synovial lining.
  • shavings curly wafers of wood produced when trimming wood with a plane; used as bedding for livestock. See also sawdust.
  • SHBG sex hormone-binding globulin.
  • shear [shēr] 1. to remove the fleece of a sheep. 2. pressure on a mass in such a way that planes within it are pressured to move in a direction parallel to the pressure. Any movement is proportional to the distance from the plane at which movement occurs.

    • s. injury injury to tissues caused by shear pressure. See shearing injuries (2).
    • s. stress the stress to which a tissue is subjected by a shear force without injury actually occurring.
  • shearer person whose occupation is shearing sheep.
  • shearing mechanical removal of the sheep’s fleece. A traumatic event in the sheep’s annual calendar. A time for the transmission of diseases between sheep, e.g., mycotic dermatitis, caseous lymphadenitis, infection with environmental infections, e.g., gas gangrene, tetanus, and for exposure to inclement weather without the protection of a fleece. Chemical shearing, the shedding of the fleece after administration of a chemical agent, could avoid the use of a mechanical handpiece and improve both the quality of the wool and the welfare of the sheep, but is still, after many years, in the very early stages of exploration. Cyclophosphamide and mimosine have been used experimentally but there is no commercially available system. Bioclip®, a biological defleecing process using epidermal growth factor and developed by CSIRO is available. Automatic shearing done by robots has also been proposed. Breeding of sheep that shed their fleece annually is another possibility. The Wiltshire horned breed and Shetland do this to a varying degree.

    S-47.

    

    Shar pei.

    • s. board open area in a shearing shed on which the sheep are restrained while they are shorn.
    • s. hypothermia see hypothermia.
    • s. injuries 1. injuries inflicted to a sheep during shearing and by the shearing machine. Lacerations are frequent but cause little damage if they do not become infected. They appear to cause no discomfort and heal very quickly. The serious injuries are the removal of teats in ewes, damage to the prepuce, and removal of the tip of the vulva. The last two lead to deviation of the stream of urine, fouling of the nearby fleece, and increased risk of blowfly strike. 2. injuries in which there is the application of a shearing force tending to cause local deformity or displacement; usually involve the carpus or tarsus in small animals hit by motor vehicles. There is extensive loss of soft tissues and bone, with exposure of the joint.
  • shearmouth abnormally increased occlusal angulation of the cheek teeth; for example >40° for mandibular cheek teeth and >25° for maxillary cheek teeth in equines.
  • shears cutting instruments for the removal of wool—sheep shears, or for trimming the hooves of sheep and goats—hoof shears.

    • hoof s. a rugged pair of shears like secateurs but with sharp-pointed blades. The spring in the handle keeps the blades open and pressing the handles shut operates the shears.
    • plaster s. see plaster shears.
    • sheep s. 1. hand shears are sharp-pointed, with wide blades and have a spring at the handle that opens the blades. They have to be closed to cut the wool. 2. mechanical or power shears are driven by a rotating, flexible shaft converting to a reciprocating movement of a cutter in a comb at right angles to the shearer’s hand; the cutter and comb comprise the handpiece.
  • sheath [shēth] 1. a tubular case or envelope. 2. vernacular for prepuce. 3. a tubular instrument used to protect endoscopic instruments when placed through the body wall or joint. Sheaths also provide access for the passage of instruments, and the ingress and egress of fluids or gases as required for an endoscopic procedure.

    • arachnoid s. the delicate membrane between the pial sheath and the dural sheath of the optic nerve.
    • carotid s. a portion of the cervical fascia enclosing the carotid artery, internal jugular vein, and vagus or vagosympathetic nerve.
    • carpal tendon s’s sheaths to the tendons of the muscles that course over the carpus.
    • crural s. femoral sheath.
    • dural s. the external investment of the optic nerve.
    • external r. sheath epithelial layer acting as a sheath to the root a hair; continuous with the germinal matrix at the base of the developing follicle.
    • femoral s. the fascial sheath of the femoral vessels.
    • Henle’s s. the endoneurium, especially the delicate continuation around the terminal branches of nerve fibers.
    • lamellar s. the perineurium.
    • medullary s., myelin s. the sheath surrounding the axon of myelinated nerve cells, consisting of concentric layers of myelin formed in the peripheral nervous system by the plasma membrane of Schwann cells, and in the central nervous system by the plasma membrane of oligodendrocytes. It is interrupted at intervals along the length of the axon by gaps known as nodes of Ranvier. Myelin is an electrical insulator that serves to speed the conduction of nerve impulses.
    • pial s. the innermost of the three sheaths of the optic nerve.
    • root s. the epidermal layer of a hair follicle.
    • s. of Schwann neurilemma.
    • synovial s. a synovial membrane sleeve through which a tendon moves; found commonly where a tendon passes over a joint.
  • sheath rot see enzootic balanoposthitis.
  • Sheather’s flotation method a method for examining feces for the presence of worm eggs or larvae by mixing with a saturated solution of sodium chloride or sugar and collecting a sample from the top of a column for microscopic examination.
  • shechita, shehita the Jewish method of ritual slaughter in which the animal is killed by one stroke of a very sharp knife across the throat, completely severing the trachea, carotid arteries, and jugular veins. Called also schechita.
  • shed rural building used for agricultural pursuits.

    • s. hands miscellaneous workers in a shearing shed at shearing time, i.e., persons other than the shearers, wool classers.
    • commodity s. a three-sided, roofed building that allows easy front loader access, where commodities are individually stored on a farm.
    • s. lambing a system of indoor lambing for ewes that normally run at pasture so that the lambs have protection against the inclemency of the weather, and where close observation can be maintained over every ewe. The ewes are brought in when they are individually on the point of lambing and moved out as soon as the ewe–lamb bond is established and the lamb is vigorous, usually 24 hours.
    • shearing s. contains a shearing ‘board’ supplied with a number of ‘stands’ that are locations for shearing machines. The sheep are shorn on the ‘board’ and are pushed out through small doors down chutes into counting pens where they are held until a sufficient group is accumulated. In the shed, the sheep to be shorn are held in catching pens. The shed is usually large enough to hold several hundred sheep overnight so that there will be some dry sheep for the morning. The shorn wool is classed and packed into bales in the shed that is usually high off the ground; the droppings fall through the slatted floor.
    • s. sheet standard recording medium for dairy cow reproductive data—a structured cardboard poster pinned on the wall of the milking shed. Replaced in some sheds by a computer terminal.
  • shedding 1. exfoliation of entire skin, called also ecdysis, exuviate. 2. falling out of haircoat. 3. putting animals into a shed. 4. excretion of an infectious agent from the body of an infected host.

    • s. agent an agent, e.g., a wild animal, shedding an infectious agent.
  • Sheena’s goldDuranta erecta
  • sheep member of the species Ovis aries. They are classified into several types including Merino, shortwool meat breeds, longwool, carpetwool, fat-tail, wool-shedding, Karakul. All domesticated types are characterized by a wool fleece.

    • Bighorn s. see Bighorn sheep.
    • carpetwool s. includes Blackfaced mountain, Carpetmaster, Drysdale, Elliottdale and Tukidale.
    • Dall s. see Dall sheep.
    • s. dip see dip.
    • dual-purpose s. breeds generated to provide meat and wool. Include Charollaise, Corriedeale, Cormo, Dormer, Gromark, Perendale, Polwarth, Zenith.
    • easy-care s. see easy-care sheep.
    • fat-tailed s. see fat-tailed sheep.
    • s.–goat hybrid mating and fertilization can be achieved but the fetus dies early or is aborted.
    • heafed s. sheep such as Herdwicks and Swaledales in the UK that graze the same area of unfenced hill area without shepherding, year after year, and teach this behavior to their lambs. Also called hefted sheep.
    • light s. sheep light in condition off subsistence range and destined to go to irrigated pasture or into a feedlot for fattening.
    • meat s. includes English Longwool breeds (see under wool sheep below) and shortwool or Downs sheep, e.g., Southdown, Suffolk, Hampshire, Oxford down, Dorset horn, Poll Dorset, Ryeland, Shropshire and Charollaise, Cheviot, Clun Forest, Colbred, Columbia, Coopworth, Dormer, Dorper, many indigenous fat-tailed and fat-rumped breeds, Finnish-Landrace, North Ronaldsay, Wensleydale.
    • s. pox see sheeppox.
    • s.-scab see psoroptic mange.
    • wool s. includes Australian Merino (including a wide range of strains and types especially booroola and Comeback), Cormo, Corriedale, Polwarth, Sharlea, American Rambouillet and English Longwools such as Lincoln, Leicester, Border Leicester, Cheviot, Coopworth, Romney Marsh.
  • sheep-associated bovine malignant catarrah virus see malignant catarrhal fever.
  • sheepdog any of various breeds of dogs produced to help manage sheep flocks. Three general types, the herding breeds that bring sheep to the operator, e.g., Border collie, the huntaway breeds that move sheep ahead, e.g., kelpie, and the guarding types that protect the flock from predators, e.g., Komondor. See also shepherd dogs.
  • sheepkill Kalmiaangustifolia.
  • sheeppox a highly contagious, generalized disease of sheep caused by a poxvirus in the genus Capripoxvirus and characterized by the presence of typical pox lesions on the unwoolled skin, especially under the tail. Most adults recover. A much more lethal, generalized disease that resembles smallpox in its pathogenicity occurs in lambs with many dying and showing lesions in the bowel and respiratory system. Endemic and major impacts on small ruminant production in Africa (north of the equator), the Middle East, Turkey and Greece, Central Asia, and the Indian subcontinent. A disease notifiable to the OIE (see Table 21).
  • sheepshead see probatocephaly.
  • sheep’s sorrel Rumexacetosella.
  • shell disease term used to describe pitting of the shell of crustaceans. May have multiple etiologies such as chitinoclastic Vibrio spp. and the fungus Ostracoblabe implexa. The latter has been associated with black malformations on the inside of shell.
  • shell gland the secretory portion of the avian oviduct where the calcareous shell of the egg is deposited; also called the (avian) uterus. Also a glandular organ of some invertebrates that secretes components to form an egg shell.
  • shell rot softening and ulceration of the carapace and plastron of softshell turtles caused by the bacteria Beneckea chitinovora. Called also rust, ulcerative shell disease.
  • shellfish an aquatic animal having a shell; includes molluscs, e.g., oyster, and crustaceans, e.g., shrimp, lobster.

    • paralytic s. poisoning syndrome of flaccid paralysis after ingestion of bivalve molluscs whose tissues have accumulated tetrahydroxypurine toxins from some marine dinoflagellates; syndrome identical with tetrodotoxin poisoning. See also saxitoxin. Called also PSP.
  • shellgrit crushed shells of marine crustaceans; mined on ocean beaches where the animals are prolific. Used in rations for some birds to aid digestion.
  • shelly covered in shells; pertaining to or resembling shells.
  • shelter medicine a specialty in veterinary medicine dealing with the requirements of veterinary services in animal shelters, including study and research on the welfare and quality of life of animals in shelters, sheltering systems, preventive medicine, and the management of health problems that occur in such environments.
  • Sheltie a common name for the Shetland sheepdog.

    • s. eye anomaly (SEA) see Collie eye anomaly.
    • s. syndrome see epidermolysis bullosa.
  • Sheng cycle within the Five Element theory of traditional Chinese medicine, this is the creative, engendering, productive, or generating cycle in which each of the elements creates the element to its right in a clockwise direction. Fire promotes Earth, Earth promotes Metal, Metal promotes Water, Water promotes Wood, and Wood promotes Fire, forming a cycle. See also Ke cycle.
  • shepherd dogs any of several dog breeds used in working sheep (sheepdogs), but most commonly applied to the German shepherd dog. See also sheepdog.
  • shepherd’s hook explorer see explorer.
  • Sherman bone plate [shur′m n] the plate is narrowed in the spaces between the screw holes so that it has approximately the same strength at every point.

    S-48.

    

    Shetland pony.

    S-49.

    

    Shetland sheep.

  • Shetland pony miniature or dwarf Scottish pony, most commonly black and dark brown, but can be any color, including broken colors; 9.2–10.2 hands high. Its most common use is as a child’s pony, as depicted in Norman Thelwell’s fabulous cartoons.
  • Shetland sheep ancient breed of small, agile, hardy sheep on the Shetland Islands. There are a wide variety of fleece colors and markings, and the wool is desired by hand-spinners.
  • Shetland sheepdog a small (13–16 in. tall), alert dog with abundant, medium-length haircoat that forms a thick ‘mane’ around the neck. It may be black and white, black and tan, blue merle, sable, or tricolor (black, tan, and white). The head is long, narrow, and flat in profile with small ears that fold over at the tips. The dog looks like a Collie in miniature. The breed is predisposed to collie eye anomaly, retinal atrophy, hemophilia, nasal solar dermatitis, and iris heterochromia. Called also sheltie, sheltie.
  • Shiba inu an ancient breed, it is the smallest (17–23 lb) of the Japanese native dogs, and it was bred as a hunting dog. A medium-sized, muscular dog with a thick coat in red, sesame, or black and tan, all with specified areas of white or cream, mainly on the ventrum. Called also Japanese shiba inu and just Shiba.
  • shift [shift] a change or deviation.

    • antigenic s. see antigenic shift.
    • chloride s. see chloride shift.
    • degenerative left s. an increase in immature neutrophilic granulocytes, in excess of mature cells of the series. A poor prognostic sign, indicating a current inability of the bone marrow to respond adequately to inflammation.
    • frame s. see frame shift mutation.
    • s. to the left an alteration in the distribution of leukocytes in the peripheral blood in which there is an increase in the numbers of immature neutrophils, primarily band forms but metamyelocytes or more immature cells may also be present; usually in response to an infection. See also degenerative left shift (above).
    • s. red cell see macroreticulocyte.
    • s. to the right an alteration in the distribution of leukocytes in the peripheral blood in which there is an increased number of mature neutrophils but no immature cells are present.
  • shiga-like toxins toxins resembling those of Shigella dysenteriae Type 1 produced by Shiga-toxin producing Escherichia coli (STEC), an emerging group of food-borne pathogens originating in ruminants. The principal virulence factors in the pathogenesis of human infections with these organisms, STEC strains elaborate two potent phage-encoded cytotoxins called Shiga toxins (Stx1 and Stx2). They bind to, and damage, endothelial cells in the intestine, kidney, and brain. Lethal to Vero tissue-culture cells and also called verotoxins.

    S-50.

    

    Canine blood smear showing a shift to the left with a segmented neutrophil (left) with toxic vacuolation and a metamyelocyte (right) with two Döhle bodies.

  • Shigella [shľ-gel′ ] a genus of gram-negative rods in the family Enterobacteriaceae. There are four subgroups or species and, although phylogenically not distinct from Escherichia coli, they continue to be treated as separate species because of extensive historical usage. The type species, S. dysenteriae, causes bacillary dysentery in humans and nonhuman primates. Other animals are resistant to infection, but organisms have been isolated from dogs without clinical signs.
  • shigella pl. shigellae. See Escherichia coli Shigella and Shigella.
  • shigellosis [shľ′g l-o′sis] see Actinobacillus equuli septicemia in foals.
  • Shih tzu a small (9–16 lb), lively dog with a very short muzzle, broad, round head, large prominent eyes, and short ears. The luxurious coat is long, straight, and flowing in a variety of colors with a white blaze on the face and a white tip on the tail. Often seen with the hair gathered over the head with a bow or hair adornment, but these are prohibited in the show ring by the Kennel Club UK. Called also Chrysanthemum-faced dog. The breed is predisposed to cleft palate and a familial renal cortical hypoplasia.
  • shin [shin] in horses, the large metacarpal and metatarsal bones, especially the dorsal surface.

    • bucked s’s see sore shins (below).
    • sore s’s periostitis of the shins seen most commonly in 2- and 3-year-old thoroughbreds in hard training, mostly in the forelimbs. The horse is lame and worsens with work. In severe cases an enlargement is visible.
  • Shine–Dalgarno sequence part of the leader sequence preceding the start codon of mRNA that is AGGAGGU or a variant thereof that binds the mRNA to a complementary sequence in the 16S component of rRNA so that translation of the mRNA can proceed.
  • shingle tick Dermacentoralbipictus.
  • shipping 1. movement of any livestock to packing plant or feedlot; usually refers to long distance transport by rail. 2. slang phrase for sale to market or packing plant for immediate slaughter. The choice for the outcome in a damaged animal may be to treat or ship.

    • s. fever see pneumonic pasteurellosis; equine influenza.
  • shippon a stable used for the housing of farm animals.
  • Shire a massive English draft-horse, 17–18 hands high, bay, brown, black, gray, white markings commonly with dark colors; long feather on legs.
  • Shirley drain a vented surgical drainage tube; see drain.
  • Shirodkar technique a surgical procedure for the correction of cervical incompetence in the mare. Uses a strap of fascia lata buried under the mucosa.
  • shiver [shiv′ r] involuntary shaking of the body, as with cold. It is caused by contraction or twitching of the muscles, and is a physiological method of heat production in all animals.
  • shivering [shiv′ r-ing] see shivers, shiver, stringhalt.
  • shivers a rare, progressive neurologic condition particularly of tall horses (> 17 hands) of unknown cause characterized by muscle tremors and hyperflexion of the hind limbs and tail seen when the horse is forced to move backward or to the side, or when the hind foot is lifted. Most common in draft breeds and Warmbloods. There is currently no effective treatment.
  • shochet the operant slaughterer in the Jewish method.
  • shock [shok] a condition of acute peripheral circulatory failure due to derangement of circulatory control or loss of circulating fluid. It is marked by hypotension, coldness of the skin, and tachycardia.

    • allergic s. see anaphylactic shock.
    • s. bodies hyaline globules composed of fibrin degradation products that act as microthrombi and cause hemorrhage and necrosis.

      S-51.

      

      Shire horse.

    • burn s. the loss and redistribution of fluid, electrolytes, and plasma protein, increased blood viscosity, and increased peripheral resistance that follow a severe burn contribute to shock.
    • cardiogenic s. classically associated with acute myocardial infarction in humans; in animals may be caused by intrinsic congestive heart failure, cardiac depression caused by anesthetic overdosage or other drugs with negative inotropism, rarely, thromboembolism.
    • distributive s. see vasogenic shock (below).
    • electric s. see electrical injuries.
    • electroplectic s. electric shock. See also electrical stunner.
    • endotoxic s. caused by endotoxins, especially Escherichia coli. See also toxemic shock.
    • s. gut animals in shock develop changes in the gut including congestion and hemorrhage into the lumen.
    • hypovolemic s. shock due to reduced blood volume as a result of water deprivation, fluid loss due to diarrhea, vomiting, extensive burns, intestinal obstruction, whole blood loss.
    • insulin s. severe hypoglycemia resulting from overdosage with insulin. It is marked by tremor, weakness, convulsions, and collapse, and may lead to multiple organ failure and death.
    • irreversible s. shock that has reached the stage where irreparable damage has been done to tissues, e.g., liver, kidneys and treatment will not salvage the patient although it might prolong life for a long time.
    • s. lung animals in shock due to massive burns, septicemia, disseminated intravascular coagulation (DIC), acute viral or bacterial pneumonias, or trauma develop an acute respiratory distress syndrome. The pulmonary lesion is a nonspecific acute or subacute interstitial pneumonia.
    • nervous s. a temporary cessation of function in nervous tissue caused by an acute insult such as trauma without the part having been directly or detectably damaged. The loss of function is only temporary, usually for a few minutes but it may last for several hours. There may be residual signs due to direct damage when the shock passes. Stunning by a lightning stroke is an example.
    • obstructive s. circulatory failure caused by physical obstruction, e.g., cardiac tamponade or pulmonary embolism.
    • s. organs those organs, specific to each animal species, which respond to allergens circulating in the blood. The main shock organs in cattle and sheep are the lungs, in the horse, cat, and pig the lungs and intestines, and in dogs the liver, specifically the hepatic veins.
    • septic s. see toxemic shock.
    • spinal s. flaccid paralysis up and down the body from the site of a severe spinal cord lesion. Accompanied by a fall in skin temperature, vasodilatation, and sweating. Signs disappear within an hour or two. There may be residual signs due to physical injury to tissue. Species variation exists with spinal shock. In humans, signs may persist for several days, while in smaller vertebrates signs occur for only minutes following the initial injury.
    • toxic s. see toxemic shock.
    • vasogenic s., vasculogenic s. shock exists because of the severe reduction in effective circulating blood volume caused by sequestration of blood and other fluids in the vascular system and their withdrawal from the circulating blood. Is the classical shock of traumatic injury, burns, uterine prolapse, extensive surgery.
  • shoe [shoo] a foot covering; see horseshoe.

    • s. covers protective coverings for shoes worn by surgical personnel working in a sterile environment in order to minimize contamination.
  • shoeing the application of metal shoes; a universal practice in horses. Hot shoeing with shoes made by the local blacksmith has been superseded by machine made shoes fitted cold—cold shoeing. In draft cattle small shoes are applied to each claw. See also horseshoeing.

    • cold s. fitting a horseshoe without heating it in a forge and shaping it exactly to the foot.
    • s. injury includes paring too much sole, exposing sensitive laminae, nailprick of sensitive laminae, and paring too much lateral wall, causing bleeding at the white line.
  • Shohl’s solution an alkalizing solution containing citrate; previously used to correct electrolyte imbalance in the treatment of renal tubular acidosis.
  • shomer slaughterer’s assistant and stamper of the carcass in the Jewish ritual slaughter procedure.
  • Shope [shōp] named after R. E. Shope, American virologist.

    • S. fibroma see Shope rabbit fibroma.
    • S. papilloma caused by a papilloma virus and manifested by gray to black, tall, thin, horny structures on the skin of wild rabbits. The lesions may be on the head, neck, shoulders, abdomen, and inside the thighs. The disease is transmissible.

      S-52.

      

      Shorthorn dual-purpose cow.

  • short-bowel syndrome any of the malabsorption conditions resulting from massive resection or congenital absence of the small bowel, the degree and kind of malabsorption depending on the site, and extent of the missing segment; it is characterized by intractable diarrhea, steatorrhea, and malnutrition.
  • short-coupled the animal has a short coupling and therefore a compact, usually well-muscled trunk; a prized conformation in a working horse.
  • short feed see short keep.
  • short keep said of steers in a feedlot when they are expected to be fattened for 140 days or less. Called also short feed.
  • short-tailed a group of breeds of sheep characterized by naturally short tails. It includes the Heath and Marsh breeds of Europe, many Indian and Pakistani breeds, and others of the Indian subcontinent.
  • short-term behavior patterns behavior patterns that occur for short periods only, e.g., sunset and sunrise eating times, nocturnal estrus display, evening running in feedlot steers and other daily, or at shorter time intervals, activities have a considerable effect on productivity and disease wastage.
  • short thermal test for tuberculosis, subcutaneous injection of tuberculin in an animal with tuberculosis results in an abrupt hyperthermia 6–8 hours later. Occasional cows die of what appears to be an anaphylactic reaction.
  • short-woolled a class of sheep with short fleece wool, e.g., Southdown, Ryeland, Dorset Horn, the Downs sheep.
  • Shorthorn a breed of red, red-roan, white, red and white, roan and white dual-purpose cattle. Polled varieties exist. Also Dairy Shorthorn, Australian Illawarra Shorthorn, Beef Shorthorn, Milking Shorthorn.
  • shorts see pollard.
  • shot 1. lead shot; may be eaten by aquatic birds or raptors in sufficient amounts to cause lead¹ poisoning. 2. vernacular for injection.
  • shotgun hunting firearm discharging mostly round lead shot over a wide area. Associated with lead poisoning in ducks that eat the failed shot, pitch poisoning in animals that eat the residues of clay pigeons at shooting ranges, and sometimes wounds in dogs that are in the line of fire.

    • s. injuries typically occur in hunting dogs. Depending on the distance from the gun, the wounds range from extensive with much tissue damage to minor, almost undetectable, with the shot becoming imbedded in soft tissue.
    • s. pharmacy using multiple, concurrent medications to treat an animal because of uncertainty in the diagnosis. Called also polypharmacy.
    • s. procedure cloning of randomly fragmented DNA (by restriction enzyme digestion or physical methods) into vectors to form a clone library (shotgun cloning). Sequencing of these individual small DNA fragments and subsequent reassembly of the sequences based on overlaps allows the reconstruction of the original DNA sequence (shotgun sequencing). Typically used for sequencing of large genomes.
  • shotty eruption [shot′e] round, cystic papules around the tailhead and buttocks of pigs. The lesions are in sweat glands and are thought to be caused by Eimeria fusca, a protozoan parasite.
  • shoulder [shōl′d r] the simplest name for the humeral joint; the region around the large joint between the humerus and the scapula. A shallow ball-and-socket joint, similar to the hip joint. Formally called articulatio humeni.

    • s. blade scapula.
    • s. flexion a fetal postural cause of dystocia; flexion of the shoulder joint results in the affected forelimb, it may be bilateral, is lying back beside the sternum; the shoulder joint prevents entry of the fetus into the pelvic canal.
    • s. luxation uncommon in most species. Occurs most frequently in dogs and cats associated with trauma.
    • point of the s. the point over the greater tubercle of the humerus.
    • slipped s. see suprascapular paralysis.
    • s. tick see Ixodes scapularis.
  • shrew a very small, insectivorous mammal in the family Soricidae. It has a pointed nose, moderately long tail, and a very savage disposition. With over 350 species, they are distributed worldwide, apart from Australia, New Zealand, and New Guinea.

    • tree s. primitive arboreal mammal that some taxonomists place with the primates. Like squirrels in shape and size. Called also Tupaia spp.
    • s. virus a rhabdovirus with some antigenic relationship to rabies virus.
  • shrimp common name used to refer to fresh and salt water decapod crustaceans

    • sky blue s. disease see blue shell syndrome.
  • shrink in carcasses loss of weight of carcass, due to loss of fluids, from time of sale to slaughter.
  • shrinkage [shring′k j] 1. a characteristic of freshly killed meat. Weight loss occurs because of evaporation of moisture from cut surfaces. Humidity of the chilling chamber determines how much shrinkage there is. 2. loss of body weight when live animals are exposed to bad weather, deprivation of feed and water, transportation or mixing with another group.
  • Shropshire a type of English Downs sheep. It has short wool, and is used mainly for meat; it has a black-brown face and legs.
  • shuffling gait short, uncertain steps, with minimal flexion and toes dragging.
  • shunt [shunt] 1. to turn to one side; to divert; to bypass. 2. a passage or anastomosis between two natural channels, especially between blood vessels. Such structures may be formed physiologically (e.g., to bypass a thrombosis), or they may be structural anomalies. 3. a surgical anastomosis.

    • arteriovenous (A-V) s. a U-shaped or straight tube inserted between an artery and a vein (usually between the radial artery and cephalic vein), bypassing the capillary network; commonly done to allow repeated access to the arterial system for the purpose of hemodialysis.
    • cardiovascular s. an abnormality of the blood flow between the sides of the heart or between the systemic and pulmonary circulation. The direction of the flow is determined by the pressure and the outflow resistance. See left-to-right shunt (below) and right-to-left shunt (below).
    • left-to-right s. diversion of blood from the left side of the heart to the right side, or from the systemic to the pulmonary circulation through an anomalous opening such as a septal defect or patent ductus arteriosus.
    • LeVeen s. a device whose purpose is to remove excess ascitic fluid from the peritoneal cavity and return it to the venous system. Called also peritoneal-venous shunt.
    • peritoneal-venous s. see LeVeen shunt (above).
    • pleuroperitoneal s. a catheter placed to transfer pleural fluid into the peritoneal cavity; requires manual pumping.
    • portacaval s., postcaval s. see portosystemic shunt.
    • reversed s. right-to-left shunt.
    • right-to-left s. diversion of blood from the right side of the heart to the left side or from the pulmonary to the systemic circulation through an anomalous opening such as septal defect or patent ductus arteriosus.
    • ventriculoperitoneal s. a surgical procedure used in the treatment of hydrocephalus.
  • shunted blood blood that has deviated from the normal circulation, such as right-to-left or left-to-right shunts in the heart. Can result in failure of blood to be fully oxygenated. See also streamlining.
  • Shu points see association points.
  • shuttle [shut′ l] the transport of electrons or organic groups across biological membranes.

    • s. system means of transfer of reducing equivalents as NADH and H+ from the cytosol to mitochondria. The two main systems are: α-glycerophosphate shuttle and malate-aspartate shuttle.
  • shuttle pin [shut′ l] a pin for internal fixation of a fractured long bone. See also Leighton pin.
  • shuttle programs [shut′ l] programs for providing coccidiostats to poultry and avoiding breakdowns because of the development of resistance to the agent. The coccidiostat is changed during the course of a feeding program to one batch of chickens. Called also rotation programs.
  • Shwartzman phenomenon, Shwartzman reaction [shwahrts′m n] a reaction to a second dose of bacterial endotoxin. It may be a local tissue reaction characterized by thrombosis, infarction, and hemorrhagic necrosis, or generalized with disseminated intravascular coagulation and bilateral renal cortical necrosis. Called also Shwartzman-Sanarelli reaction.
  • shy timid.

    • s. breeder difficult to get pregnant because of timid disposition and disinclination to copulate.
    • s. feeder fussy, finicky eater; difficult to get to eat a full feed.
  • shying taking fright easily; said of horses that are startled easily and inclined to take a great leap sideways or to bolt with little provocation.
  • Si chemical symbol, silicon.
  • SI units the units of measurement generally accepted for all scientific and technical uses. Together they make up the International System of Units. The abbreviation SI, from the French Système International d’Unités, is used in all languages. There are seven base SI units, defined by specified physical measurements and two supplementary units. Units are derived for any other physical quantities by multiplication and division of the base and supplementary units. The derived units with special names are shown in Table 1. SI is a coherent system. This means that units are always combined without conversion factors. The derived unit of velocity is the meter per second (m/s); the derived unit of volume is the cubic meter (m³). If you know that pressure is force per unit area, then you know that the SI unit of pressure (the pascal) is the unit of force divided by the unit of area and is therefore equal to 1 newton per square meter. The metric prefixes can be attached to any unit in order to make a unit of a more convenient size. The symbol for the prefix is attached to the symbol for the unit, e.g., nanometer (nm) = 10⁻⁹ m. The units of mass are specified in terms of the gram, e.g., microgram (μg) = 10⁻⁹ kg. Only one prefix is used with a unit. The use of units such as the millimicrometer is no longer acceptable. When a unit is raised to a power, the power applies to the prefix as well, e.g., a cubic millimeter (mm³) = 10⁻⁹ m³. When a prefix is used with a ratio unit, it should be in the numerator rather than in the denominator, e.g., kilometers/second (km/s) rather than meters/millisecond (m/ms). Only prefixes denoting powers of 10³ are normally used. Hecto-, deka-, deci-, and centi- are usually attached only to the metric system units, gram, meter, and liter. Owing to the force of tradition, one noncoherent unit, the liter, equal to 10⁻³ m³ or 1 dm³, is generally accepted for use with SI. The internationally accepted abbreviation for liter is the letter l; however, this can be confused with the numeral 1 in typescript. For this reason, the capital letter L is also sometimes used as a symbol for liter. The lowercase letter is generally used with prefixes, e.g., dl, ml, fl. The symbols for all other SI units begin with a capital letter if the unit is named after a person and with a lowercase letter otherwise. The name of a unit is never capitalized.
  • Siadenovirus a genus in the family Adenoviridae that contains viruses isolated from birds, reptiles, and amphibians.
  • SIADH syndrome of inappropriate secretion of antidiuretic hormone.
  • sialadenitis [si″ l-ad″ -ni′tis] sialoadenitis.
  • sialadenosis [si″ l-ad″ -no′sis] noninflammatory swelling of the salivary glands.
  • sialagogue [si-al′ -gog] sialogogue.
  • sialectasia [si″ l-ek-ta′zh] dilatation of a salivary duct.
  • sialic [si-al′ik] 1. pertaining to saliva. 2. pertaining to sialic acid.
  • sialic acid [si-al′ik] nine carbon monosaccharide acetylated derivative of neuraminic acid; a generic term for N- and O-substituted neuraminic acids.
  • sialine [si′ -lin] pertaining to the saliva.
  • sialismus [si″ l-iz′m s] ptyalism.
  • sialisosis see mucolipidosis.
  • sialitis [si″ -li′tis] inflammation of a salivary gland or duct; in guinea pigs may be caused by a cytomegalovirus. Called also sialadenitis, sialoadenitis.
  • sial(o)- word element. [Gr.] relationship to saliva, salivary glands.
  • sialoadenectomy [si″ -lo-ad″-nek′t -me] excision of a salivary gland.
  • sialoadenitis [si″ -lo-ad″ -ni′tis] inflammation of a salivary gland.
  • sialoadenotomy [si″ -lo-ad″-not′ -me] incision of a salivary gland.
  • sialoadentitis inflammation of salivary glands.
  • sialoaerophagia [si″ -lo-ār-of′ -je] the swallowing of saliva and air.
  • sialoangiectasis [si″ -lo-an″je-ek′t -sis] dilatation of a salivary duct.
  • sialoangiitis [si″ -lo-an″je-i′tis] inflammation of a salivary duct.
  • sialoangiography [si″ -lo-an″je-og′r -fe] imaging of the ducts of the salivary glands after injection of contrast material.
  • sialocele [si′ -lo-sēl″] a salivary cyst; see salivary mucocele.
  • sialodacryoadenitis [si″ -lo-dak″re-o-ad″ -ni′tis] severe, transient inflammation of the salivary and ophthalmic glands in suckling rats caused by a coronavirus. Affected animals have exophthalmos, swelling of the face and neck, and red pigmentation around the eyes due to porphyrins excreted in the tears (chromodacryorrhea); often called ‘red tears’. There may be a secondary conjunctivitis and keratitis.
  • sialodochitis [si″ -lo-do-ki′tis] inflammation of a salivary duct.
  • sialodochoplasty [si″ -lo-do′ko-plas″te] plastic repair of a salivary duct.
  • sialoductitis [si″ -lo-d k-ti′tis] inflammation of the salivary duct.
  • sialogen an agent that induces salivation; also called sialogogue.
  • sialogenous [si″ -loj′-n s] producing saliva.
  • sialogogue [si-al′o-gog] sialagogue.
  • sialogram [si-al′o-gram] contrast image of the salivary glands.
  • sialography [si″ -log′r -fe] contrast imaging of the salivary ducts.
  • sialolith [si-al′o-lith] a salivary calculus.
  • sialolithiasis [si″ -lo-lľ-thi′ -sis] the formation of salivary calculi.
  • sialolithotomy [si″ -lo-lľ-thot′ -me] excision of a salivary calculus.
  • sialometaplasia [si″ -lo-met″-pla′zh] an uncommon disease of the mandibular salivary glands in dogs, with necrosis and squamous metaplasia of the glands, likely due to a neurogenic mechanism. There is swelling, severe pain on pharyngeal palpation or opening the mouth, dysphagia, and vomiting.
  • sialomucin [si″ -lo-mu′sin] heterogeneous group of mucopolysaccharides containing sialic acid having functions both as antiadhesive agents and as adhesion receptors.
  • sialoprotein [si″ -lo-pro′tēn] glycoproteins containing sialic acid.
  • sialorrhea [si″ -lo-re′] ptyalism.
  • sialoschesis [si″ -los′k -sis] suppression of saliva secretion.
  • sialosis [si″ -lo′sis] 1. the flow of saliva. 2. ptyalism.
  • sialostenosis [si″ -lo-st -no′sis] stenosis of a salivary duct.
  • sialosyrinx [si″ -lo-si′rinks] 1. salivary fistula. 2. a syringe for washing out the salivary ducts, or a drainage tube for the salivary ducts.
  • siamang (Symphalangus syndactylus) largest of the gibbons, native to forests of Southeast Asia; noted for its large gular sac that is inflated with air to amplify their vocalizations, called songs.
  • Siamese cat a medium-sized, svelte breed of domestic cats with blue eyes, and short hair with a distinctive pattern of pigmentation. Due to the presence of a color-limiting gene, the body is lightly pigmented while the face, ears, tail, and legs are more intensely colored. The distribution corresponds to differences in skin temperature so that only in cooler areas is pigmentation fully developed. Several color varieties exist including seal-point (dark brown), blue, lilac, chocolate, red, tabby, cream, and tortie. Siamese are also renowned for their loud, often demanding, manner of vocalizing. The breed is affected by mucopolysaccharidosis and sphingomyelinosis.

    • S. c. disease once used to refer to nutritional secondary hyperparathyroidism because of the prevalence of that disease in this breed, probably exaggerated by the popularity of the breed.
  • Siamese fighting fish a common aquarium fish. The Betta splendens, referred to as a betta fish in the aquarium trade industry, is an aggressive territorial fish so it is often housed individually.
  • Siamese twins see Siamese twins.
  • sib [sib] 1. a blood relative sharing at least one parent; one of a group of animals all descended from a common ancestor. 2. sibling.

    • half-s. see half sibling.
    • s. mating brother mated to sister.
  • Siberian 1. a handsome breed of rabbits with distinctive rollback or blanket fur that looks as though it has been shorn. Its color can be black, blue, brown or lilac; its weight is about 6 lb. 2. a breed of medium- to large-sized cat, rare outside Russia, with a long, triple coat in any color. Closely related to the Norwegian Forest cat. The national cat of Russia.
  • Siberian husky a medium-sized (35–60 lb), muscular dog with a medium-length, thick, double coat in a variety of colors and often dark markings on the head. The prominent ears are erect, and the eyes are blue or brown, often not the same, and frequently show iris heterochromia. The tail is fox brush shape and usually carried over the back. Called also Arctic husky. The breed is predisposed to corneal dystrophy, cataracts, and congenital laryngeal paralysis.
  • sibilant [sib′ľ-l nt] shrill, whistling or hissing.
  • sibling [sib′ling] any of two or more offspring of the same parents; a brother or sister.

    • half s. animals with only one parent in common, i.e., the same sire or dam.
  • sibship [sib′ship] a group of animals born of the same parents.
  • siccant [sik′ nt] 1. drying; removing moisture. 2. an agent that removes moisture.
  • siccus [sik′ s] [L.] dry.
  • Sicilian ass an Italian donkey, almost black, with pale muzzle and belly. Can be gray.
  • sick [sik] not in good health; ill; afflicted with disease.

    • s. sinus syndrome (SSS) a complex cardiac arrhythmia manifested as severe sinus bradycardia alone, sinus bradycardia alternating with tachycardia, or sinus bradycardia with atrioventricular block.
  • sickle cell a crescentic or sickle-shaped erythrocyte. In humans, the abnormal shape is caused by a structural hemoglobinopathy. Sickle cells are found in normal members of the family Cervidae (deer).
  • sickle hocks the hock joint has too acute an angle, and the foot is carried too far forward, and the metatarsus is not vertical but is inclined forward distally. It is a serious defect because of the likelihood of arthrosis in the joint.
  • sickle shin deformity of the tibia and fibula in osteoporotic primates, accompanied by pathological fractures, paraplegia, and kyphosis.
  • sickled erythrocyte see sickle cell.
  • sicklepod Sennaobtusifolia.
  • sickling [sik′ling] the development of sickle cells in the blood.
  • sickness [sik′nis] the role assumed by ill humans; not a term applicable to animals.
  • s.i.d.bis in die (once a day). Used in prescriptions and medical records to indicate the frequency of administration, once a day or every 24 hours; also abbreviated SID or q24h (preferred in prescription writing).
  • SID 1. single intradermal test for tuberculosis. 2. in radiography, sourceimage distance.
  • side [sīd] to one side.

    • s. bar see siderod.
    • s. effect see side effect.
    • s. lines a means of restraining a horse that can also be used for casting. A 60 ft cotton rope is knotted so that there is a fixed loop in the center. This is placed over the head and seated on the shoulder, and the two ends passed between the forelimbs. Each rope end is passed around a hind pastern and brought back to the shoulder loop. Pulling one of the legs up so that the hoof just reaches the ground is used as restraint to prevent the horse rearing. Pulling both legs forward causes the horse to fall.
  • side chain a group of atoms attached to the main part of a molecule that has a ring or chain structure, often referred to as −R; group that confers specific identity to compounds, particularly amino acids.
  • side-to-side anastomosis a method for establishing continuity between two blood vessels or segments of gut, whose ends have been closed. The resultant opening is wider than an end-to-end anastomosis.
  • sidebone [sīd′bōn] ossification of the alar cartilages of the third phalanx of the foot of horses. Attention is usually drawn to the disease by lameness but it is possible for the lesion to be far-advanced, and the gait to be normal. There may be obvious enlargement at the site, and the cartilages can be felt to have lost their flexibility.
  • Sideranthus North American plants in the family Asteraceae; includes S. grindeloides; facultative accumulators of selenium and can cause poisoning by selenocompounds that cause alopecia, lameness, laminitis, hoof deformity, diarrhea. Called also tansyaster, ironweed.
  • sider(o)- word element. [Gr.] relationship to iron.
  • sideroblast [sid′ r-o-blast″] a nucleated erythrocyte containing iron granules in its cytoplasm.
  • siderocalcinosis deposition of iron salts with calciumin tissues, principally blood vessels. Seen in the cerebral arteries of aged horses. Called iron ring.
  • siderochrome siderophore.
  • siderocyte [sid′ r-o-sīt″] a red blood cell containing iron-positive, focal basophilic stippling, siderotic inclusions. Seen in dogs with lead poisoning and types of hemolytic anemia.

    S-53.

    

    Bones from horse with sidebone.

  • siderod rod attached at one end to the headstall and at the other end to a roller or surcingle; it prevents a horse from biting at a hindlimb.
  • siderofibrosis [sid″ r-o-fi-bro′sis] fibrosis associated with deposits of iron.
  • sideroleukocyte [sid″ r-o-loo′ko-sīt] a neutrophil or macrophage containing hemosiderin; associated with hemolytic anemia.

    • s. test staining a smear of concentrated leukocytes with potassium ferrocyanide to demonstrate hemosiderin and ferritin. In the past, used as a general test for equine infectious anemia.
  • sideropenia [sid″ r-o-pe′ne-] deficiency of iron in the body or blood.
  • siderophil [sid′ r-o-fil″] 1. siderophilous. 2. a siderophilous cell or tissue.
  • siderophilin [sid″ r-of′ľ-lin] transferrin.
  • siderophilous [sid″ r-of′ľ-l s] tending to absorb iron.
  • siderophore [sid′ r-o-for″] a compound found secreted by bacteria and fungi that chelates iron, facilitating iron transport across the cell membrane.
  • siderosis [sid″ r-o′sis] 1. the deposit of excess iron in the tissues. 2. excess of iron in the blood.

    • hepatic s. the deposit of an abnormal quantity of iron in the liver.
    • pulmonary s. a form of pneumoconiosis due to the inhalation of iron or other metallic particles.
    • urinary s. the presence of hemosiderin granules in the urine; hemosiderinuria.
  • siderotic [sid″ r-ot′ik] emanating from or pertaining to siderosis.

    • s. nodule see Gamna–Gandy body.
    • s. pigmentation of neurons situated close to contusions and hemorrhages; caused by encrustation of the cells by basophilic complexes of iron, calcium, and phosphorus.
  • sidewheel see pace.
  • siemens (S) [se′m nz] the SI unit of conductivity, equal to one reciprocal ohm (Ω⁻¹). Called also mho.
  • Sievert (Sv) [se′v rt] the SI unit of radiation absorbed dose equivalent, defined as that producing the same biological effect in a specified tissue as 1 gray of high-energy x-rays. 1 sievert equals 100 rem.
  • sig. [L.] signa (mark); see signa.
  • sIgA secretory immunoglobulin A (IgA).
  • Sigesbeckia orientalis plant member of family Asteraceae; can cause nitrate–nitrite poisoning.
  • Siggaard-Andersen nomogram a nomogram used to determine the base excess concentration of a blood sample from its pH and Pco² values.
  • sigh [si] complementary breathing cycles characterized by a quick, deep inspiration followed by a slower expiration.
  • sight [sīt] 1. the act or faculty of vision, involving the eye itself, the optic nerve, optic tracts, optic radiations, and occipital (visual) cortex of the brain. 2. a thing seen.

    • s. hound see hound.
  • sigma the 18th letter in the Greek alphabet, Σ or σ; the former frequently denotes a standard deviation, the latter is used in mathematics for the sum of the values of the term nominated.
  • sigmoid [sig′moid] shaped like the letter C or S.

    • s. colon the distal part of the colon of some species, such as humans, shaped like an S, from the level of the iliac crest to the rectum.
    • s. curve an S-shaped curve of the relationship between two variables.
    • s. flexure of the penis situated in the bull’s penis dorsal and caudal to the scrotal neck.
  • sigmoidal kinetics the rate behavior of an enzymatic reaction that yields a sigmoid (S-shaped) curve for a plot of reaction velocity versus substrate concentration. Sigmoid kinetics are typical of allosteric enzyme-substrate systems, which have co-operative interaction.
  • sign [sīn] any objective evidence of disease or dysfunction recognizable by the veterinarian. Symptoms, the subjective sensations experienced by human patients, are not definable in veterinary medicine, and the term has no application to veterinarians.

    • cardinal s’s usually a cluster of signs that are of greatest significance to the veterinarian in establishing the identity of the illness. Key sign is a more appropriate expression for the important signs in a particular case on which the clinician will base his or her diagnosis.
    • presenting s’s the signs or group of signs about which the client complains or from which relief is sought.
    • vital s’s temperature, pulse rate, respiration rate
    • withdrawal s’s those following sudden abstinence from a drug on which a patient is dependent.
  • sign test a nonparametric statistical test based on the comparison of the signs of the differences between paired values.
  • signa [sig′n ] [L.] mark, write; abbreviated sig. in prescriptions, followed by the signature (directions to be followed by the patient [human medicine] or owner [veterinary medicine]).
  • signal 1. audible or visible indications to animals in behavioral conditioning. Many signals have had long-term use in the animal world and are used worldwide. Whoa and Getup, Heel, and Sit are common examples. Getawayback is perhaps more colloquial. Many sheepdogs are trained to react to whistles, and performing animals are usually trained to react to gestures with the hand. 2. electrochemical communication in the body; transfer of information from cell to cell and within cells.
  • s. peptidase an integral membrane protein complex located in the endoplasmic reticulum membrane that cleaves the signal peptide sequence and frees the mature protein for folding and export.
  • s. peptide short peptide sequence, usually at the N-terminal of proteins, that binds to the signal recognition particle and directs the ribosome to the endoplasmic reticulum; the peptide sequence that targets newly synthesized proteins to the correct subcellular organelles. Normally removed from the mature protein by signal peptidase. See also signal sequence.
  • s. recognition particle (SRP) a particle composed of six different proteins and one small (7S) RNA that binds to the signal peptide as it emerges from the ribosome, temporarily halting the synthesis of the protein while the complex is transported to the endoplasmic reticulum where the SRP recognizes and docks to a docking protein located on the cytoplasmic surface, followed by the transfer of the ribosome to a ribosome receptor on the membrane; the SRP and its docking protein are released from the ribosome, and translation resumes.
  • s. transduction process by which cells transduce one type of signal into another via intracellular signal transduction pathways involving enzymes and second messengers. See also cell signaling.
  • s. transduction proteins proteins involved in signal transduction.

• signal grass Brachiariabrizantha, B. decumbens.

• signal sequence see signal sequence.

• signal-to-noise ratio (SNR) in imaging, the ratio of the true signal that represents the patient, to noise that represents statistical variations in the signal. A low signal-to-noise ratio results in a poorer-quality image. Each imaging modality has its own causes and corrections for a low signal-to noise ratio.

• signaling molecules [sig′n l-ing] substances synthesized by cells for purposes of extracellular communication between cells.

• signalment [sig′n l-m nt] that part of the veterinary medical history dealing with the animal’s species, breed, age, sex.

• signature [sig′n -ch r] 1. the part of a drug prescription that gives directions to be followed by the patient, or in veterinary medicine by the animal’s owner, in its use.; (2) the veterinarian’s personal signature, followed by the abbreviations for his/her professional degrees (e.g., DVM for Doctor of Veterinary Medicine or VMD for Veterinariae Medicinae Doctoris), used on all official forms and other documents requiring the signature of the licensed veterinarian responsible for the animal’s care. 2. the veterinarian’s personal signature, followed by the abbreviations for his/her professional degrees (e.g., DVM for Doctor of Veterinary Medicine, VMD for Veterinariae Medicinae Doctoris, BVSc for Bachelor of Veterinary Science), used on all official forms and other documents requiring the signature of the licensed veterinarian responsible for the animal’s care. 3. in herbal medicine, the specific medicinal properties of a plant or plant part (root, stem/leaf, flower, fruit).

  • root s. see root signature.

• significance the quality of an assessment about the relationship between two or more values of a variable. Significance is achieved if the relationship is more common than would be achieved by a random selection.

• significant [sig-nif′ľ-k nt] said of an experimental result when it is greater than would be expected by chance. The degree of the significance can be expressed as a percentage, given the likely probability of the results occurring.

  • s. digit the number of decimal places for which the result is accurate.

• Sigurdsson vaccine a vaccine composed of killed Mycobacterium avium subspecies paratuberculosis organisms historically used in the prevention of Johne’s disease in sheep.

• Sikh slaughter a method in which conscious sheep and goats are decapitated by a single blow of a special sword; used in India. Provided a special sword is used, buffalo can be dealt with in the same way. Called also Jakta method.

• silage the major component of feeds for dairy cattle because of potentially lower harvest and storage nutrient losses and greater flexibility in feed harvesting. Green feed harvested and stored with high moisture and preserved by packing to remove oxygen and encouraging primary anaerobic fermentation to a sufficient level of acetic acid to keep a low pH. Good ensilage keeps well for several years and has high nutritive value and palatability. Some silage adjuvants (acids) or inoculants (for example, Lactobacillus bucheri) are available to encourage proper fermentation. Stored in upright sealed silos; in silage bunkers or as large piles on a concrete raft, in both cases covered with heavy mil plastic and weighed down by tires; or in large plastic tubes (tube silage) or as round bales wrapped in plastic (bale silage, wrapped silage). Called also ensilage. See also pyrexia-pruritus-hemorrhage syndrome.

  • s. density term for compactness of silage, indicative of degree of packing and elimination of oxygen.
  • s. disease see listeriosis.
  • s. eye see listeriosis.
  • s. fermentation profile laboratory analysis of fermentation quality. Usually measures the pH, titratable acidity, moisture, ammonium nitrogen; and lactic, acetic, proprionic, and butyric volatile fatty acids. Lactic acid should be the predominant VFA. Excessive acetic, proprionic, or butyric acid and ethanol indicate poor fermentation and poor-quality silage. Excessive butyric acid can result in dietary ketosis.
  • s. packing eliminates oxygen and determines silage density. Usually done with a heavy tractor in bunker silos and influenced by filling time for the bunk, packing time, weight of tractor, and particularly by forage moisture content and cut particle size (fiber length). Poorly packed silage is at greater risk for abnormal fermentation and is less stable with storage.
  • s. pH good silage quality is related to a rapid and sustained fall in pH during early anaerobic fermentation. Corn silage should have a pH of 3.5–4.2, and grass silage should be 4–4.8. High pH increases the risk for growth of Listeria spp., and high pH with a high moisture content allows clostridial fermentation and proteolysis.
  • s. poisoning. 1. overfeeding on silage may cause indigestion. Usually the result of a heavy feeding program and a shortage of hay so that the roughage supply is entirely silage. 2. a silage containing more than the usual proportion of butyric acid may predispose to ketosis. 3. silage containing a thriving population of Listeria monocytogenes may cause that disease when fed out.

• Silastic [sľ-las′tik] trademark for polymeric silicone substances having the properties of rubber; it is biologically inert and used in surgical prostheses, and Silastic tubing is used for temporary implants in tissue, e.g., for suprapalpebral irrigation of the conjunctival sac.

• sildenafil [sil-den′ -fil″] a phosphodiesterase-5 inhibitor used mainly for erectile dysfunction in humans, but its activity as an arteriolar dilator in pulmonary vasculature is utilized in the treatment of pulmonary hypertension in dogs.

• silent [si′l nt] produces no audible sound.

  • s. estrus see silent heat (below).

    S-54.

    

    Silage bunker.

    S-55.

    

    Tube silage.

  • s. heat the behavior pattern in which the animal gives no behavioral signals that an ovarian follicle is maturing and rupturing, although it is doing so or has just done so. Called also silent estrus.
  • s. lung breath sounds absent on auscultation; occurs over collapsed lung or lung shielded by fluid, pus, solid tissue.

• Siley tracheostomy tube a cuffed tube with removable inner cannula.

• silhouette [sil″ -wet′] outline of a figure. In radiology, the appearance of the silhouette is a function of the shape, size, and opacity of the object.

  • s. sign see border effacement.
• silica [sil′ľ-k ] silicon dioxide, a compound occurring naturally as quartz and in other forms. A common constituent of urinary calculi in agricultural animals, a rare occurrence in dogs.

  • s. calculi see silica urolith.
  • s. gel commonly used in the laboratory as a desiccant; has been used topically on dogs and cats for flea control.

• silicate [sil′ľ-kāt] any compound containing [SiO₄]^4- anions. Generally found in minerals.

• siliceous [sľ-lish′ s] relating to or made of silica or a silicate.

• silicon (Si) [sil′ľ-kon] a chemical element, atomic number 14, atomic weight 28.086. See also silica.

• silicone [sil′ľ-kon] any organic compound in which all or part of the carbon has been replaced by silicon. Silicones are applied to glassware used for administering blood transfusions or for collecting blood for laboratory tests based on whole blood, and are important industrial lubricants.

• silicosis [sil″ľ-ko′sis] deposits of inert dust in the lungs of animals; very rare because of lack of exposure of animals to such a polluted environment.

• silk [silk] continuous, protein filament produced by the larvae of Bombyx mori, the white silkworm moth. Used as a suture material.

• silkie docile hobby breed of poultry with atypical fluffy ‘silkie’ plumage of various colors. Popular as show chickens.

• Silkie 1. a bantam with white, curly feathers, a prominent crest of feathers, rose comb and a black skin and legs. 2. a recognized breed of guinea pig, characterized by a long, flowing coat without any rosettes.

• Silky terrier a small (8–10 lb), blue or gray with tan, silky-haired dog, larger but resembling, but larger than, a Yorkshire terrier. Called also Australian silky terrier, Sydney silky terrier.

• silo an airtight and insect-proof container used to store agricultural products, such as grain, and to make ensilage. May be made of concrete, metal, rarely of brick, or of glass-lined steel or be a hole dug in the ground, or two parallel barricades lined with plastic. Those used for grain storage need only to be insect-proof and airtight. Those used for ensilage making need also to be resistant to the corrosive effect of the acids produced during anaerobic fermentation. See also silage.

  • s. gas nitrogen dioxide.

• silo-filler’s disease pulmonary inflammation of humans, often with acute pulmonary edema, due to inhalation of the irritant gases (especially oxides of nitrogen) that collect in recently filled silos. Often quoted as a disease similar to atypical interstitial pneumonia of cattle.

• Silpha genus of the family of Silphidae of carrion beetles that infest pigeon droppings. Their larval maggots may invade the skin of live squabs.

• SILS Single Incision Laparoscopic Surgery. A technique by which laparoscopic surgery can be performed through a single small incision, rather than two or more portals.

  S-56.

  

  Grain silos.

• silver (Ag) [sil′v r] 1. a chemical element, atomic number 47, atomic weight 107.870. It is used in medicine for its caustic, astringent and antiseptic effects. Experimental poisoning with silver salts causes myopathy. 2. a coat color in dogs, foxes.

  • s. grass Aristidacontorta.
  • s. halide any of the silver salts with halogens including bromine, chlorine, iodine used in photographic emulsion.
  • s. iodide soluble silver salt used in cloud seeding but presents no toxicological risk to local grazing cattle.
  • s. nitrate colorless or white crystals, used as a caustic and local anti-infective.
  • s. nitrate (toughened) a mixture of silver nitrate with hydrochloric acid, sodium chloride or potassium nitrate, occurring as white crystalline masses molded into pencils or cones, called caustic pencils; a convenient means of applying silver nitrate locally. Called also lunar caustic.
  • s. protein silver made colloidal by the presence of, or combination with, protein; an active germicide with a local irritant and astringent effect.
  • s. weed see Potentilla anserina.

• silver dollar spots subcutaneous edematous patches up to 10 cm diameter and 1 cm thick on the skin of some horses with dourine, occurring particularly over the ribs. Present for 3–7 days and pathognomonic for the disease, but do not occur in all cases. See dourine.

• Silver fox a medium-sized (9–10 lb), commercial breed of rabbits with long, coarse black fur with silver ticking that stands out from the body.

• Silver rabbit small (5–6 lb), well-fleshed rabbit with a black, brown, or fawn coat with silvering of the tips of the hair. See also Silver fox, another breed with a similar hair coat.

• silver trevally see Pseudocaranx.

• silvex, 2,4,5-TP a weedkiller, once warranted to be safe for animals at the concentrations used to spray plants. Poisoning can be produced experimentally. Characterized by depression, anorexia, weakness especially of the hindquarters. May cause an increase in nitrate content of plants and lead to nitrite poisoning in ruminants. Use of this compound has been discontinued.

• Silverman’s needle [sil′v r-m n] an instrument for taking tissue specimens. See also Franklin–Silverman biopsy needle.

• Silybum marianum [sil′ľ-b m] plant member of the family Asteraceae; has a very high feed value but a high nitrate content. May cause nitrate–nitrite poisoning in ruminants. Its potent extract, silymarin, has found uses in herbal medicine. Called also Carduus marianus, variegated thistle, milk thistle, bull thistle, St. Mary’s thistle.

• silymarin a mixture of three compounds, silibinin, silydianin, and silychristine, extracted from milk thistle, Silybum marianum; thought to have an hepatoprotective effect and used in herbal medicine to treat liver disease.

• Simarouba amara a tree in the plant family Simaroubaceae; unidentified toxin in wood shavings has caused stomatitis and dermatitis in dogs. Called also bitter damsoe, caixeta, marupa.

• simazine [si′m -zēn] a triazine residual nonselective systemic herbicide that is toxic if livestock are allowed access shortly after the plants have been sprayed. Signs of toxicity include staggering in sheep and colic in horses. Use is banned in the European Union.

• Simbu virus group antigenically related viruses in the Bunyamwera virus group in the Bunyavirus genus; includes Akabane, Aino, Peaton, Schmallenberg, Shamonda, Shuni, and Tinaroo virus.

• simethicone [sľ-meth′ľ-kōn] an antiflatulent substance consisting of a mixture of dimethyl polysiloxanes and silica gel. Called also activated dimethicone.

• Simford an Australian breed of beef cattle produced by crossing animals of Hereford and Simmental breeds.

• simian [sim′e- n] 1. member of the infraorder Simiiformes that includes the monkeys and apes; called also ‘higher primates’. 2. ape-like.

  • s. acquired immune deficiency syndrome (SAIDS) a retrovirus-induced immune deficiency, similar to human acquired immune deficiency syndrome (AIDS).
  • s. exogenous type D retrovirus see simian acquired immune deficiency syndrome (above).
  • s. hemorrhagic fever a highly fatal disease of macaques, caused by certain arteriviruses. It is characterized by edema, hemorrhages, and diarrhea.
• Simmental dual-purpose Swiss cattle, reddish dun or yellow and white in color. There are many varieties throughout Europe. Black Simmental is a black variant.

  • S. hereditary thrombopathy see hereditary thrombocytopathy.

    S-57.

    

    Simmental dairy cow.

  • Simmonds’ disease [zim′ ndz] panhypopituitarism in which cachexia is a prominent feature; called also pituitary cachexia. It follows the destruction of the pituitary gland by surgery, infection, injury or tumor.
  • Simmondsia chinensis a shrub in the plant family Simmondsiaceae; oil is extracted from its fruit; the meal resulting from oil extraction if fed to breeder chickens interferes with normal maturation of oviducts causing complete absence of egg production. Called also jojoba, goat nut, pig nut.
  • Simondsia paradoxa member of the nematode family Thelaziidae. A stomach worm of pigs. Causes chronic gastritis but unlikely to have any effect except perhaps to reduce growth rate.
  • Simonsiella muelleri gram-negative bacteria that form very long, flat filaments (up to 1 mm in length). Common, nonpathogenic inhabitant of mouths of animals.
  • simplexin diterpenoid daphnane ester responsible for toxic affects of Pimelea spp.
  • Simplexvirus [sim′pleks-vi″r s] a genus in the subfamily Alphaherpesvirinae that has 11 species and includes human herpes simplex viruses 1 and 2 and bovine herpesvirus 2.
  • simuland characteristic of a real life system.
  • simular characteristic of a simulation model.
  • simulation [sim″u-la′sh n] 1. imitation of a system such as an ecological or farming system by a series of mathematical formulae. 2. the act of running a model. 3. the imitation of one disease by another.

    • s. model mathematical models of dynamic processes that include combinations of mathematical and logical processes. They are generally used to compare several solutions to a problem.
  • simulid see Simulium.
  • Simulium [si-mu′le- m] a large genus of insects in the family Simuliidae causing ‘insect worry’ with livestock. Cutaneous lesions may include vesicles and wart-like papules, and edema and petechiation of thinskinned, ventral areas. Poultry may be affected by anemia. The species also transmits a number of animal diseases including the viruses of vesicular stomatitis and eastern equine encephalomyelitis, the protozoans, Leucocytozoon and Haemoproteus spp., and are intermediate parasites for some Onchocerca spp. Also called black flies and buffalo gnats.
  • SIMV synchronized intermittent mandatory ventilation.
  • sinalbin [sin-al′bin] the glycoside in the seeds of white mustard (Sinapis alba) that is converted to isopropyl isothiocyanate and sinapine sulfate that can cause gastroenteritis manifested by abdominal pain and diarrhea.
  • sinapine sulfate one of the toxic agents produced by the metabolism of sinalbin, a glycoside in mustard seed.
  • Sinapis [sin′ -pis] plant genus in the family Brassicaceae. The mustards. Cause poisoning due to sinalbin, sinigrin, mustard oil glucosinolates concentrated in the seeds, poisoning manifested by abdominal pain and diarrhea. Foliage can also cause nitrate–nitrite poisoning. Includes S. alba (white mustard, commercial mustard Brassica hirta), S. arvensis (B. kaber, wild mustard, charlock—a common weed of cultivation).
  • sinciput [sin′sľ-p t] the upper and front part of the head; the forehead.
  • Sinclair miniature swine developed in Minnesota, US, specifically for the purpose of research.
  • sinew [sin′u] a tendon of a muscle.
  • Singapura a native cat of Singapore; a small cat with a short sepia agouti coat with dark brown ticking. The eyes are hazel, green, or yellow. In Singapore, recognized as a living national treasure.
  • singeing flash application of flame to remove residual, esthetically unattractive hairs from poultry and pig carcasses.
  • Singer–Nicolson membrane model major current model of membrane structure. Incorporates a fluid mosaic structure whose major features include a discontinuous lipid bilayer composed predominantly of phospholipids, and proteins (often glycoproteins) that are integral to the structure, and peripheral proteins that are not essential to reassembly of a functional membrane.
  • Singhfilaria hayesi a filarioid, tissue-dwelling nematode found in tissues around the crop and trachea of quail, turkeys in the US. Not considered to be pathogenic.
  • single-blind study see blinding.
  • single-foot a fast, four-beat walking gait, short of a trot. Only one foot is on the ground at a time. See also broken amble.
  • singultus [sing-gul′t s] hiccup.
  • sinigrin [sin′ľ-grin] a toxic glycoside in the seed of Sinapis nigra (black mustard). Converted by the enzyme myrosin to allylisothiocyanate, the volatile oil of mustard.
  • sinister [sľ-nis′t r] [L.] left; on the left side.
  • sinistrad [sľ-nis′trad] to or toward the left.
  • sinistral [sin′is-tr l] pertaining to the left side.
  • sinistr(o)- word element. [L.] left, left side.
  • sinistrocardia [sin″is-tro-kahr′de- ] left sided intrathoracic position of the heart. see levocardia.
  • sinistrocerebral [sin″is-tro-ser′ -br l] situated in the left hemisphere of the brain.
  • sinistrogyration [sin″is-tro-ji-ra′sh n] a turning to the left.
  • sinistrotorsion [sin″is-tro-tor′sh n] a twisting toward the left, as of the eye.
  • sinker syndrome a severe form of laminitis in horses; refers to ventral or downward displacement of the distal phalanx in the hoof, detected on radiographic examination. A sign of poor prognosis. See also pedal bone rotation.
  • sinoatrial (S-A, SA) [si″no-a′tre- l] pertaining to the sinus venosus and the atrium of the heart or to the sinoatrial node.

    • s. block a delay or disruption in the initiation of an action potential within the AV node and atrial depolarization, such that there is no P wave on a surface electrocardiogram. Also called exit block.
    • s. node an anatomically and electrophysiologically heterogeneous structure that expresses a unique set of ion channels necessary for the generation and propagation of an action potential that then sets the atrial and ventricular rates in health. Located in the wall of the right atrium, adjacent to the sulcus terminalis. Referred to as the pacemaker of the heart. Called also sinoatrial bundle, Keith’s node, Keith–Flack node.
  • sinography [si-nog′r -fe] imaging of a sinus tract using a contrast medium.
  • Sinostrongylus see Caballonema.
  • sinuotomy sinusotomy.
  • sinuous [sin′u- s] bending in and out; winding.
  • sinus [si′n s] 1. a recess, cavity, or channel, as (a) one in bone or (b) a dilated, valveless channel for venous blood. 2. an abnormal channel or fistula, permitting escape of pus. In common, unqualified usage, the word sinus refers to any of the cavities in the skull that are connected with the nasal cavity—the paranasal sinuses.

    • anal s’s furrows, with pouchlike recesses at their distal ends, separating the rectal columns; called also anal crypts.
    • basilar s. a dural venous sinus that runs on the floor of the cranial cavity and out through the foramen magnum.
    • blood s. see blood sinus.
    • carotid s. the slightly dilated portion of the internal carotid artery found near the subdivision of the common carotid into its two main branches and that contains baroreceptors innervated by a branch of the glossopharyngeal nerve (Hering’s nerve).
    • cavernous s. an irregularly shaped venous channel between the layers of dura mater of the brain, one on either side of the body of the sphenoid bone and communicating across the midline. Several cranial nerves and, when present, the rete mirabile, course through this sinus.
    • cavernous s. syndrome syndrome characterized by deficits in more than one of the cranial nerves that traverse the cavernous sinus at the base of the cranial vault: cranial nerve III (oculomotor), IV (trochlear), VI (abducens), and the first two branches of cranial nerve V (trigeminal). Clinical signs include ophthalmoplegia, mydriasis, ptosis and partial loss of sensation around the face. Vision is usually spared.
    • cerebral s. one of the ventricles of the brain.
    • cervical s. a temporary depression in the neck of the embryo containing the branchial arches.
    • circular s. the venous channel encircling the pituitary gland, formed by the two cavernous sinuses and the anterior and posterior intercavernous sinuses.
    • conchal s. cavity of the conchal bone.
    • coronary s. the terminal portion of the great cardiac vein, which lies in the cardiac sulcus between the left atrium and ventricle, and finally empties into the right atrium.
    • dermoid s., dermal s. see dermoid sinus.
    • dorsal sagittal s. a large dural venous sinus located within the falx cerebri.
    • dura mater venous s. large channels for venous blood forming an anastomosing system between the layers of the dura mater of the brain.
    • ethmoidal s. that paranasal sinus consisting of the ethmoidal cells collectively, and communicating with the nasal meatuses.
    • facial s. see malar abscess.
    • frontal s. one of the paired paranasal sinuses in the frontal bone, each communicating with the middle meatus of the ipsilateral nasal cavity.
    • hair s. see sinus hair.
    • infraorbital s. 1. an air-filled recess in the head of birds that lies lateral to the nasal cavity into which it opens. 2. the cutaneous pouch below the eye of sheep and some other ruminants. Called also sinus infraorbitali.
    • intercavernous s. channels connecting the two cavernous sinuses, one passing anterior and the other posterior to the stalk of the pituitary gland.
    • interdigitalis s. the cutaneous pouch that lies between the claws of sheep and some other ruminants and whose wall contains apocrine glands, and whose duct discharges onto the skin just above the coronets; it serves as a trail gland. Called also sinus interdigitalis.
    • lymphatic s. irregular, tortuous spaces within lymphoid tissues through which lymph flows.
    • maxillary s. one of the paired paranasal sinuses in the body of the maxilla on either side, opening into the middle meatus of the ipsilateral nasal cavity. In the horse it is divided into two compartments that communicate independently with the nasal chambers. All other sinuses of the horse communicate with the nasal chambers via the caudal maxillary sinus.
    • nasal s. see paranasal sinuses (below).
    • s. nerve a branch of the glossopharyngeal nerve; carries the afferent fibers of the stretch receptors in the wall of the carotid sinus.
    • s. node see sinoatrial node.
    • occipital s. a venous sinus between the layers of dura mater, passing along the midline of the cerebellum.
    • paranasal s’s mucosa-lined air cavities in bones of the skull, communicating with the nasal cavity and including ethmoidal, frontal, maxillary, and sphenoidal sinuses.
    • petrosal s. (inferior) a venous channel arising from the cavernous sinus and draining into the internal jugular vein.
    • petrosal s. (superior) one arising from the cavernous sinus and draining into the transverse sinus of the dura mater.
    • prostatic s. the dorsolateral recess between the seminal colliculus and the wall of the urethra.
    • pulmonary trunk s. any one of the three dilations of the pulmonary trunk at its origin from the right ventricle, adjacent to each of the cusps of the pulmonary valve.
    • red pulp s. vascular storage in the spleen into which capillaries empty.
    • s. reflex arc afferent fibers are in the sinus nerve; these connect with the cardioinhibitory and vasomotor centers that control blood pressure and heart rate via sympathetic fibers to blood vessels; provides a route for the sinus reflex that relates pressure in the carotid sinus to the performance of the circulatory system.
    • renal s. a recess in the substance of the kidney, free from renal parenchyma that is occupied by the renal pelvis, calices, vessels, nerves, and fat.
    • sagittal s. (inferior) a small venous sinus of the dura mater of large animals found between the cerebral hemispheres and opening into the straight sinus.
    • sagittal s. (superior) a venous sinus of the dura mater that courses between the cerebral hemispheres and ends in the confluence of sinuses.
    • scleral venous s. see Schlemm’s canal.
    • sigmoid s. a venous sinus of the dura mater on either side, continuous with the straight sinus and draining into the internal jugular vein of the same side.
    • sphenoidal s. one of the paired paranasal sinuses in the body of the sphenoid bone of some species. In the horse it communicates with the nasal cavity via the frontal and caudal maxillary sinuses.
    • sphenoparietal s. one of the venous sinuses of the dura mater, emptying into the cavernous sinus.
    • splenic s. dilated venous channels in the substance of the spleen. See also red pulp sinus (above).
    • straight s. a venous sinus of the dura mater formed by junction of the great cerebral vein and inferior sagittal sinus, and ending in the confluence of sinuses.
    • suture s. caused by the presence of a suture; due to epithelial ingrowth into a skin suture tract, or infection around a buried suture.
    • tarsal s. a space between the calcaneus and talus.
    • tentorial s. straight sinus.
    • tonsillar s. the single opening of a compound follicle of a tonsil, as occurs in the palatine tonsil of cattle.
    • transverse dura mater s. a large venous sinus that runs in the attached border of the cerebellar tentorium on either side of the skull.
    • transverse pericardial s. a passage within the pericardial sac, between the aorta and pulmonary trunk cranioventrally, and the left atrium and cranial vena cava dorsally.
    • tympanic s. a deep recess on the medial wall of the middle ear.
    • urachal s. an anomalous closure of the urachal canal in the newborn in which the opening at the umbilicus remains open. The bladder is normal. It is the cause of persistent infection and swelling at the umbilicus in the young animal and may lead to cystitis and pyelonephritis.
    • urethral s a small cavity in the glans penis of the horse, above the urethral process; as a recess of the fossa glandis it is usually filled with a small mass (the so-called ‘bean’) of inspissated smegma.
    • urogenital s. an elongated sac formed by division of the cloaca in the early embryo, which ultimately forms the vestibule in the female, part of the urethra, as well as the prostate and bulbourethral glands in the male, and the bladder in both sexes.
    • uterine s. venous channels in the wall of the uterus in pregnancy.
    • uteroplacental s. blood spaces between the placenta and uterine sinuses.
    • s. venarum a smooth-walled chamber that makes up the greater part of the right atrium, lying between the orifices of the great veins.
    • venous s., s. venosus 1. the common venous receptacle in the heart of the early embryo that receives blood from the umbilical and vitelline veins and from the body via the ducts of Cuvier. 2. sinus of venae cavae.
    • vertebral s. a continuation of part of the common occipital vein in birds; it emerges from the foramen magnum and accompanies the vertebral vein.
  • sinusitis [si″n s-i′tis] inflammation of one or more of the paranasal sinuses, often occurring during an upper respiratory infection, by extension from the nasal cavity. Sinusitis also may be a complication of tooth infection, allergy, or certain infectious diseases. It is most common in horses and cats, in cattle it is usually a complication of dehorning, and in dogs it often results from intranasal foreign bodies. In its chronic form it is characterized by a continuous or intermittent discharge of pus through the nostril on the affected side or through a sinus to the exterior. See also sinus.

    • infectious s. of turkeys caused by Mycoplasma gallisepticum and characterized by swelling of the infraorbital sinuses that are filled with thick pus. Some cases also have airsacculitis and conjunctivitis.
  • sinusography sinography.
  • sinusoid [si′n -soid] 1. resembling a sinus. 2. a form of terminal blood channel consisting of a large, irregular, anastomosing vessel, having a lining of reticuloendothelium but little or no adventitia. Sinusoids are found in the liver, adrenal glands, heart, parathyroid glands, carotid bodies, spleen, hemolymph glands, and pancreas.
  • sinusotomy [si″n -sot′ -me] incision of a sinus.
  • siphon [si′f n] 1. a bent tube with arms of unequal length, for drawing liquid from a higher to a lower level by force of atmospheric pressure. 2. to draw liquid by means of a siphon.
  • Siphona see Haematobia.
  • siphonage [si′fon- j] the use of the siphon, as in gastric lavage or in draining the bladder.
  • Siphonaptera [si″fo-nap′t r-] the order of fleas, a group of wingless parasitic insects that feed on the blood of vertebrate hosts.
  • sire male parent.

    • confirmed s. one that has been proven to have good fertility.
    • s. evaluation in farm animals, the estimation of the breeding value of a male by progeny testing.
    • s.-family average the average performance of the half-sib family of which the individual is a member.
    • s. line characteristics contributed to the offspring of a cross mating by the sire.
    • terminal s. one used in a crossbreeding system where both male and female progeny are marketed.
    • s. verification verifying that a stated sire is indeed a parent by the use of a paternity testing technique.
  • sirenian aquatic herbivorous mammal member of the order Sirenia; includes the sea-cow (now extinct), manatee, and dugong.
  • sirenomelus [si″r n-om′-l s] a fetus with fused legs and no feet.
  • sires of dams pathway breeding pattern for selecting sires who will be expected to produce good dams.
  • sires of sires pathway breeding pattern for selecting sires who will be expected to produce good sires.
  • siresine a type of harness worn over the forequarters by rams and as a headstall in bulls in mating groups. The harness carries a crayon on the brisket or under the chin in bulls so that females that are mounted by the male are marked by the crayon. Different colored crayons are used to identify females mated over a particular period of time or by individual males. This identifies the sire when more than one male is in the group.
  • SIRM sterile insect release method.
  • SIRS systemic inflammatory response syndrome. A generalized inflammatory response with vasodilation of capillaries and postcapillary venules, increased permeability of capillaries, and hypovolemia. Depressed cardiac function and decreased organ perfusion follow. The various initiating stimuli include sepsis and septic shock, hyperthermia, pancreatitis, trauma, snake bite, and immune-mediated diseases. In dogs and cats, diagnosis requires two of the following four abnormalities: tachycardia, tachypnea, abnormal body temperature, and abnormal total white cell count or >5% bands on a hemogram.
  • -sis word element. [Gr.] state, condition.
  • sisomicin [sis″o-mi′sin] an aminoglycoside antibiotic similar to gentamicin produced by cultures of Micromonospora inyoensis. Called also sisomycin, sissomicin.
  • Sistrunk scissors [sis′tr nk] short dissecting scissors.
  • Sisymbrium irio a plant in the family Brassicaceae capable of causing severe gastroenteritis and sulfur-associated polioencephalomalacia in cattle. Called also London rocket.
  • Sisyrinchium plant genus in the Iridaceae family, suspected to contain a cardiac glycoside that causes violent diarrhea in livestock. Includes S. iridifolium, S. micranthum, S. platense. Called also scour weed, yellow rush lily.
  • sit-fast see set-fast.
  • sitatunga (Tragelaphus spekii) a medium-sized, semi-aquatic African antelope with spreading feet adapted to marshy ground. Called also marshbuck.
  • sitiology, sitology the science of food and nourishment.
  • sitotropism [si-tot′ro-piz- m] tropism in response to the influence of food.
  • situs [si′t s] pl. situs [L.] site or position.

    • s. inversus total or partial transposition of the body organs to the side opposite the normal.
    • s. solitus normal position of the thoracic and abdominal organs.
  • Sium plant genus in the family Apiaceae; contain an unidentified toxin that causes several syndromes: (1) abdominal pain and diarrhea, (2) tremor, convulsions, bloat, bradycardia, and (3) taints milk; includes S. angustifolium (cow-cress, fool’s watercress), S. latifolium (water parsnip), S. suave (S. cicutaefolium).
  • six-minute walk test a measure of a dog’s submaximal exercise tolerance by measuring the distance walked in a 6-minute period, used to evaluate severity of cardiac, respiratory, and muscular diseases and to assess response to treatment.
  • six tooth in sheep, a 3-year-old with all six permanent incisor teeth erupted.

    S-58.

    

    Siresine harness.

  • size a criterion of growth other than height and weight; a combination of height, depth, width, and weight. A large animal is tall but deep and wide in proportion; all of its dimensions are large.
  • Sjögren syndrome [shur′gren] an immune-mediated disorder marked by keratoconjunctivitis sicca and xerostomia, often occurring in association with other inflammatory disorders such as immune-mediated arthritis and systemic lupus erythematosus. Reported in dogs.
  • SK streptokinase.
  • skatole [skat′ōl] 3-methylindole, a derivative of tryptophan formed in the putrefaction of proteins and in the mammalian digestive tract that contributes to the characteristic odor of the feces.
  • skatoxyl [sk -tok′sil] an oxidation product of skatole formed in the large intestine in certain diseases and excreted in the urine.
  • skeletal [skel′ -t l] pertaining to the skeleton. See also skeletal muscle.

    • s. remodeling the continuous dynamic process of resorption of some parts of the bony skeleton and mineralization of others.
    • s. scurvy see hypertrophic osteodystrophy.
    • s. system the body’s framework of bones and associated cartilages; see also skeleton.
    • s. tissue the bony, ligamentous, fibrous, and cartilaginous tissue forming the supporting framework of the animal body.
  • skeletal patterning [skel′ -t l] development of the limb primordia, pairs of limb buds, or other skeletal primordia, in the correct relationship to each other and to surrounding structures.
  • skeletization [skel″ -tľ-za′sh n] 1. extreme emaciation. 2. removal of soft parts from the skeleton.
  • skeletogenous [skel″ -toj′-n s] producing skeletal structures or tissues.
  • skeleton [skel′ -t n] the stiff, hardened tissues forming the supporting framework of an animal body.

    • appendicular s. the bones of the limbs.
    • axial s. the skull, spine, ribs, and sternum.
    • visceral s. 1. the skeleton that forms part of an organ such as the os penis or os cordis. 2. (rare) the bony framework that protects the viscera, such as the sternum, ribs, or pelvis.
    • s. weed see Lygodesmia.
  • skeocytosis the presence of immature forms of leukocytes in the blood; shift to the left.
  • skewbald a horse coat color of mostly white with some large, irregular patches of any other color than black.
  • skewed curve of a usually unimodal distribution with one tail drawn out more than the other, and the median will lie above or below the mean.
  • ski jump in radiographs, an appearance of enlarged caudal epiphyses of cervical vertebrae, which may encroach on the vertebral canal, causing compression of the spinal cord. Ski jump sign.
  • skia- word element. [Gr.] shadow (especially as produced by x-rays).
  • skiagraph radiograph.
  • skiametry [ski-am′ -tre] see retinoscopy.
  • skiascope [ski′ -skōp] an instrument that measures the refractive status of the eye, more commonly termed retinoscope.
  • skim milk the residue from whole milk after the cream has been skimmed off. In today’s usage, it is the residue after the butterfat is removed.

    • s. m. extender skim milk used as a diluent for semen. See also semen extender.
    • s. m. powder dehydrated skim milk used extensively as a milk replacer provided it is not too expensive. A high-protein supplement but deficient in vitamins A and D, both of which will have been extracted with the butterfat.
  • skin [skin] the outer covering and largest organ of the body. It is made up of two layers (dermis and epidermis) that are developmentally and functionally distinct. It serves as a protective barrier against microorganisms, helps shield delicate tissues underneath from mechanical and other injuries, insulates against heat and cold, and helps eliminate body wastes. It guards against ultraviolet radiation by producing a protective pigment, and it helps produce vitamin D. Its sense receptors detect pain, cold, heat, touch, and pressure. The skin consists of an outer cellular, avascular epidermis, and an inner fibrous corium (dermis, true skin) resting upon a hypodermis of fat and panniculus muscle. See also cutaneous, epidermal, epidermis.

    • s. appendages see hair, claw, hoof, horn, chestnut (1), ergot², dewclaw, comb, wattle¹, spur (3), pad, footpad, beak, feather (1), cere, scale, fin, antler, bristle (1), wool, mohair, cashmere, Angora.
  • s.-associated lymphoid tissues (SALT) see skin-associated lymphoid tissue.
  • autoimmune s. disease see autoimmune, pemphigus, lupus erythematosus.

    S-59.

    

    Structure of mammalian skin.

  • s. biopsy removal of a small section of skin for histopathological examination.
  • s. cancer lay term that includes any epithelial neoplasm of skin, either benign or malignant.
  • congenital absence of s. see epitheliogenesis imperfecta.
  • s. depigmentation see hypopigmentation.
  • s. emphysema see subcutaneous emphysema.
  • s. fold thickness a measure of obesity in humans but not a valid indicator in dogs or cats as the skin lifts off the subcutaneous tissue.
  • s. fungal infection see dermatomycosis, dermatophytosis.
  • s. gangrene death of tissue and usually involves dermis, epidermis and subcutaneous tissue, e.g., severe saddle galls, heat burns, chemical burns, Claviceps purpurea poisoning. The affected area is cold and bluish in color. This changes to black, and the area begins to lift at the edges and to dry out.
  • s. inflammation see dermatitis.
  • s. leukosis occurs in Marek’s disease. Called also cutaneous lymphosarcoma.
  • s. receptor cutaneous sensory endorgans.
  • s. resiliency test see skin tenting test (below).
  • s. scraping a scraping of the superficial elements of the skin for laboratory examination for parasitic and fungal elements.
  • s. tag see fibrovascular papilloma.
  • s. tension lines see tension line.
  • s. tenting test a fold of skin is picked up and then quickly let go. The amount that it will stretch is an indication of its extensibility. The speed with which it returns to a normal position is determined by the degree of hydration of the skin and subcutaneous tissue and the amount of fat in the subcutaneous tissue, e.g., in an animal that is 10–12% dehydrated the skin fold will not disappear until 20–45 seconds have elapsed.
  • s. test application or intradermal injection of a substance to the skin to test the body’s reaction to it. Such a test detects an animal’s sensitivity to such allergens as dust, pollen, parasites, or microorganisms believed to be the cause of a disorder. There are several types of skin tests, including the patch test, the scratch test, and the intradermal test.

    S-60.

    

    Intradermal allergy skin test.

  • skink member of the very large and diverse Scincidae family of lizards. They have an elongated body and long tails; some species have no limbs. Popular as pets. The blue-tongued skink (Tiliqua scincoides) is called the blue-tongued lizard in Australia where it is commonly kept as a pet.
  • Skinner box [skin′ r] an experimental enclosure for testing animal conditioning, in which the subject animal performs (e.g., presses a bar or lever) to obtain a reward. See also instrumental conditioning.
  • skippers larvae of Piophila casei, the cheese or ham fly. The larvae skip around on the cheese that they inhabit and are so named due to their unique ability to launch themselves into the air.
  • Skirrow’s medium a blood agar base suitable for growing Campylobacter fetus and Brucella spp.
  • skirt abattoir term for diaphragm.
  • skirtings untidy pieces of inferior-quality wool from the edges of a fleece. They are removed and sold separately.
  • Sklar forceps rack a flat plate with stand-up pins. The hemostats are laid on the plate with the finger grips over two of the pins and the blades positioned between two others. Suitable for compact, tidy transport, and storage of large numbers of hemostats.
  • skler(o)- for words beginning thus, see those beginning scler(o)-.
  • skot(o)- see scot(o)-.
  • Skrjabinagia a genus of worms in the subfamily Ostertagiinae and the family Trichostrongylidae found in ruminants, primarily in deer (cervids). The taxonomy of this group is contentious, and Skrjabinagia is currently treated by most authors as a synonym of Spiculopteragia.
  • Skrjabinema a genus of nematodes in the family Oxyuridae. They inhabit the ceca of ruminants. Includes S. africana (steinbock in Africa), S. alata (sheep), S. caprae (goats), S. ovis (sheep, goat, and antelope), S. tarandi (reindeer and caribou).
  • Skrjabingylus a genus of worms in the metastrongyloid family Skrjabingylidae found in the nasal sinuses of their hosts. Includes S. chitwoodorum (skunks), S. magnus (skunks), S. nasicola (mink, polecat and fox), S. petrowi (pine marten), and S. santaceciliae (hooded skunks).
  • Skrjabinoptera a genus of physalopterid nematodes (roundworms) found in the stomachs of lizards.
  • Skrjabinotrema ovis a digenetic trematode in the family Hasstilesiidae; found in the small intestine of sheep.
  • skull [skul] the bony framework of the head consisting of two parts, the cranium and the facial section. The cranium is the domed top, back, and sides of the skull that protects the brain. It is made up mostly of a roof of flat membrane bones united by sutures in the young, plus a series of cartilage bones at the base (occipital, sphenoid). Paranasal sinuses variably excavate the membrane bones. The facial bones are mostly membrane bones and serve to support the dental arcades and the respiratory passages of the head.

    • s. bones the bones of the skull are the basisphenoid, ethmoid, frontal, incisive, interparietal, lacrimal, nasal, occipital, nasal conchal, palatine, parietal, presphenoid, pterygoid, sphenoid, temporal, vomer, and zygomatic. Most of these are paired although a few are single. Although the three ear ossicles on each side are found within the temporal bone, they are usually not included as members of the skull bones. Neither is the mandible nor the hyoid bones (see separate entries for these bones).
    • brachycephalic s. short, broad skull; see brachycephalic.
    • dolichocephalic s. long, narrow skull; see dolichocephalic.
    • mesaticephalic s. a medium skull in terms of width and length; see mesaticephalic.
  • skunk a musteline mammal of the family Mephitidae. The best-known animal in this group is the striped skunk, Mephitis mephitis, a cat-size, mostly nocturnal, burrowing animal with a beautiful black coat and two longitudinal white stripes that run into the tail; kept as a pet in some countries. It can also eject a powerfully pungent foul-smelling liquid from the anal scent glands up to 10 ft through the air. An important vector for rabies.

    • s. cabbage see Lysichiton americanus, Symplocarpus foetidus, Veratrum californicum.
    • s. descenting see descenting.
    • s. rabies skunks are an important reservoir host of rabies in North America where they are a common source of rabies in cattle.
  • Skye terrier a small (25 lb) dog with a distinctive appearance—the body is very long (the total length is specified in the breed standard as 41 in.) and the legs are very short (height 10 in.). The long, gray, fawn, cream, or black coat is flat and straight, covering the face. There are prick- or drop-eared types. The breed is affected by an inherited laryngeal hypoplasia. Identified as a Vulnerable Native Breed in the UK.

    S-61.

    

    The three basic shapes of the dog skull seen in common breeds, showing the maxillary and frontal sinuses. Aspinall, V., Cappello, M. Introduction to Veterinary Anatomy and Physiology Textbook, 3rd ed. Butterworth-Heinemann, 2015.

    S-62.

    

    Skunk. Courtesy of CDC.

  • skyline view tangential radiographic view of any structure; taken to provide more information than the standard projections. Used to examine the trochlear groove of the stifle in dogs and carpal slab fractures in horses.
  • slack loose; not taut.
  • s. cap a can of meat with one of the ends bulging slightly indicating the beginnings of a blown can.
  • Slackia heliotrinireducens a coccoid gram-positive anaerobic ruminal organism thought to detoxify pyrrolizidine alkaloids in the rumen of sheep.
  • slaframine [slaf′r -mēn] the sialagogic indolizidine alkaliodal mycotoxin in the fungus Rhizoctonia leguminicola.
  • slag vitreous residue after removal of metal in a smelting process.

    • basic s. a by-product of the smelting industry, basic slag is used as a fertilizer. Animals pastured on recently heavily dressed fields may be affected by colic, diarrhea, and posterior paresis. The specific cause of the poisoning is not known but it is probably multi-factorial as slag can contain many hazardous heavy metals/metalloids and anions.
  • slaked lime unslaked lime (calcium oxide) to which water has been added. Called also calcium hydroxide. See also lime water.
  • slap test see laryngeal adductory reflex.
  • slatted floor wooden, plastic or metal floors with narrow gaps between slats to permit discharge of feces and urine to the external environment, e.g., in a shearing shed, or into a cesspit, the common construction on farms in the northern hemisphere. They are labor-saving but can cause serious damage to feet and limbs if not constructed carefully.
  • slaughter 1. the killing of animals for the preparation of meat for human consumption. Many methods are used. See also emergency slaughter, captive bolt pistol, carbon dioxide anesthesia, Jewish slaughter, Muslim slaughter, pithing, puntilla, shechita, Sikh slaughter. 2. destruction of animals because they are diseased, e.g., in test-and-slaughter culling programs.

    • casualty s. see emergency slaughter.
    • Danish s. data system a detailed system for keeping data on slaughter and meat inspection of pigs in Denmark. Based on tattooing of all pigs and a code for meat inspection findings with all information stored on a computer system.
    • s. hall, s. floor the part of an abattoir in which the slaughtering is conducted.
    • selective s. slaughter and disposal of infected animals as a tool in the eradication of disease. Those slaughtered may be infected or be positive reactors or in-contact animals.
    • s. spleen enlargement and congestion of the spleen with hemorrhages under the capsule that occur in some slaughter methods.
    • stunning–bleeding s. stunning either with a hammer or by electric shock followed by shackling and lifting, then by opening of the jugular vein.
  • slaughterhouse abattoir.

    • s. data data on lesions found in carcasses at abattoir.
  • SLE systemic lupus erythematosus.
  • sleep [slēp] a period of rest during which volition and consciousness are in partial or complete abeyance and the bodily functions partially suspended; a behavioral state marked by characteristic immobile posture and diminished but readily reversible sensitivity to external stimuli.

    • s. deprivation caused in animals by constant stimulation, e.g., preventing them from lying down, is followed by a compensatory period of prolonged sleep whenever the opportunity arises.
    • s. disorders see narcolepsy, cataplexy.
    • put to s. a common euphemism for euthanasia.
    • rapid eye movement (REM) s. that type of sleep characterized by low voltage but fast electroencephalographic activity and little muscular activity except of the ocular muscles. Believed to be the critical or necessary component of sleep. Called also ‘sleep of the body’ and paradoxical sleep. Called also REM.
  • sleeper foal syndrome newborn foals with systemic inflammatory syndrome secondary to septicemia, severe toxemia, or hypovolemia or anemia and characterized by recumbency, sagging posture, lack of interest in food or the dam, listlessness to the point of coma.
  • sleeper syndrome see hemophilosis.
  • sleeping disease narcolepsy.

    • s. d. syndrome disease affecting freshwater farmed fish, mainly rainbow trout; characterized by lethargy and immobility; thought to be caused by Salmonid alphavirus; Also called pancreas disease.
  • sleeping sickness any disease characterized by drowsiness or somnolence. See also pregnancy toxemia (1) of ewes, equine viral encephalomyelitis, Cryptobia cyprini, trypanosomiasis.
  • sleepy characterized by sleep.

    • s. foal disease see Actinobacillus equuli septicemia.
    • s. staggers see hepatic encephalopathy.
  • sleepygrass [sle′pe-gras] see Stipa
  • sleeve dog another name for the Pekingese dog; so-called because they were carried in the sleeve of robes worn by Chinese royalty.
  • slicker brush see carder.
  • slide [slīd] a piece of glass or other transparent substance on which material is placed for examination under the microscope.

    • s. culture technique a rapid method of preparing fungal colonies for examination and identification.
  • sliders aquatic turtles from the genus Trachemys, native to the Americas. Commonly kept as pets, especially the red-eared slider (T. scripta elegans); all are prohibited in Australia.
  • sliding filament model mechanism proposed for muscle contraction where myosin head groups of the thick filaments move along the interdigitated actin of the thin filaments, sliding past them, and thereby shortening the sarcomere.
  • slime balls form in which the cercariae of Dicrocoelium dendriticum are discharged from the intermediate host snail; cercariae become infective only if the next intermediate stage, the ant, ingests the slime ball.
  • sling [sling] suspensory for supporting a part.

    • body s. canvas and metal sling for support of the abdomen with breastplate and breeching to prevent the horse slipping out forward or backward, and lifted from the ground by a block and tackle carried on an overhead beam or similar support. Used in horses; not a practicable proposition in cattle.
    • Ehmer s. a style of bandage used in dogs and cats that holds the hindleg in flexion with the hip in abduction and internal rotation. Commonly used after reduction of hip luxation.
    • leg s. for the support of a limb in a cattle beast. For a front leg, the rope is looped around the pastern, thrown over an overhead beam, back under the sternum behind the elbow on the same side, then back over the beam. For a hindleg, the rope begins as a loop around the pastern, goes over an overhead support, back inside the thigh on the same side, half-hitched around the tibia, and held by a helper. In both, the leg is lifted off the ground to the required position and the rope tightened to create the sling. 90/90 s. wrapping is applied to maintain the tarsus and stifle in 90-degree flexion; used to prevent contracture of the quadriceps after fracture repair.
    • pelvic limb s. the metatarsus is suspended by tape from a band of gauze and tape around the animal’s abdomen. Used in small animals to prevent weight bearing on the limb, but not primarily for stabilization. Called also Robinson sling.
    • preputial s. a many-tailed bandage around the body with an aperture for the preputial orifice.
    • s. procedure a strip of fascia lata or synthetic material passed around the base of the tail or implanted in perianal tissue have been used in the treatment of fecal incontinence.
    • tail s. a half-hitch is applied to the tail hairs, ensuring that the tissue part is omitted. The rope can be used to support the hindquarters of a horse but not a cattle beast. The technique can be used in cattle as an aid, e.g., to keep the tail out of the way while correcting a dystocia; the rope is tied around the cow’s neck.
    • udder s. a canvas bag with four strategically placed holes for the teats and supported by a harness over the hindquarters anchored to a neck collar to prevent it falling off the back. Not a particularly helpful device because of variation in the size of the vessel to be accommodated.
    • Velpeau s. a gauze wrapping around the thorax and forelimb with the elbow fully flexed and the carpus touching the opposite shoulder. Used in dogs to prevent weight-bearing following surgery, luxation of the shoulder, or fracture of the scapula.
  • slink calves, slinks unborn calves retrieved at the abattoir. Their meat, slink veal, is not authorized for consumption in most countries. Their skins are valuable because they are so fine and clean.
  • slip [slip] see hoof block.
  • slip knot [slip not] one in which the second and subsequent throws can still be snugged down to the surface. The knot is secured with a square knot for the last two throws.
  • slipe unscoured fell-mongered wool.
  • slipped 1. aborted. 2. dislocated or out of place in a more general sense.

    • s. claw flexion of the posterior claw in canaries so the dorsal surface becomes weight-bearing. May be caused by riboflavin deficiency.
    • s. disk see slipped disk.
    • s. epiphysis see epiphysiolysis.
    • s. shoulder see suprascapular paralysis.
    • s. stifle see patellar luxation.
    • s. tendon see perosis.
  • slipper foot see laminitis.
  • slit lamp biomicroscopy see slit lamp.
  • slitter see teat slitter.
  • sliver in wool processing a continuous band of carded and combed wool that has not yet been twisted into yarn.
  • slobbering see drooling.
  • slobbers [slob′ rz] 1. moist dermatitis, or wet dewlap of rabbits; caused by continuous wetting of the dewlap due to poorly placed watering devices. 2. Rhizoctonia leguminicola (slaframine) poisoning in cattle.
  • slope [slōp] in statistical terms the slope of a line depicting the relationship of two variables is the gradient of the line or the regression coefficient of the relationship. A positive slope implies that increasing one variable will increase the other.

    S-63.

    

    Velpeau sling. Prevents weight bearing on the forelimb.

  • slope culture see slant culture.
  • sloth member of the order Pilosa, native to South and Central America, consisiting of the genus Bradypus (three-toed sloths) and genus Choloepus (two-toed sloths). A shaggy-haired, multicolored arboreal animal remarkable for its immobility and slowness of movement when it does move. It spends much time hanging by its paws in a belly-up, face-up position.
  • slough [sluf] 1. a mass of dead tissue in, or cast out from, living tissue. 2. to shed or cast off.

    • anesthetic s. the iatrogenic slough caused by the injection of a necrotizing anesthetic solution subcutaneously in mistake for an intravenous injection. The common sites are over the anterior aspect of the forearm in small animals and over the jugular furrow in large animals.
    • epidermal s. occurs in captive cetaceans when the salinity of the pool water is insufficient.
  • Sloughi a medium-sized, lean, racy dog with a long, flat head, flat ears, a long, thin tail, and a short, fine coat in brindle, sandy, or fawn. Called also Arabian greyhound.
  • Slovakian rough-haired pointer developed from the German wirehaired pointers, Weimaraners and Cesky Fousek, this medium-sized dog has features of all three. The gray-brown to silver, rough coat is distinctive. A breed recognized in the UK and Europe.
  • slow reduced speed of action or reaction.

    • s. death factor see algal poisoning.
    • s.-milking cows 1. cows that require more than 6 minutes to milk right out; the average is 4 minutes. Caused by a too-small sphincter orifice at the tip of the teat.
    • 2.
    • s. virus infections somewhat imprecise term for persistent virus infections characterized by a very prolonged incubation period and a prolonged, chronic progressive clinical course. Originally applied to the lentivirus diseases maedi and visna of sheep in Iceland and also to sheep scrapie, a prion disease.
  • slow-reacting substance of anaphylaxis (SRS or SRS-A) a mixture of leukotrienes secreted by mast cells released in the anaphylactic reaction that induces a slow onset, but prolonged contraction of certain smooth muscles; thought to be important in, for example, bronchoconstriction of asthma.
  • sludge a suspension of solid or semisolid particles in a fluid.

    • activated s. a method of dealing with sewage and abattoir effluent. Consists of an aeration tank in which biologically active, previously sedimented sludge is mixed with incoming effluent and agitated in the presence of an ample supply of air.
  • sludging [sluj′ing] settling out of solid particles from solution.

    • s. of blood intravascular agglutination of erythrocytes into irregular masses, interfering with circulation of blood.

      S-64.

      

      Tissue necrosis and sloughing caused by extravasation of a vesicant in a dog.

  • slug [slug] the garden pest Agriolimax meticulatus; may attract snail poison to a hitherto carefree garden and lead to metaldehyde poisoning in companion animals and may also harbor encysted larvae of Syngamus trachea.
  • slurry [slur′e] solids in suspension. Used as a method of feeding pigs—slurry is pumped through fixed lines and delivered to troughs by hoses equipped with gasoline pump fittings. Used also as a means of disposing of feces and urine from cesspits under animal accommodation or trap tanks attached to milking sheds. Disposal can be onto pasture, but this creates poisoning hazards with respect to heavy metals and transmission of disease such as salmonellosis or Johne’s disease. More commonly local regulations require that it be treated as is human sewerage.
  • sly syndrome [sli] human mucopolysaccharidosis type VII, analogous to β-glucuronidase deficiency mucopolysaccharidosis in experimental dogs.
  • Sm chemical symbol, samarium.
  • small hive beetleAethina tumida feeds on honeybee larvae, pollen, honey, and brood, the excrement contaminates the honey, causing fermentation, and its burrowing damages the wax comb. Native to Africa but has spread to many other countries. A disease notifiable to the OIE (see Table 21).
  • Small Munsterlander pointer a medium-sized (40–50 lb) gun dog with a medium-length, flat coat of brown and white or brown roan. The ears lie flat, similar to spaniels, and the tail is long with feathering. Called Kleiner Munsterlander in Canada.
  • smallpox [smawl′poks] see variola.
  • smartweed see Persicaria, Polygonum.
  • SMCOS-methylcysteine sulfoxide.
  • smear [smēr] a specimen for microscopic study, the material being spread thinly across the slide with a swab or loop, or with the edge of another slide, e.g., blood smear, for differential white cell count, or the evaluation of erythrocyte morphology; fecal smears for the detection of motile stages (trophozoites) of protozoa, such as Giardia, worm eggs, oocysts, or cysts.

    • blood s. see blood film.
    • impression s. one made by pressing the slide against tissue, usually the surface of a neoplasm or the cut surface of a tissue specimen. Called also touch prep.
  • SMEDI group enteroviruses in three subgroups A, B, and C. Found in pigs and cause a shortfall in live pigs, a high incidence of stillbirth and mummification, and a high rate of piglet mortality. SMEDI group of diseases are also causatively linked to porcine parvovirus.
  • slimy skin disease a disease of aquarium fish caused by several different types of protozoan parasites and characterized by copious mucous production on the skin and epithelial cell sloughing.
  • smegma [smeg′m ] the secretion of sebaceous glands, especially the cheesy secretion, consisting principally of desquamated epithelial cells, found chiefly within the prepuce.
  • smell [smel] 1. an odor. 2. the sense that enables an animal to perceive odors. The sense of smell depends on the stimulation of sense organs in the nose by small particles carried in inhaled air. It is important not only for the detection of odors, but also for the enjoyment of food. Flavor is a blend of taste and smell. Taste registers only four qualities: salt, sour, bitter, and sweet; other qualities of flavor depend on smell. The organs of smell are small patches of special (olfactory) cells in the nasal mucosa. One patch is located in each of the two main compartments of the back of the nose. The olfactory cells are connected to the brain by the first cranial (olfactory) nerve.

    • abnormal s. see odor, taint.
    • organ of s. includes the olfactory sense organs, olfactory nerves, and the nerve cells of the olfactory bulb of the brain.
  • smelt small marine finfish in the family Osmeridae.
  • Smith–Baskerville medium a selective medium for the growth of Bordetella bronchiseptica.
  • Smithfield a collie-type herding dog once used for droving cattle around Smithfield Market in London. Distinguished by its bobtail. Not a recognized breed; now found locally in Tasmania. Said to have been a progenitor of the Stumpy-tail Cattle Dog.
  • Smith–Petersen nail [smith′-pa′t r-sen] a flanged nail for fixing the head of the femur in fracture of the femoral neck.
  • smoke [smōk] 1. a coat color of cats that consists of white hairs with black or blue tips. The intensity of the tip color varies on different parts of the body so that the face and back are very strongly colored. 2. a color variety of longhaired cats with orange or copper-colored eyes and a blue or black smoke coat color.

    • s. bombs after ignition may contaminate pasture with phosphorus.
    • s. injury injury caused by exposure to a fire where there is a great deal of smoke, especially one confined in a building. Depending on the source of the smoke and the material being burned, injury is related to physical damage caused to the respiratory tract by heat and compounds in the smoke and noxious substances that are absorbed through the respiratory epithelium and have systemic effects, such as carbon monoxide. Pulmonary edema, decreased mucociliary clearance, and secondary infection are common manifestations.
  • smoking a method of preserving meat or fish (most commonly bacon) that preserves the food’s natural color and flavor. The food is pickled in salt first and then smoked in a smoke house, using special woods for special flavors, for about 3 days.
  • smolt young salmon covered in silvery scales on its way downriver en route to the sea; the fish has undergone physiological adaptations to enable it to survive in salt water.
  • smoltification a metabolic process that enables a fish to adapt from fresh to sea water with a minimum of stress; characteristic of anadromous salmonid fish.
  • smothering death by asphyxiation. Occurs where poultry are carelessly herded into a corner where they cannot escape; when flocks take fright as a result of a novel stimulus and where they are piled four or five birds deep; they will die of asphyxia very quickly. See also crowding.
  • SMSV San Miguel sea lion virus.
  • smudge cell a ruptured leukocyte, seen in a blood smear.
  • smudge patterns the pattern of feces smeared on the buttocks of calves with diarrhea; thought to have diagnostic significance.
  • smut [smut] a group of fungal infections of the seedheads of cereals. Infected grain fed to livestock may be poisonous.

    • barley s.Ustilago hordei thought to cause infertility and stillbirths.
    • wheat s.Tilletia tritici thought to cause glomerulonephritis in pigs.
  • Sn chemical symbol, tin (L. stannum).
  • snail [snāl] gastropod mollusc with a spiral, coiled shell. Some species of snails act as intermediate hosts for flukes and are thus of veterinary importance. Found on land, in fresh and marine waters.

    • s. bait see metaldehyde, methiocarb.
    • mud s. Lymnaeatruncatula.
  • snake [snāk] a limbless carnivorous reptile of the suborder Serpentes; many are venomous. See also milksnake and kingsnake.

    • black s’s. (Pseudechis spp.) highly venomous elapids found in Australia and New Guinea; the venom causes coagulopathy, neurotoxicity, and hemolysis. Depending on the area, it is one of the more common causes of snake bites in companion animals in Australia. Includes the red-bellied black snake (P. porphyriacus) and mulga snake, which is also called King brown snake (P. australis).
    • blind s. see typhlopid.
    • brown s’s. (Pseudonaja spp.) Australian elapids whose venom contains powerful neutoxins and procoagulants; the most common cause of snake bite envenomation in Australia. Includes eastern brown snake (Pseudonaja textilis), or common brown snake, the second most venomous land snake in the world.
    • brown tree s. (Boiga irregularis) a mildly venomous, arboreal, rearfanged colubrid snake, 3–6 ft long. Native to Australia, Indonesia, Papua New Guinea and Melanesian Islands. An invasive species that decimated native fauna population after accidental introduction to Guam after World War II.
    • carpet s. see carpet python.
    • Clarence River s. (Tropidechis carinatus) a banded, olive green snake with a yellow belly and rough scales. A highly venomous Australian elapid, it has a very powerful neurotoxic venom. Called also rough-scaled snake.
    • coral s’s. large group of mostly small elapid snakes, divided in to New World and Old Word species. North American coral snakes are characterized by very colorful bands of red, black and yellow, or white, and have powerful neurotoxins.
    • corn s. (Elaphe guttata) a medium-sized, nonvenomous North American snake; very popular as pets, especially for beginners, because of their docile nature, and they are easy to breed and maintain in captivity.
    • diamond s. see diamond python.
    • garter s.Thamnophis spp. widely distributed small, colubrid snakes with variable color patterns; considered harmless, but there have been reports of allergic reactions to the saliva, which may contain a mild neurotoxin. Widely kept as pets.
    • gopher s. (Pituophis) spp. nonvenomous North American colubrid snakes; in some habitats, sometimes mistaken for rattlesnakes. Sometimes kept as pets.
    • king s. see kingsnake.
    • king brown s. see black snakes (above).
    • mangrove s. (Boiga dendrophila) a large, mildly venomous snake of southeast Asia; black with transverse yellow bands. Called also goldringed cat snake.
    • tiger s. (Notechis spp.) venomous Australian elapids often, but not reliably, distinguished by creamy yellow transverse stripes. Envenomation, characterized by paralysis, coagulopathy, and muscle damage, occurs in animals, particularly dogs and cats, and humans.
    • tree s. a number of colubrid snakes that lead an arboreal existence and practice falling from trees with their body spread out, earning the name of flying snake.
    • s. venom see snakebite.
    • worm s. (Carphophis amoenus) a burrowing, nonvenomous snake with vestigal eyes in the family Typhlopidae; about 10 in. long and looks like a polished, scaly worm. Endemic to Eastern US.
  • snakebite injury caused by the mouthparts of a snake. (1) Cobra-type snakes inject a neurotoxin in their venom causing pupillary dilatation, excitement, convulsions and death due to asphyxia. (2) Adder-type snake venom contains also an agent that causes local swelling and necrosis. If the animal survives the neurotoxin, the part sloughs. (3) Other fractions in some venoms include hemolytic, cardiotoxic, coagulant, and anticoagulant fractions. See also Demansia textilis and tiger snake.
  • snakeroot [snāk′] see Eupatorium rugosum.

    • white s.Eupatorium rugosum.
  • snakeweed see Gutierrezia microcephala.

    • perennial s.Gutierrezia microcephala.
  • snap [snap] a short, sharp sound.

    • s. joint a type of hinge-joint that typically moves abruptly from a central unstable, close-packed position where its collateral ligaments are under tension to one of greater mobility and thence, snapping to an extreme position near the limit of its range as occurs in the equine elbow joint and equine hock.
    • opening s. a short, sharp, high-pitched click occurring in early diastole caused by opening of the mitral cusps, a characteristic sound in mitral stenosis.
  • snapper [snap′ r] Pagrus auratus . Salt water fish
  • snare [snār] an entrapping loop.

    • cable s. see hog¹ holder.
    • obstetrical s. a looped cord for slipping over the head of a fetus to provide traction on the neck. Applied over the nape and through the mouth, not around the neck.
    • pig s. see hog¹ holder.
    • polyp s. an instrument used to grasp and excise a polyp.
    • surgical s. a wire loop for removing polyps and other pedunculated growths by cutting them off at the base.
    • tonsil s. an instrument used to remove tonsils
  • snatch removal of a newborn animal from the dam before it has an opportunity to suck. The objective is to rear it independently and free of colostrum-borne infection or of colostral antibodies.
  • SND standardized normal deviation.
  • sneeze [snēz] 1. an involuntary, sudden, violent, and audible expulsion of air through the mouth and nose. 2. to expel air in such a manner. Sneezing is usually caused by the irritation of sensitive nerve endings in the mucous membrane that lines the nose. Allergies, drafts of cold air, and even bright light can produce sneezing. It is a predominant sign in inclusion body rhinitis in piglets, atrophic rhinitis in older pigs, and feline rhinotracheitis.

    • s. counts number of sneezes per pig per minute. Used as an indicator of the presence or absence of upper respiratory disease in a piggery—greater than 0.33 sneezes per pig per minute accepted as an indication of rhinitis in pigs.
    • reverse s. sporadic, brief periods of noisy, labored inspiration through the nose and nasopharynx, commonly idiopathic in small-breed dogs. Postnasal drip, allergies, and entrapment of the epiglottis have been suggested triggers. Upper respiratory tract infection in cats, foreign bodies, and nasal mites are treatable causes.
  • sneezeweed [snēz′wēd] see Helenium. Includes American or bitter sneezewood (H. amarum), orange sneezeweed (H. hoopesii), smallhead sneezeweed (H. microcephalum).
  • sneezing sudden, reflex, noisy expiration through the nasal cavities.
  • SNF solids-not-fat; a comment on the composition of milk.
  • sniffer dog one trained to detect the presence of specified materials, usually drugs or explosives, by smell. The dogs can be of any breed. Called also detection dogs.
  • snip a white mark on the muzzle extending into one nostril.
  • SNOMED Systematized Nomenclature of Medicine. A coding system for medical terms introduced by the College of American Pathologists in 1975. Later known as SNOMED RT (Related Terms); incorporated in SNOMED-CT.
  • SNOMED CT Systematized Nomenclature of Medicine–Clinical Terms.
  • snood see frontal process (2).
  • SMCA monochloroacetate.
  • Snook hook a surgical instrument with a curved, button tip used to retrieve a horn of the uterus when performing ovariohysterectomy in dogs and cats.
  • snoring an involuntary, deep guttural sound emanating from the pharynx and soft palate on inspiration or expiration; often intermittent depending on posture of the head. May indicate a chronic, obstructive lesion of pharynx.

    • s. disease is an enzootic rhinitis of cattle caused by Helminthosporium spp.
  • snort a forceful expulsion of air through the nostrils as in a sneeze, but a snort is a voluntary act, sneezing is involuntary. Used by horses and cattle as a device to intimidate potential predators.
  • snorter dwarf an achondroplastic dwarf with stertorous respiration due to distortion of nasal passages. See achondroplastic dwarfism.
  • snotsiekte [Af.] see malignant catarrhal fever.
  • snout [snout] the upper lip and the apex of the nose, especially of the pig. Called also rostrum. Has a specialized skin to survive the rigors of rooting, is supported by a separate bone (the os rostri), and also has a few sensory hairs.

    • s. rubbing a vice of pigs characterized by rubbing the snout into the flank until a friction sore develops.
  • SNOVET Systematized Nomenclature of Veterinary Medicine. A controlled vocabulary based on the second edition of SNOMED (Systematized Nomenclature of Medicine), first published by the AVMA in 1985, it replaced the Standard Nomenclature of Veterinary Diseases and Operations (SNVDO).
  • snow [sno] a freezing or frozen mixture consisting of discrete particles or crystals.

    • carbon dioxide s. the solid formed by rapid evaporation of liquid carbon dioxide, giving a temperature of about −110°F (−79°C); used locally in various skin conditions. See also carbon dioxide snow.
    • s. leopard see snow leopard.
    • s. nose see nasal depigmentation.
  • snow-on-the-mountain Euphorbiamarginata.
  • smog [smog] smoke-laden fog, a form of environmental pollution.
  • snowflakes small patches of gray or white hair acquired after birth. Skin color is unchanged. See also achromotrichia, vitiligo.
  • Snowshoe a rare American cat breed distinguished by its color. It is a medium- to large-sized cat with blue eyes, and coat color similar to a sealpoint or bluepoint Siamese, but with a white nose, chin, and ventral midline, and white boots on all feet.
  • snowshoe hare virus one of the California serotype bunyaviruses isolated in Canada from the snowshoe hare. It is a cause of equine viral encephalomyelitis.
  • SNP single nucleotide polymorphism
  • snRNA small nuclear ribonucleic acid (RNA).
  • snRNP small nuclear ribonucleoprotein. See also ribonucleic acid.
  • snuffles [snuf′ lz] 1. an upper respiratory tract disease of rabbits caused by bacterial infection, including Pasteurella multocida, Bordetella bronchiseptica, Staphylococcus, and Pseudomonas spp., characterized by serous and then purulent discharge from the nostrils and eyes that cakes the insides of the forepaws. The rabbit also sneezes and coughs. Pneumonia is a common sequel. 2. chronic rhinitis and sinusitis in cats. Sometimes called chronic snuffles syndrome.

    S-65.

    

    Snout.

    • summer s. is an acute rhinitis of cows characterized by sneezing, purulent nasal discharge, dyspnea. It occurs when pasture is in flower and is thought to be allergic. May be the initial stage of enzootic nasal granuloma.
  • snuffling a bubbling sound from the nasal cavities; an indication of inflammation and the presence of fluid exudate.
  • SNVDO Standard Nomenclature of Veterinary Diseases and Operations.
  • SOAP acronym for subjective data, objective data, assessment, plan, the way the progress notes are organized in problem-oriented medical record keeping.
  • soap [sōp] any compound of one or more fatty acids, or their equivalents, with an alkali. Soap is a detergent and is employed in liniments and enemas and in making pills. It is also a mild aperient, antacid and antiseptic.

    • green s. a potassium soap made by saponification of vegetable oils, excluding coconut oil and palm kernel oil, without the removal of glycerin; it is the chief ingredient of green soap tincture.
    • medicated s. those containing additional ingredients, usually for the treatment of skin disorders, e.g., insecticides, keratolytics, antiseptics, antipruritics.
    • s. poisoning common dishwashing and laundry soaps can be a source of poisoning for dogs and cats, causing gastrointestinal and neurologic signs.
    • soft s. (medicinal) green soap.
    • s. substitute detergents or cleansing creams for cleaning the skin, especially removing greasy films or glandular exudates.
  • soapwort Saponariaofficinalis.
  • Soay sheep small, ancient, primitive, horned sheep from the remote islands of Soay and Hirta, off the northwest coast of Scotland where they were feral. Agile and sure-footed. Brown fleece, lighter color on rump, under the belly, around the eyes, and under the jaw. Both sexes are usually horned. Wool harvested by rooing. Endangered species
  • Soboliphyme baturini a nematode in the family Soboliphymatidae; found in the intestines of foxes, sables, and cats.
  • social pertaining to living in a community.

    • s. dominance hierarchy social order.
    • s. order the ranking in which a group of animals establishes itself with the most dominant one in the number one position and the most retiring one in the last position. The order is maintained unless new animals are introduced.
    • s. organization an aggregation of individual animals into an integrated group based on the interdependence of the animals and their responses to each other.
    • s. rank see social order (above).
  • socialization [so″sh l-ľ-za′sh n] the process of familiarization between animals in a group and, in companion animals, between the animal and humans.

    • s. period the critical age when the young animal is most likely to establish social relationships, forming the basis for its personality, particularly toward humans, and trainability. In puppies, this is from approximately 3–12 weeks of age and approximately 2–7 weeks for kittens.
  • sociosexual behavior pertaining to sexual relationships between animals in groups; behavior such as dominance of one bull over another can have very important effects on the offspring of the groups of cows run with a group of bulls.
  • sock white mark on the feet. In horses, this means from the coronet to halfway up the cannon. In dogs and cats, it is white from the paws up to the carpus or hock.
  • socket [sok′ t] a hollow into which a corresponding part fits.

    • dry s. alveolar osteitis.
    • tooth s. see alveolus.
  • sod-seeding resowing a pasture without ripping it up. Carried out with a special implement that places seed and fertilizer in a sliced furrow with minimum disturbance of existing sward.
  • soda [so′d ] sodium carbonate.

    • baking s. sodium bicarbonate.
    • s. bush see Neobassia proceriflora.
    • s. lime a mixture of 90% calcium hydroxide, 5% sodium hydroxide, 5% silica, and water, used to absorb carbon dioxide from the exhaled air in a semi-closed or closed circuit anesthetic system. See also baralime.
  • sodium (Na) [so′de- m] a chemical element, atomic number 11, atomic weight 22.990. Sodium is the major cation of the extracellular fluid (ECF), constituting 90–95% of all cations in the blood plasma and interstitial fluid; it thus determines the osmolality of the ECF.

    • s. acetate a systemic urinary alkalinizing agent, diuretic, and expectorant.
    • s. acetylsalicylate aspirin.
    • s. acid phosphate, s. biphosphate used as a dietary supplement of phosphorus for ruminants when only phosphorus is required and in small animals as a urinary acidifier.
    • s. aminoarsonate used as a feed additive to chickens and may cause arsenic poisoning if the dose rate is exceeded.
    • s. arsanilate was used as a feed additive in the treatment of swine dysentery and in poultry and causes arsenic poisoning when dose rates are excessive. Not approved in the US.
    • s. arsenite used as a topical acaricide. No longer approved in the US. See inorganic arsenic poisoning.
    • s. ascorbate a form of ascorbic acid; vitamin C.
    • s. azide used in weed control and the prevention of rot in fruit; used in serum samples to prevent bacterial overgrowth.
    • s. benzoate see benzoic acid.
    • s. bicarbonate a white powder found in most households in the form of baking soda; called also bicarbonate of soda. Used as a gastric antacid and as a systemic and urinary alkalinizer. See also milk shake. Used topically in solution to remove mucus and to remove exudates and scabs.
    • s. cacodylate an organic compound yielding trivalent inorganic arsenic on metabolism in the body, similar in effects and toxicity to arsenic trioxide. Formerly used as a systemic treatment for chronic skin disease and capable of causing arsenic poisoning if used to excess.
    • s.-calcium channels see channel.
    • s. carbonate used as an alkalizing agent in pharmaceuticals and in the dietary management of urolithiasis.
    • s. channels see channel.
    • s. chlorate an old-fashioned herbicide that is quite palatable to farm animals and toxic in moderate amounts. Large doses cause abdominal pain, staggering, and purging. Lower doses cause methemoglobinemia and dyspnea.
    • s. chloride salt; a necessary constituent of the body and therefore of the diet; used in parenteral solutions to replenish electrolytes in the body.
    • s. chloride nutritional deficiency not a common occurrence but is seen in grazing animals on sodium deficient pastures, where heavy potash fertilizer has been applied in animals that are milking heavily, growing rapidly, or losing a lot of sweat. Signs include pica, drinking urine, polydipsia, polyuria, and decrease in appetite, milk yield, body weight, and urinary sodium and chloride concentrations.
    • s. chloride poisoning (salt poisoning) can occur via the diet due to accidental inclusion of too much salt, not enough water, or a combination of both. Most common is drinking of natural saline water from bore or deep well. Causes vomiting, gastroenteritis, diarrhea, and dehydration most noticeable in lactating animals. Animals are restless and play with, or look for, fresh water. Water may also contain magnesium, sulfate and carbonate ions. If water intake is restricted, and salt intake is normal, a relative poisoning occurs. Combined with water deprivation, it causes polioencephalomalacia when the water intake returns to normal. In pigs the brain lesion is similar but because of the extensive infiltrations of eosinophils, characteristic of pigs, it is called eosinophilic meningoencephalitis.
    • s. chloroacetate an herbicide with very low toxicity potential.
    • s. citrate an alkalinizing agent; used also as an in vitro anticoagulant in blood stored for transfusion or diagnostic use (primarily coagulation testing), and an oral treatment for renal tubular acidosis.
    • s. cyanide a highly toxic industrial chemical and unlikely to enter the animal food chain unless as a result of a spill of reagents or industrial waste.
    • s. fluoride a white, odorless powder used at one time for the treatment of ascariasis in pigs. Has no use in veterinary medicine comparable to its use as a prophylactic against dental caries in humans. See also fluorosis.
    • s. fluoroacetamide a rodenticide also known as 1081, causes poisoning similar to sodium fluoroacetate (below).
    • s. fluoroacetate occurs naturally in some plants and limited use in agriculture as a rodenticide known as 1080 (to control rodents, coyotes, rabbits, and opossums). The latter is a restricted substance and is only sold on license. Two forms of poisoning occur: (1) myocardial failure resulting in sudden death in herbivora; signs are dyspnea, cardiac irregularity; (2) excitement and convulsions in pigs and dogs. Both poisonings have a high case fatality rate. Plants containing fluoroacetate are Gastrolobium spp., Acacia georgina (gidgee), Dichapetalum spp., Palicourea spp., Amorima spp., Tanaecium spp.
    • s. fluorosilicate is used as an insecticide in bait form for crickets and grasshoppers and as an insecticide dust for poultry. It is as toxic as sodium fluoride.
    • s. glutamate the monosodium salt of l-glutamic acid; used in treat-ment of encephalopathies associated with liver diseases. Also used to enhance the flavor of foods.
    • s. homeostasis maintenance of the body’s sodium status at an appropriate concentration; effected principally by aldosterone increasing tubular resorption of sodium from the glomerular filtrate.
    • s. hyaluronate used in the treatment of degenerative joint disease in horses. See also hyaluronan.
    • s. hydroxide an all-purpose caustic. Its biggest use in veterinary medicine is to clean down fat-laden surfaces in abattoirs prior to disinfection.
    • s. hypochlorite a compound having germicidal, deodorizing, and bleaching properties; used in solution to disinfect utensils, and in diluted form (Dakin’s solution) as a local antibacterial and to irrigate wounds. A common disinfectant for a wide variety of uses in veterinary medicine, including application to cow’s teats in mastitis control programs. Called also bleach.
    • s. iodide used to treat iodine deficiency. At times used parenterally in the treatment of extensive dermatophytosis (ringworm), actinobacillosis and actinomycosis. Overuse causes iodism.
    • s. lactate a compound used in solution to replenish body fluids and electrolytes. See also Hartmann’s solution.
    • s. lauryl sulfate an anionic surface-active agent used in shampoos as a detergent and wetting agent to increase skin penetration of active ingredients.
    • s. metabisulfite used as an antioxidant and as an aid in the making of ensilage. Also used as a preservative on meat, as a source of sulfur dioxide.
    • s. methanearsonate an herbicide—monosodium acid methanearsonate—causes arsenic poisoning.
    • s. molybdate used in salt mixture and as pasture topdressing as a prophylaxis against chronic copper poisoning in ruminants.
    • s. monofluoroacetate see sodium fluoroacetate (above).
    • s. nitrate used in food preservation especially meat pickling and as a fertilizer. Can cause nitrate–nitrite poisoning or nitrite poisoning in ruminants.
    • s. nitrite a vasodilator; used in the treatment of cyanide poisoning. Can cause methemoglobinemia and death from anoxia. In New Zealand, used in baits for the control of brush tail possums and feral pigs.
    • s. oleate used in the past by local injection in horses to cause inflammation and aid healing of chronic injuries such as splints and bucked shins.
    • s. oxalate see soluble oxalate poisoning.
    • s. pentachlorophenate used as a fungicide in wood preservatives. Acute poisoning after heavy dosing causes dyspnea and death due to respiratory failure.
    • s. perborate an oxidizing agent; present in household nonchlorine bleaches with a toxic potential.
    • s. phosphate an osmotic cathartic, used in laxatives and enemas for dogs and foals.
    • s. polyborate used indoors as a powder to control fleas in the environment. Fleas are killed when they ingest it.
    • s.-potassium-ATPase pump see NA⁺, K⁺-ATPase.
    • s.-potassium channels see channel.
    • s./potassium ratio a low ratio, indicating hyponatremia and hyperkalemia, is characteristic of hypoadrenocorticism but can also be seen with renal and gastrointestinal disease.
    • s. propionate used in the prophylaxis and treatment of primary ketosis in cows, and as a fungistat both topically and in preparations for animal medication.
    • s. pump see NA⁺, K⁺-ATPase.
    • s.-restricted diets used in the dietary management of heart disease and hypertension in dogs and cats.
    • s. salicylate an analgesic, antipyretic compound. See salicylate.
    • s. selenite used as treatment for severe nutritional deficiency of selenium. Overdose will cause poisoning by selenium.
    • s. sulfanilate rate of excretion is used as a sensitive test of urinary function. See also sulfanilate.
    • s. sulfate an osmotic cathartic; also used as a diuretic and sometimes applied topically in solution to relieve edema and pain of infected wounds. Called also Glauber’s salts.
    • s. sulfite test 1. precipitates protein out of solution; a dramatic test for protein in urine. 2. a turbidity test on serum for proximate estimation of gamma globulin content and immunological status of newborn calf.
    • s. tetraborate called also borax; used as a weak disinfectant.
    • s. thiosulfate used in the treatment of cyanide poisoning in horses and ruminants; has also been used in the treatment of arsenic poisoning.
    • s. trichloroacetate a nontoxic herbicide.
    • s. versenate see edetate.
  • sodoku [so′do-koo] a relapsing type of infection in humans, dogs, and cats due to Spirillum minus, an organism transmitted by the bite of an infected rat.
  • soft lacking in firmness.

    • s. rolypoly Salsolaaustralis.
    • s. shell disease occurs in turtles and in crustaceans. The cause of the condition is thought to be associated with a mineral and or other nutritional deficiency.
    • s. shelled eggs hen eggs layed without a hard shell, but covered by a thick membrane. May be due to nutritional reasons or occur in birds affected by avian infectious bronchitis and can persist for a long time into the recovery period.
  • Soft-coated wheaten terrier a medium-sized (30–40 lb), compact dog with a soft, silky, wavy, wheaten-colored coat that covers the face and body. The tail is docked. The breed is affected by a familial nephropathy.
  • soft palate the fleshy partition at the back of the mouth that separates the nasopharynx from the oropharynx and that, together with the hard palate, forms the roof of the mouth. Formerly called palatum molle; velum palatinum.

    • cleft s. p. commonly the posterior part is defective but can be part of a defect involving both soft and hard palates. Manifested by difficulties in sucking or nasal regurgitation of milk and food from a young age. Often associated with entrapment of the palate by the aryepiglottic fold. See also cleft lip.
    • s. p. dislocation see dorsal soft palate displacement (below).
    • dorsal s. p. displacement the free edge of the soft palate is displaced from its normal position under the epiglottis to lie over the opening of the larynx causing reduction in airflow. Only in horses.
    • elongated s. p., overlong s. p. a common abnormality in brachycephalic dogs in which it causes inspiratory respiratory distress, gagging, and coughing. The soft palate interferes with the epiglottis and glottis, particularly after it becomes inflamed and edematous. Other anomalies of the respiratory tract commonly are also present. Affected horses appear to choke, then continue to breathe through their mouth with a characteristic rattling sound. The cause and pathogenesis are unclear.
    • s. p. paresis causes a functional pharyngeal paresis; can be part of a syndrome of pharyngeal and laryngeal abnormalities in horses causing reduced athletic performance and detected by dynamic, usually overground, endoscopic examination.
  • softening a change of consistency, with loss of firmness or hardness.
  • Sogdianella moshkovskii a piroplasma now classified in the genus Babesia. Reported to occur in a number of wild and domestic birds.
  • soil the earth, origin of all plant growth and the basis of all animal agriculture. Its characteristics of chemical composition, physical structure, especially porosity and water retaining capacity, its humus content, pH, and salinity exert enormous effects on its productivity.

    • s. analysis an essential activity in densely farmed areas. Measures the soil content of total and available amounts of each of the important soil components.
    • s. contaminated herbage either from dust storms or in loose soil by hoof movement may contribute to dental attrition in sheep, or sand colic in horses.
    • s. eating a form of pica; caused by salt deficiency.
    • s. fumigants are used to prepare fields for planting and may cause poisoning in animals grazing them or eating crops harvested from them. See methyl bromide.
    • s. type includes clay, sand, loam, peat.
  • soilage see zero grazing.
  • soiling see zero grazing.
  • sol [sol] a liquid colloid solution.
  • sol. solution.
  • solanaceous [so″l -na′sh s] pertaining to or emanating from Solanum.
  • solanidine a toxic steroid alkaloid in plants of Solanum.
  • solanine [so′l -nēn] a toxic glycoalkaloid in plants of Solanum. Solanine is cleaved by acid or enzyme hydrolysis to form the aglycone and sugar.

    • s. group the plants in Solanum spp. that contain solanine. Includes, e.g., S. dulcamara, S. nigrum, S. tuberosum, S. lycopersicum, S. melongena, and S. pseudocapsicum.
  • Solanum [so-la′n m] a widespread plant genus of the family Solanaceae that contains a number of valuable crop plants but also some poisonous ones. Poisoning may be due to (1) the presence in the plant of toxic glycoalkaloids that cause diarrhea, (2) alkamines, e.g., nitrosamines, which cause neuromuscular signs of incoordination, and the ‘crazy cow’ syndrome, or (3) calcinogenic glycosides that cause excessive deposition of calcium in tissues. Solanaceous plants that may cause diarrhea syndrome include S. aculeastrum, S. americanum, S. aviculare, S. capsiciforme, S. capsicoides, S. carolinense, S. cinereum, S. dulcamara, S. elaeagnifolium, S. incanum, S. laciniatum, S. lycopersicum (Lycopersicum esculentum, tomato), S. mauritianum, S. melongena, S. nigrum, S. panduriforme, S. pseudocapsicum, S. quadriloculatum, S. rostratum, S. seaforthianum, S. simile, S. sturtianum, S. symonii, S. triflorum, S. tuberosum, S. vescum. Solanaceous plants that cause nervous syndromes include Solanum bonariensis, S. dimidiatum, S. fastigiatum, S. kwebense, S. luederitzii, S. lycopersicum, S. tenuiramosum, S. upingtoniae. Solanaceous plants causing calcinosis include S. glaucophyllum (S. malacoxylon), S. erianthum, S. linneanum (S. hermanii, S. sodomaeum), S. torvum. Solanaceous plants causing miscellaneous syndromes include S. carolinense (inflammation of the mouth and esophagus), S. tuberosum (the common potato), which can cause carbohydrate engorgement. Eating of large quantities over a long period causes dermatitis of the lower limbs in cattle and buffaloes. Greened and sprouted potato tubers contain solanine and cause poisoning if fed without cooking or paring.
  • solar [so′l r] emanating from or pertaining to the sun’s rays.

    • s. burn see sunburn.
    • s. dermatitis see solar dermatitis.
    • nasal s. dermatitis see solar dermatitis, Collie nose.
  • solar-induced squamous cell carcinoma see squamous cell carcinoma.
  • solar plexus [so′l r plek′s s] the network of ganglia and nerves in the center of the abdomen around the origin of the celiac and cranial mesenteric arteries composed principally of the celiac and cranial mesenteric ganglia (celiacomesenteric plexus); it is part of the autonomic nervous system. It is important in the control of the function of the liver, stomach, kidneys, and adrenal glands.
  • solarization exposure to sunlight and the effects produced thereby.
  • solation [sol-a′sh n] the liquefaction of a gel.
  • sole [sōl] the bottom of the foot or hoof.

    • s. abrasion traumatic injury to the sole of the hoof; more common and more serious in soft hooves caused by constant standing in wet footing.
    • s. abscess occurs in all ungulates but most common as a nonspecific disease in horses resulting from nail pricks. Causes pain and lameness, and tetanus in horses, and may extend up behind the wall of the hoof and discharge as a sinus at the coronet.
    • s. corium see solear corium.
    • dropped s. see dropped sole.
    • s. puncture penetration of the sole by a sharp foreign body, e.g., nail.
    • soft s. syndrome soft, crumbly horn in the sole of the hoof, usually all four hooves of the patient are affected, caused usually by failure of wear of the hoof, exacerbated by continued wetness and failure to trim overgrown hooves.
    • s. trauma bruising from excessive walking or walking on rough surfaces occur in horses and cattle. In horses, corns (2) may develop.
    • s. ulcer see pododermatitis circumscripta.
  • solenoglyphous a snake with long posterior facing, mobile fangs that can be rotated to bite, allowing deep penetration and envenomation of the prey. At rest the fangs are folded against the roof of the mouth. Includes the vipers, puff adders, and rattlesnakes.
  • Solenopotes capillatus a sucking louse of cattle in the family Linognathidae. Also known as the ‘little blue sucking louse’.
  • Solenopsis invicta fire ant; their venom, solenopsin A, is cytotoxic and hemolytic. Stings cause an inflammatory skin reaction and sometimes pustular rash in dogs; capable of causing damage to the conjunctiva in calves and recumbent animals.
  • solid [sol′id] 1. not fluid or gaseous; not hollow. 2. a substance or tissue not fluid or gaseous.
  • Solidago North American plant genus in the family Asteraceae; contain an unidentified toxin. In some outbreaks, there is suspicion that the poisoning is caused by a fungus growing on the plant but tests with the plant alone have proved its toxicity. Clinical signs include vomiting, dyspnea, and death in most cases. Identified species include S. chinensis, S. mollis (S. concinna, range goldenrod), S. odora, S. speciosa (goldenrod), S. spectabilis (western goldenrod).
  • solids-not-fat (SNF) the substances in milk other than butterfat and water. They include casein, lactose, vitamins, and minerals that contribute significantly to the nutritive value of milk.
  • soliped single-toed ungulate; an animal with a single uncloven hoof. Includes Equidae only. See also monodactyl.
  • solitary [sol′ľ-tar″e] being the only one or ones.

    • s. cyst unicameral cyst.
    • s. tract nucleus the brainstem nucleus of the solitary tract, the tract carrying afferent parasympathetic nerve fibers.
  • solubility [sol″u-bil′ľ-te] the quality of being soluble.
  • solubles liquid containing soluble and very fine suspended particles in water or solvent. Mostly by-products of fermentation for the manufacture of alcohol. A good dietary protein supplement.
  • solute [sol′ūt] the substance that is dissolved in a liquid (solvent) to form a solution.

    • s. diuresis increase in the volume of urine excreted as a result of an increase in the glomerular filtrate of any osmotically active solute.
  • solution [s -loo′sh n] 1. a liquid preparation of one or more soluble chemical substances usually dissolved in water. 2. the process of dissolving or disrupting.

    • aqueous s. one in which water is used as the solvent.
    • buffer s. one that resists appreciable change in its hydrogen ion concentration (pH) when acid or alkali is added to it.
    • colloid s., colloidal s. a preparation consisting of minute particles of matter suspended in a solvent.
    • hyperbaric s. one having a greater specific gravity than a standard of reference.
    • hypertonic s. one having an osmotic pressure greater than that of a standard of reference.
    • hypobaric s. one having a specific gravity less than that of a standard of reference.
    • hypotonic s. one having an osmotic pressure less than that of a standard of reference.
    • isobaric s. a solution having the same specific gravity as a standard of reference.
    • isotonic s. one having an osmotic pressure the same as that of a standard of reference.
    • molar s. a solution each liter of which contains 1 mole of the dissolved substance; designated 1 M. The concentration of other solutions may be expressed in relation to that of molar solutions as tenth-molar (0.1 M), etc.
    • normal s. a solution each liter of which contains 1 chemical equivalent of the dissolved substance; designated 1 N.
    • ophthalmic s. a sterile solution, free from foreign particles, for instillation into the eye; ‘eye drops’.
    • physiological saline s., physiological salt s., physiological sodium chloride s. an aqueous solution of sodium chloride and other components, having an osmotic pressure identical to that of blood serum.
    • priming s. the fluid used to fill tubing and the reservoir of a cardiac bypass unit before use.
    • saline s. a solution of sodium chloride, or common salt, in purified water.
    • saturated s. a solution in which the solvent has taken up all of the dissolved substance that it can hold in solution.
    • sclerosing s. one containing an irritant substance that will cause obliteration of a space, such as the lumen of a varicose vein or the cavity of a hernial sac.
    • standard s. one containing a fixed amount of solute.
    • supersaturated s. one containing a greater quantity of the solute than the solvent can hold in solution under ordinary conditions.
    • volumetric s. one that contains a specific quantity of solvent per stated unit of volume.
  • solvent 1. capable of dissolving other material. 2. the liquid in which another substance (the solute) is dissolved to form a solution.

    • s. drag transfer of solutes across the intestinal wall by being carried along with the water flow driven by osmotic gradients across cell membranes.
    • s. extraction of oil seeds the oil is extracted by organic solvents, a modern process largely displacing extraction by pressure. The resulting cake or meal may be toxic, e.g., trichloroethylene extracted soybean meal.
    • s. poisoning cases of poisoning may be due to the solvent used in a medication, especially when these are petroleum products, as they are in many insecticide preparations.
  • soma [so′m ] 1. the body as distinguished from the mind. 2. the body tissue as distinguished from the germ cells. 3. the cell body.
  • Somali a medium to large breed of cat similar in appearance to the Abyssinian but with a medium-length haircoat, bushy tail, and ruff around the neck. There are tufts of hair between the toes.
  • Somaphantus lusius a mallophagan louse of guinea fowl.
  • somasthenia [sōm″ s-the′ne-] bodily weakness with poor appetite and poor sleep.
  • somatic [so-mat′ik] 1. pertaining to or characteristic of the body or soma. 2. pertaining to the body wall, not the viscera.

    • s. afferent system the system of sensory neurons scattered around the body and responding to pain, touch, temperature, and other external stimuli.
    • s. cell see somatic cell.
    • s. cell count (SCC) the number of somatic cells per ml of milk. More than 95% of somatic cells in milk are leucocytes (neutrophils, macrophages, and lymphocytes), and the somatic cell count provides a sensitive and specific indicator of udder health and milk quality. Used on an individual cow basis, a count of <100,000 cells/ml is considered to reflect a healthy mammary gland, whereas a count >200,000 cells/ml is suggestive of bacterial infection. Somatic cells in the milk secrete proteolytic enzymes that partially degrade the casein and result in a decrease of the yield of cheese obtained from the milk. They also can change the taste and smell of the milk. There is an inverse relationship between the somatic cell count and milk production. The California mastitis test provides a cow-side measure of somatic cell count. See also bulk tank somatic cell counts.
    • s. cell hybridization fusion in the laboratory of two different populations of somatic cells.
    • s. cell nuclear transfer (SCNT) see cloning.
    • s. mutation theory a theory for antibody diversity, which postulates that only very few immunoglobulin genes are inherited and that the immunoglobulin diversity is created by high rates of mutations occurring within these genes during somatic differentiation.
    • s. myoneural junction see myoneural junction.
    • s. nerves nerves supplying the body wall and limbs.
    • s. pain pain emanating from muscles, skeleton, skin; pain in the parts of the body other than the viscera.
    • s. sensation central perceptions of sensory stimuli from the body wall and limbs include touch, temperature, tickle, itch, pain, conscious proprioception.
  • somation variations in somatic structure that are not hereditary.
  • somat(o)- word element. [Gr.] body.
  • somatochrome [so-mat′o-krōm] any neuron that has a well-marked cell body completely surrounding the nucleus, its colorable protoplasm having a distinct contour; used also adjectively.
  • somatocrinin [so″m -to-kri′nin] see growth hormone releasing hormone.
  • somatogenic [so″m -to-jen′ik] originating in the body.
  • somatology [so″m -tol′ -je] the sum of what is known about the body.
  • somatomammotropin [so″m -to-mam′o-tro″pin] see placental lactogen.
  • somatome 1. an appliance for cutting the body of a fetus. 2. a somite.
  • somatomedin [so″m -to-me′din] any of a group of peptides found in the liver and in plasma that mediate the effect of growth hormone (somatotropin) on cartilage; they are responsible for uptake of sulfate and increased synthesis of collagen and other proteins by cartilage.

    • s. C participates in the limitation of secretion of growth hormone by the pituitary; produced in various tissues, especially liver; called also IGF-1 or insulin-like growth factor.
  • somatometry [so″m -tom′ -tre] measurement of the dimensions of the entire body.
  • somatopagus [so″m -top′-g s] conjoined twins united at the trunks.
  • somatopathy [so″m -top′ -the] a bodily disorder rather than a mental one.
  • somatoplasm [so-mat′o-plaz′ m] the protoplasm of the body cells exclusive of the germ cells.
  • somatopleure [so-mat′o-ploor] the part of the embryo that forms the lateral and ventral walls of the fetus. Consists of somatic mesoderm and ectoderm.
  • somatoschisis [so″m -tos′kľ-sis] 1. splitting of the bodies of the vertebrae. 2. a fissure of the trunk.
  • somatoscopy [so″m -tos′k -pe] examination of the body.
  • somatostatin [so″m -to-stat′in] a cyclic tetradecapeptide hormone and neurotransmitter that inhibits the release of peptide hormones in many tissues. It is released by the hypothalamus to inhibit the release of growth hormone (GH, somatotropin) and thyroid-stimulating hormone (TSH) from the anterior pituitary; it is also released by the delta cells of the islets of Langerhans in the pancreas to inhibit the release of glucagon and insulin and by the similar D cells in the gastrointestinal tract.
  • somatotopic [so″m -to-top′ik] related to particular areas of the body; a correspondence between the form of the body and its representation on an organ such as the brain. The motor and sensory cortices of the brain are arranged somatotopically, with neurons within these regions of the brain laid out in a similar arrangement to the regions of the body that they represent. Some neurological pathways are also arranged somatotopically, with axons carrying information from particular body parts arranged in a similar layout to the body parts themselves, and with this layout maintained throughout the length of those pathways. See also somatotopical projection.
  • somatotopy related to particular areas of the body; a correspondence between the form of the body and its representation on an organ such as the brain. The motor and sensory cortices of the brain are arranged somatotopically, specific regions of the cortex being responsible for different areas of the body. See also somatotopical projection.
  • somatotrope [so-mat′o-trōp] somatotroph.
  • somatotroph [so-mat′o-trōf] any of the cells of the adenohypophysis that secrete growth hormone.
  • somatotropin, somatotrophin [so′m -to-tro″pin] growth hormone. See also pituitary.

    • bovine s. (BST) a protein secreted by the pituitary gland that stimulates body cell growth and milk production. It is available as a synthetically produced product for use in dairy cattle where it can increase milk production, especially in the first 3 months of lactation. Its use is controversial.
  • somatotype [so-mat′o-tīp] a particular type of body build.
  • somatotyping [so-mat′o-tīp″ing] objective classification of animals according to type of body build.
  • somatropin [so-mat′ro-pin] nonproprietary drug name for somatotropin (growth hormone).
  • somite [so′mīt] one of the paired block-like masses of mesoderm beside the neural tube of a vertebrate embryo, formed by transverse subdivision, that develop into the vertebral column, skin, and muscles of the body.
  • somitomere in the developing vertebrate embryo, a segment of paraxial mesoderm.
  • somnifacient [som″nľ-fa′sh nt] agent that causes sleep.
  • somniferous [som-nif′ r- s] producing sleep.
  • somnolence [som′n -l ns] sleepiness; also, unnatural drowsiness. A depressive mental state commonly caused by encephalitis, encephalomalacia, hepatic encephalopathy, hypoxia, and some poisonings, e.g., Filix mas, the male fern.
  • Somogyi effect [so′mo-je] a rebound phenomenon occurring in diabetes mellitus; overtreatment with insulin induces hypoglycemia, which initiates the release of epinephrine (adrenaline), glucagon, cortisol, and growth hormone, which stimulate lipolysis, gluconeogenesis, and glycogenolysis, which, in turn, result in rebound hyperglycemia.
  • Sonchus genus of the plant family Asteraceae; can cause nitrate–nitrite poisoning; called also sow thistles.
  • songbird fever an acute, febrile illness of cats with vomiting and hemorrhagic diarrhea, observed most commonly in the Northeastern US during periods of seasonal bird migration; believed to be caused by Salmonella typhimurium.
  • sonicate [son′ľ-kāt] 1. to expose to sound waves; to disrupt bacteria by exposure to high-frequency sound waves. 2. The products of such disruption.
  • sonication [son″ľ-ka′sh n] exposure to sound waves; disruption of bacteria by exposure to high-frequency sound waves.
  • sonitus tinnitus.
  • sonogram [son′o-gram] a record or image obtained by ultrasonic scanning.
  • sonography [s -nog′r -fe] ultrasonography.
  • sonolucent [son″o-loo′s nt] in ultrasonography, permitting the passage of ultrasound waves without reflecting them back to their source (without giving off echoes). The preferred term is anechoic.
  • sonopuncture [son″o-pungk′ch r] the use of sound vibrations on acupuncture points instead of needles.
  • sonorous [son′ -rs, s-nor′ s] resonant; sounding.
  • Sophora secundiflora [so-fo′r ] North American plant in legume family Fabaceae; toxin is assumed to be an unidentified quinolizidine alkaloid that causes a staggers syndrome in range sheep. When driven affected sheep tremble, stiffen and fall but recover quickly. Most recover if access to the plant is denied. Called also mescal bean, frijolito.
  • sopor [so′por] [L.] deep or profound sleep.
  • soporific [sop″o-rif′ik, so″po-rif′ik] 1. producing deep sleep. 2. an agent that induces sleep.
  • soporous [so′por- s] associated with coma or deep sleep.
  • sorb [sorb] to attract and retain substances by absorption or adsorption.
  • sorbate see sorbic acid.
  • sorbefacient [sor″b -fa′sh nt] 1. promoting absorption. 2. an agent that promotes absorption.
  • sorbent [sor′b nt] an agent that sorbs (absorbs or adsorbs).
  • sorbic acid [sor′bik] a fungistatic preservative used as a food preservative.
  • sorbitol [sor′bľ-tol] a sugar alcohol found in various berries and fruits; in mammals, sorbitol is an intermediate in the conversion of glucose to fructose. It is found in lens deposits in diabetes mellitus. A 50% solution is used as an osmotic diuretic. Sorbitol is used as a sweetener in some dietetic foods; it has the same caloric value as other sugars.

    • s. dehydrogenase (SDH) enzyme that converts sorbitol into fructose; see l-iditol dehydrogenase (ID).
  • sorbose a sugar, a ketohexose, with properties similar to levulose; oral administration causes hemolytic anemia in dogs. Called also l-sorbose.
  • sordes [sor′dēz] foul matter collected on the lips and teeth in low fevers, consisting of food, microorganisms, and epithelial elements.
  • sore [sor] a popular term for any lesion of the skin or mucous membrane.

    • bed s. decubital ulcer.
    • foam s. see scalded skin syndrome.
    • s. foot syndrome erosion of the pads in recently captured large cats. Caused by ceaseless walking and pivoting on a concrete floor.
    • s. head see elaeophoriasis.
    • s. hocks see ulcerative pododermatitis.
    • s. knee see carpitis.
    • s. mouth see contagious ecthyma, vesicular stomatitis.
    • s. muzzle in sheep, see bluetongue.
    • s. nose a crusting, inflammatory skin condition of the nose and muzzle in young, mature gerbils; it can extend to the legs and ventral body with secondary infection. Abrasions from bedding or cages may be an initiating factor, and there are excess secretions from the Harderian gland with accumulation of porphyrin pigment in the skin, causing irritation, self-trauma, and secondary infection. Occurs in conditions of overcrowding and excessive humidity. Called also nasal dermatitis, facial dermatitis, bald nose.
    • pressure s. see decubital ulcer.
    • pus s. see scalded skin syndrome.
    • rub s. a sore found between the toes of Greyhounds and caused by pressure from a joint of a lesser digit on the side of a greater digit.
    • summer s. see swamp cancer.

      S-66.

      

      Sore nose (facial eczema, nasal dermatitis) in a gerbil. Quesenberry, K., Carpenter J. Ferrets, rabbits, and rodents, 3rd ed. W.B. Saunders Company, 2011.

    • sweat s. see scalded skin syndrome.
  • Sorghastrum nutans toxic plant in family Poaceae; causes cyanide poisoning.
  • Sorghum [sōr′gum] grass genus in the plant family Poaceae; can cause cyanide (fresh) and nitrate–nitrite (fresh and dry) poisoning; the cyanide poisoning may be in the peracute, lethal, anoxia form or a chronic form manifested by spinal cord degeneration, ataxia, urinary incontinence and consequential pyelonephritis, or as congenital deformities including arthrogryposis. Includes Sorghum × almum, S. bicolor (S. vulgare, grain sorghum), S. halepense (Johnson grass), S. × drummondii (S. sudanense), S. verticilliflorum (wild sorghum). Includes very valuable fodder crops used extensively as ensilage or green chop, and a grain sorghum used for lot feeding. Fodder sorghum is the more dangerous but both should be considered as potentially poisonous.
  • soring abusive practice of accentuating a horse’s step or gait for competitions. Achieved by irritating an animal’s leg with chemical applications and injections or through mechanical irritants such as straps and chains.
  • sorption [sorp′sh n] the process or state of being sorbed; absorption or adsorption.
  • sorrel 1. a weed and poisonous plant. See Rumex, Oxalis. 2. a horse coat color, light or golden chestnut.
  • S.O.S. [L.] si opus sit (if necessary); a directive that may be used in a prescription.
  • sotalol [so′t -lol] a nonselective β-blocker Class III anti-arrhythmic used in the treatment of cardiac arrhythmias in a variety of species.
  • souffle [soo′f l] a soft, blowing auscultatory sound.

    • cardiac s. any heart murmur of a blowing quality.
    • fetal s. a murmur sometimes heard over the pregnant uterus, supposed to be due to compression of the umbilical cord.
    • funic s., funicular s. a hissing souffle synchronous with fetal heart sounds, probably from the umbilical cord.
    • placental s. a souffle supposed to be produced by the blood current in the placenta; called also placental bruit.
    • uterine s. a sound made by the blood within the arteries of the gravid uterus.
  • sound [sound] 1. percept resulting from stimulation of the ear by mechanical radiant energy, the frequency depending on the species. 2. a slender instrument to be introduced into body passages or cavities, especially for the dilatation of strictures or detection of foreign bodies. 3. a noise, normal or abnormal, emanating from within the body. 4. strong, in good condition and without significant defects, e.g., said of wool that has sufficient tensile strength to resist the rigors of processing; said also of teeth as sound mouth or a horse with no evidence of lameness or other clinical problems.

    • ejection s’s high-pitched clicking sounds heard very shortly after the first heart sound, attributed to sudden distention of a dilated pulmonary artery or aorta or to forceful opening of the pulmonic or aortic cusps.
    • friction s. one produced by rubbing of two surfaces.
    • heart s’s the sounds produced by the functioning of the heart. See heart sounds.
    • Korotkoff’s s’s those heard during auscultatory blood pressure determination.
    • percussion s. any sound obtained by percussion.
    • respiratory s. any sound heard on auscultation over the respiratory tract.
    • succussion s’s splashing sounds heard on succussion over a distended stomach or in hydropneumothorax.
    • to-and-fro s. a peculiar friction sound or murmur heard in pericarditis and pleurisy.
    • urethral s. a long, slender instrument for exploring and dilating the urethra.
    • white s. that produced by a mixture of all frequencies of mechanical vibration perceptible as sound.
  • soundness the expression is usually used with reference to horses. A sound horse has no abnormalities in form or function, that affect, or have the potential to affect, the physical and mental well-being of that animal. These would include, but are not limited to, breeding soundness, soundness of wind, soundness of limbs etc. The opposite of this term is unsound. In Western horsemanship, the term ‘sound’ is typically used to mean that a horse is not lame.

    • s. certificate a certificate setting out the identity of the animal, the client and the veterinarian, the date of the examination, the parts and functions examined, the abnormalities noted, and the conclusion of the examining veterinarian as to the ability of the subject animal to perform the tasks expected of it.
    • s. examination a clinical examination (including clinicopathological, radiological, endoscopic, and oral segments if appropriate), of an animal with a view to providing a certificate of soundness or suitability for sale. A common cause of litigation between horse buyers, or sellers, and the veterinarian performing the examination.
  • sour side putrefaction on the sides of carcasses that have been hung too closely together in the chilling room and that have not cooled quickly enough at the points of contact.
  • source points powerful acupuncture points in the carpal and tarsal areas, used additionally to tonification and sedation points, in the treatment of organ disease or dysfunction.
  • sourcil [soor-sēl′] thickening of subchondral acetabular bone. Used as an indicator of biomechanics in the canine hip joint and in radiographic assessment for hip dysplasia.
  • souring said of ham. See taint.
  • soursob Oxalispes-caprae.
  • sourweed Rumexacetosella.
  • South African mastiff see Boerboel.
  • South African Merino sheep South African version of Merino sheep, originated chiefly from Australian Merino.
  • South African Veterinary Council the regulatory body for the veterinary and para-veterinary professions in South Africa with a statutory duty to determine scientific and ethical standards of professional conduct and education.
  • South American camelids a term, sometimes shorted to its acronym, SAC, that groups the two wild species, vicuña and guanaco, with their two domesticated descendants, alpaca and llama, respectively.
  • South Devon a red, dual-purpose breed of cattle. Called also Devon.
  • South Suffolk a breed of meat Downs-type sheep produced by crossing Southdown and Suffolk sheep.
  • Southdown an English Downs sheep type of short-woolled, meat sheep; polled, gray-brown face and legs. The origin of many crossbred flocks and popular sire of terminal fat-lamb cross. Dystocia is a problem in purebred flocks.
  • Southern blot [suth′ rn] a technique for detecting specific DNA sequences following agar gel electrophoresis of a set of DNA restriction enzyme digestion fragments. The fragments after electrophoresis are transferred to a nitrocellulose or nylon membrane by applying the membrane to the gel; the membrane is probed with a labeled probe that hybridizes to localize one or more of the separated fragments on the membrane. Named for Professor Sir Edward Southern, British molecular biologist.
  • Southern transfer see Southern blot.
  • sow a female pig that has had a litter.

    • dry s. pregnant sow.
    • s. stall a farrowing stall with limited room for movement but maximum protection for the suckers.
    • nonproductive s. days the sow is neither lactating nor gestating. Used as a herd measure of management during the period between weaning of the sow and successful mating.
  • soybean [soi′bēn] the leguminous plant Glycine max (syn. G. soja) used for the production of soya beans. The greatest use of the bean is the extraction of oil for industrial use. The beans are unsuitable for feeding in their raw state unless they are roasted because they contain growthinhibiting factors.

    • s. meal the material left after extraction of soybean oil. It is poisonous if the oil is extracted by elution with trichloroethylene.
    • trichloroethylene-extracted s. meal causes a radiomimetic syndrome of anemia, leukopenia, and submucosal petechiation. Historic syndrome.
  • sp. gr. specific gravity.
  • SPA staphylococcal protein A.
  • space [spās] 1. a delineated area. 2. an actual or potential cavity of the body. 3. the areas of the universe beyond the earth and its atmosphere.

    • dead s. 1. space remaining in tissues as a result of failure of proper closure of surgical or other wounds, permitting accumulation of blood or serum. 2. the portions of the respiratory tract (passages and space in the alveoli) occupied by gas not participating in oxygen–carbon dioxide exchange.
    • Disse s’s small spaces between liver sinusoids and liver cells; conduits for liver lymph. Called also perisinusoidal space.
    • epidural s. the space between the dura mater and the lining of the spinal canal occupied by fat, blood vessels, and nerves.
    • s’s of Fontana fluid spaces separating fibrous trabeculae in the iridal angle meshwork.
    • interalveolar s. the part of the dental arch where there are no teeth.

      S-67.

      

      South American camelids. Face structure of (A) llama and (B) alpaca. Llamas have a longer and less hairy face than do alpacas.

      S-68.

      

      Types of deadspace in an anesthetic ventilation system.

    • intercostal s. the space between adjacent ribs.
    • interpleural s. mediastinum.
    • intervillous s. the space of the human and some other placentae into which the chorionic villi project and through which the maternal blood circulates.
    • intrapleural s. the space between the parietal and visceral pleura, known as the pleural cavity.
    • lumbosacral s. the intervertebral space between the last lumbar and the first sacral vertebrae; suitable site for epidural injection.
    • lymph s’s open spaces filled with lymph in connective or other tissue, especially in the brain and meninges.
    • Meckel’s s. a recess in the dura mater that lodges the trigeminal ganglion.
    • mediastinal s. the space between opposing layers of mediastinal pleura containing the heart, trachea, esophagus, and other structures. Not quite synonymous with mediastinum, which refers to the central partition dividing the thorax as a whole.
    • medullary s. the central cavity and the intervals between the trabeculae of bone that contain the marrow.
    • parasinoidal s’s spaces in the dura mater along the superior sagittal sinus that receive the venous blood.
    • perisinusoidal s. formal name for Disse spaces (above).
    • perivascular s. a lymph space that surrounds the walls of an artery for a short distance as it enters the brain; the walls of the space are bound by arachnoid-like and pia-like membranes so that the intervening channel communicates with the subarachnoid space.
    • plantar s. a fascial space on the sole of the foot of primates, divided by septa into the lateral, middle, and median plantar spaces.
    • pneumatic s. a portion of bone occupied by air-containing cells, especially the spaces constituting the paranasal sinuses.
    • retroperitoneal s. the space between the peritoneum and the dorsal abdominal wall; the space may be used for contrast radiography (pneumoretroperitoneum), and for special surgical access to abdominal organs in the roof of the abdomen where routine laparotomy is contraindicated..
    • retropharyngeal s. the space behind the pharynx, containing areolar tissue, lymph nodes, etc.
    • subarachnoid s. the space between the arachnoid and the pia mater, containing cerebrospinal fluid.
    • subdural s. the slender fluid-filled space between the dura mater and the arachnoid. Called also spatium subdurale.
    • subphrenic s. the space between the diaphragm and subjacent organs of bipeds.
    • Tenon’s s. a lymph space between the sclera and Tenon’s capsule.
  • space-occupying lesions substantial physical lesions, e.g., neoplasm, hemorrhage, granuloma, which occupy space; the effect is more significant if the lesion is within a space confined by bone, e.g., thorax, cranium, bone marrow cavity.
  • Spalding’s sign [spawl′ding] in radiographs, overlapping of fetal cranial bones; a late sign of fetal death.
  • spaniel any of several breeds of bird dogs, used in hunting to ‘flush’ or ‘spring’ the game by following the scent. See American water spaniel, Boykin spaniel, Brittany spaniel, Cavalier King Charles spaniel, Clumber spaniel, Cocker spaniel, Continental toy spaniels, English springer spaniel, Field spaniel, Irish water spaniel, King Charles spaniel, Sussex spaniel, Tibetan spaniel, Welsh springer spaniel.
  • Spaniopsis [span″e-op′sis] a genus of tabanid flies in the family Rhagionidae. They are blood-suckers but do not appear to transmit disease. Also known as snipe flies.
  • Spanish [span′ish] pertaining to or emanating from Spain.

    • S. brown cattle Spanish version of Brown Swiss.
    • S. mastiff a giant (90-150 lb) mastiff-type working dog with a large, powerful head, small eyes, drop ears, and a dense, medium-length coat of various colors.
    • S. Merino sheep original Spanish Merino finewool sheep, ewes mostly polled, rams mostly horned. Progenitors of Australian and South African Merinos and American Ramboulleit
    • S. water dog a medium-sized, multipurpose dog with a distinctive medium-length curly, woolly white, black or chestnut coat that may form cords covering the body and face. The tail is naturally short or docked.
  • Spanish fly [span′ish] contains cantharides. Called also Cantharis vesicatoria (syn. Lytta vesicatoria).
  • SPARCsecreted protein acidic and rich in cysteine. A bone-specific phosphoprotein that selectively binds to collagen. It is the most abundant noncollagenous polypeptide expressed in bone, and has functions in regulating the adhesion of osteoblasts and platelets to their extracellular matrix, as well as early stromal mineralization.
  • sparganosis [spahr″g -no′sis] infection with Spirometra mansoni (syn. S. erinacei), which invades the subcutaneous tissues of pigs causing inflammation and fibrosis. If the lymphatics are involved, there is edematous enlargement of the part. Transmissible to humans who eat infected meat.
  • sparganum [spahr′g -n m] pl. spargana [Gr.] a migrating plerocercoid of a tapeworm of the order Diphyllobothriidea. Usually refers specifically to larvae of Spirometra found in the intermuscular connective tissues or body cavities. Causes sparganosis in humans and pigs.
  • sparrow small gray-brown passerine bird with a universal distribution. Primarily granivorous, but may eat insects; also known as the old-world sparrows or true sparrows. Includes the house sparrow (Passer domesticus);

    • Java s.Lonchura oryzivora, large gray or white finch (up to 6 in. and 30 g) popular as an aviary bird. Also called Java finch, Java rice bird, or Java rice sparrow.
  • sparteine [spahr′tēn] a toxic alkaloid found in Spanish broom and lupins. It causes paralysis of sympathetic ganglia and motor nerve endings.
  • Spartium junceum [spahr′she- m] shrub in the family Fabaceae. Contains the quinolizidine alkaloid cytisine that causes convulsions and fatal respiratory failure. Called also Spanish broom.
  • Spartothamnella juncea Australian plant in the family Verbenaceae; causes nitrate–nitrite poisoning.
  • spasm [spaz′ m] 1. a sudden involuntary contraction of a muscle or group of muscles. 2. a sudden but transitory constriction of a passage, canal, or orifice. Spasms usually occur when the nerves supplying muscles are irritated, and are commonly accompanied by pain. Occasionally a spasm may occur in a blood vessel, and is then called vasospasm. spasms vary from mild twitches to severe seizures and may be the signs of any number of disorders.

    • bronchial s. bronchospasm; spasmodic contraction of the muscular coat of the smaller divisions of the bronchi.
    • inherited congenital s.’s in Jersey calves at birth; lethal within a few weeks; characterized by intermittent, vertical tremor of the head, neck and limbs, making progression and standing impossible; conditioned by a recessive gene.
    • muscle mass s. the basic functional defect in such diseases as Elso heel, inherited periodic spasticity.
    • nodding s. clonic spasm of the sternomastoid muscles, causing a nodding motion of the head.
  • spasmodic [spaz-mod′ik] of the nature of a spasm; occurring in spasms.

    • s. colic see spasmodic colic.
  • spasmolysis [spaz-mol′ľ-sis] the arrest of spasm.
  • spasmolytic [spaz″mo-lit′ik] 1. arresting or checking spasms. 2. an agent that arrests spasms, especially of smooth muscle.
  • spasmophilia abnormal tendency to convulsions; abnormal sensitivity of motor nerves to stimulation with a resultant tendency to spasm.
  • spasmus [spaz′m s] [L.] spasm.

    • s. nutans see nodding spasm.
  • spastic [spas′tik] characterized by spasms, or tightening of the muscles, causing stiff and awkward movements and in some cases a scissors-like gait.

    • s. colon see irritable bowel syndrome.
    • inherited s. paresis of cattle see Elso heel.
  • spasticity [spas-tis′ľ-te] the state of being spastic.

    • inherited neonatal s. signs appear in calves at 2–5 days of age. Unable to stand; if lifted rigidity of all muscles with extension of limbs.
    • inherited periodic s. a defect in cattle that does not appear until they are adults. On rising from a recumbent position the hindlimbs are extended, and the animal is unable to flex them. Spasticity may last for 15 minutes, but the patient will eventually relax and walk normally. Causes inconvenience only. Called also stall-cramp, the stretches.
  • spat name given to juvenile aquatic shellfish that are ready to settlement on solid surfaces—‘spat fall’.
  • Spathiphyllum a genus of plants in the family Araceae; contain calcium oxalate raphide crystals and cause buccal irritation. Called also peace lily.
  • spatial [spa′sh l] pertaining to space.

    • s. clustering in geographical terms the cases in an outbreak of disease are clustered in groups and not spread randomly.
    • s. distribution the distribution of a population within an area.
    • s. pulse length in ultrasound the length of each pulse of sound, related to the wavelength of the sound and the number of waves in each pulse, typically two to three wavelengths per pulse. Affects axial resolution
  • Spatial Epidemiology Team an organization within the USDA Centers for Epidemiology and Animal Health (CEAH) that provides expertise in the use of geospatial methods to analyze and enhance animal health.
  • spatium [spa′she- m] pl. spatia [L.] space.

    • s. interarticulare spaces between the arches of the vertebrae, as in pigs or young animals in which the space between the vertebral arches is large to accommodate the greater length of the vertebral bodies.
    • s. zonularia the many spaces between the fibers of the suspensory ligament of the lens.
  • spatula [spach′ -l] a wide, flat, blunt, usually flexible instrument of little thickness, used for spreading material on a smooth surface or mixing.

    • obstetric s. see Keller spatula, De Bruin spatula.
  • spatulate [spach′ -lāt] 1. having a flat blunt end. In a surgical procedure, opening and spreading apart the ends of a tubular structure in order to increase the diameter of the orifice. 2. to mix or manipulate with a spatula.
  • spavin [spav′in] diseases of the hock joint.

    • bog s. chronic synovitis of the tibiotarsal joint that causes an obvious distention of the capsule of the joint. Called also tarsal hydrarthrosis.
    • bone s. osteoarthritis or osteitis of the distal intertarsal and tarsometatarsal joints of the horse. The lesions are those of a degenerative bone disease terminating in the formation of exostoses and, occasionally, in ankylosis of the joint. Lameness is a constant finding. Called also jack spavin.
    • knee s. an old-fashioned name for chronic carpitis in horses.
    • s. knife see Warmberg spavin knife.
    • occult s. a spavin in which the clinical signs are evident but there is no external bony enlargement. Occasionally termed blind spavin.
    • s. test the horse’s hindlimb is held in a flexed position, with the metatarsus parallel to the ground for several minutes. Increased lameness afterward is considered a positive test for spavin. Called also hock flexion test. Given the reciprocal apparatus of the hindlimb, it is important to recognize that this test will also flex the stifle and hip joints.
  • spawn 1. eggs and sperm of aquatic animals released into the environment. 2.
  • spawners name given to aquatic animals that are reproductively active, see broodfish.
  • spay [spa] to remove the ovaries. See also ovariohysterectomy.

    • s. hook see spay hook.
    • s. spreader a device with a spring loop, like a safety pin, at one end and an outcurving blade at the end of each arm. The blades are inserted into the spay incision and the arms released.
    • vaginal s. ovaries are removed through a colpotomy incision; sometimes performed on mares and extensively managed beef herds in some parts of the world (e.g., Australia).
  • spaying pertaining to spay.

    • s. device see Kimberling–Rupp spaying device.
  • SPCA 1. serum prothrombin conversion accelerator (clotting factor VII). See also clotting factors. 2. Society for the Prevention of Cruelty to Animals; the counterpart in the US and Canada of the RSPCA in British Commonwealth countries.
  • SPD salmon poisoning disease.
  • spear grass see Stipa, Stipagrostis.
  • spearwort a common name for some plants in the genus Ranunculus.
  • special out of the ordinary.

    S-69.

    

    Bog spavin.

  • s. diagnostic strategies includes all techniques that are not provided in the ordinary course of the services available at veterinary clinics and hospital, e.g., Compton metabolic profile, field response trial, retrospective mating analysis.
  • s. senses see special sense.

• specialist [spě′sh l-ist] a veterinarian with advanced postgraduate training and experience in a particular branch of medicine or surgery and has met the requirements of and been accredited by a given specialty organization. See American Veterinary Colleges.

• specialty [spě′sh l-te] a legally recognized field of practice of a specialist.

• species [spe′shēz, spe′sēz] a taxonomic category subordinate to a genus (or subgenus) and superior to a subspecies or variety; composed of individuals similar in certain morphological and physiological characteristics, the important one of which is that they are capable of interbreeding to produce fertile and viable offspring.

  • s. difference the difference between species in their response to therapeutic agents, poisons, and infections due to physical, biochemical, immunological differences.
  • s. specialist a veterinarian who specializes in the diseases and management of an individual animal species.
  • type s. the original species from which the description of the genus is formulated.

• Species360 a centralized database containing information on wild animal species held under human care throughout the world; maintained by member institutions. Known previously as International Species Information System (ISIS), the name was changed to Species360 in 2016.

• species-specific [spe″sēz-sp -sif′ik] characteristic of a particular species; having a characteristic effect on, or interaction with, cells or tissues of members of a particular species; said of an antigen, drug, or infective agent.

• speciesism term used in animal rights for prejudice or attitude of bias toward the interest of members of one’s own species and against those members of other species.

• specific [sp -sif′ik] 1. pertaining to a species. 2. produced by a single kind of microorganism. 3. restricted in application, effect, etc., to a particular structure, function, etc. 4. a remedy specially indicated for a particular disease. 5. in immunology, pertaining to the distinct affinity of antibody for the corresponding antigen.

  • s. acquired immunity see acquired immunity.
  • s. activity enzymes enzyme activity at V_max, measured as μmoles of substrate utilized or product produced per minute, expressed on a specific unit of comparison such as per mg protein or g of tissue weight or ml or L of solution such as plasma.
  • s. drug one that acts at only one type of receptor but may produce several pharmacological effects depending on which organs carry the operant receptor.
  • s. dynamic action (SDA) heat produced by the metabolism of food and unavoidably lost to the animal. In cold environments, it will be contributed to the maintenance of body temperature but in a hot environment it must be dispersed by the normal heat-dissipating mechanisms. Called also heat increment.
  • s. gravity (sp. gr.) the weight of a substance compared with the weight of an equal amount of some other substance taken as a standard. For liquids the usual standard is water. The specific gravity of water is 1; if a sample of urine shows a specific gravity of 1.025, this means that the urine is 1.025 times heavier than water. Specific gravity is measured by means of a hydrometer.
  • s. seasonals clusters of cases occurring at specific seasons.

• specific pathogen free (SPF) a term applied to animals reared for experimentation or to commence new herds or flocks of disease-free animals. Animals usually obtained as for axenic animals but are then placed into a nonsterile environment in which they become infected with a range of microorganisms, many colonizing as normal flora. Certain defined specific pathogenic microorganisms are not present in the environment so that SPF animals can be stated to be free of infection or previous infection with the specified microorganism. See also gnotobiotic animal.

• specificity [spes″ľ-fis′ľ-te] the quality of having a certain action, as of affecting only certain organisms or tissues, or reacting only with certain substances, as antibodies with certain antigens (antigen specificity).

  • drug s. the degree to which the effects of a drug are due to the one pharmacological action.
  • host s. the restricted infectivity of a particular parasite to a certain species or group of hosts.
  • test s. the probability of a test correctly identifying those patients that are not infected or that do not have the specified condition. The fraction of those without disease who will have a negative test result: A fundamental parameter of any diagnostic test. See also sensitivity.
• specimen [spes′ľ-m n] a small sample or part taken to show the nature of the whole, such as a small quantity of urine for urinalysis, or a small fragment of tissue for microscopic study.

  • forensic s. specimen collected in the knowledge that there will probably be litigation relating to the case. Requires complete, accurate identification of the specimen and the patient and client, and that a separate reserve specimen be kept for any further testing required by the court. All containers should be sealed so that they cannot be tampered with, and preferably in the presence of witnesses.

• speckling see ticking.

• SPECT single-photon emission computed tomography. A nuclear medicine imaging procedure in which the gamma camera is rotated around the patient to acquire 3D images with metabolic and functional information.

• spectacle [spek′t -k l] a round lens. Snakes lack movable eyelids, and their corneas are protected by a transparent scale or spectacle that is shed and renewed at each ecdysis. See also subspectacle.

  • s. retention a common problem in snakes; caused by inappropriate humidity and other husbandry issues.

• spectacles [spek′t -k lz] rings inserted through the nasal septum of birds to restrict vision and reduce the occurrence of cannibalism.

• spectinomycin [spek″tľ-no-mi′sin] an aminocyclitol antibiotic derived from Streptomyces spectabili; the hydrochloride is used as a feed additive for swine and chickens.

• spectrin [spek′trin] a cytoskeletal heterodimeric protein important for maintaining the stability, structure, and shape of the cell membrane. It serves additional functions in cell adhesion, intracellular traffic, and the cell cycle.

• spectrometer [spek-trom′ -t r] optical instrument for the measurement of the properties of light over a wide range of wavelengths from gamma rays to the far infrared. Used to identify substances and measure their concentration in solution.

• spectrometry [spek-trom′ -tre] identification of substances or determination of their concentration solution using a spectrometer.

• spectrophotometer [spek″tro-fo-tom′ -t r] an apparatus for determining the ability of a solution to absorb light in or near the visible spectrum by measuring the transmitted light at a specific wavelength.

• spectrophotometry [spek″tro-fo-tom′ -tre] the use of the spectro-photo meter.

• spectroscope [spek′tr -skōp] an instrument for developing and analyzing the spectrum of a substance.

• spectroscopy [spek-tros′k -pe] examination by means of a spect-roscope.

  • nuclear magnetic resonance s. technique depending on measurements of specific radiofrequency emissions produced in a strong magnetic field from molecules containing nuclei with magnetic properties. Used to evaluate metabolic changes within the brain.
• spectrum [spek′tr m] pl. spectra, spectrums [L.] 1. the series of images resulting from the refraction of electromagnetic radiation (e.g., light, x-rays) and their arrangement according to frequency or wavelength. 2. range of activity, as of an antibiotic, or of manifestations, as of a disease.

  • absorption s. one obtained by passing radiation with a continuous spectrum through a selectively absorbing medium.
  • antibacterial s. the range of bacteria susceptible to a particular antimicrobial or class of antimicrobials.
  • broad-s. antimicrobial drug or disinfectant effective against a wide range of microorganisms.
  • narrow-s. antimicrobial drug or disinfectant effective against a restricted range of microorganisms
  • visible s. that portion of the range of wavelengths of electromagnetic vibrations (from 770 to 390 nanometers) that is capable of stimulating specialized sense organs and is perceptible as light.
• speculum [spek′u-l m] an instrument for opening or distending a body orifice or cavity to permit visual inspection.

  • eye s. the epithelial covering over the eye of reptiles; shed with the skin.
  • eyelid s. an instrument used to keep the eyelids apart during surgery.
  • Frick s. a simple metal tube 20 in. × 1.5 in. in diameter with ferruled strengthened ends; used to reach the pharynx of the cow and to pass a stomach tube without fear of damage by the cow’s teeth.
  • Graves s. standard duckbill vaginal speculum. Inserted closed, opened by an exterior screw device that separates two thin blades, semicircular in cross-section. The cervix can be viewed through the external ring of the instrument.
  • McPherson s. a mouth speculum for use in the horse. Called also Haussman gag.
  • mouth s. see mouth speculum, Schoupe speculum (below), Frick speculum (above).
  • ophthalmic s. see eyelid speculum (above).
  • Polanski s. see thoroughbred speculum (below).
  • Schoupe s. used in equine dentistry to keep the mouth open. Consists of a long metal rod with a cross handle. The other end returns on itself and has at its end a coiled spring-like structure that is placed between the molars on the side opposite to where work is to be done.
  • ramp s. see mouth wedge.
  • stomach tube s. see Frick speculum (above), Hauptner mouth gag. For cattle there is also an instrument made out of a wooden rod with a hole through the center. This is placed between the cow’s molars like a bit and held in position with a poll strap. It works adequately for a probang but is much inferior to the Frick speculum for a stomach tube.
  • thoroughbred s. a speculum used for vaginal inspection in mares. There are three slightly curved plates that lie close together when the instrument is closed and can be inserted easily into the vagina. They are opened by a screw mechanism externally causing the plates to separate radially and dilating the vagina. Known also as Polanski speculum or Caslick speculum.
  • vaginal s. see Graves speculum (above) and thoroughbred speculum (above).
• speedy-cutting when the medial aspect of the carpus or metacarpus of the horse is struck by the hoof on the opposite forelimb when moving at a fast speed and when turned sharply.

  • s. boot a boot worn over the wall of the hoof to prevent this injury.

• Speleognathus respiratory tract mites found in commercial poultry and pigeons and many species of wild birds, with one species in bison, but not a significant pathogen.

• spelt a low-grade variant of wheat with similar feed quality but lower yield. Used only as stock feed. Called also Triticum spelta.

• Spencer hemoglobinometer see Spencer hemoglobinometer.

• sperm [sperm] the male germ cell. See also spermatozoon.

  • s. agglutinins anti-sperm antibodies of the IgG class occur as autoantibodies in dogs infected with Brucella canis. Antisperm antibodies may also occur following testicular trauma.
  • s. capacitation acquisition of the capacity to penetrate an ovum, not present at the time of delivery of the spermatozoon, and that requires a period of incubation in the female tract. It involves increased metabolic activity and motility and the removal of a chemical decapacitation factor from the spermatozoon. Capacitation must take place for the acrosome reaction to occur.
  • s. concentration a sperm count as measured in a hemacytometer or spectrophotometer; an indication of the health of the relevant testicles and a guide to the prospective fertility of the ejaculate and the donor.
  • s. live-dead ratio an indicator of the viability of the ejaculate as expressed in a slide count of a specially stained smear of the semen in which the dead and live sperm can be distinguished because of their differential staining.
  • s. morphology the normal anatomical structure of the spermatozoon. Abnormality of the structure of individual spermatozoa is used as a guide to the location and nature of the disease causing reduced reproductive efficiency.
  • s. motility the percentage of spermatozoa moving actively forward. Assessed under the microscope (400 × magnification) or by computerized imaging. See also wave motion; used to predict the probable fertility of the ejaculate.
  • s. motility index half the sum of the sample’s sperm percentage motility + sperm progressive motility.

    S-70a.

    

    Primary spermatozoal abnormalities involving the head include double head (bicephaly) (1), small head (microcephaly) (2), large head (macrocephaly) (3), pear-shaped head (pyriform) (4), elongated head (5), and round head (6).

    S-70b.

    

    Primary spermatozoal abnormalities involving the midpiece and tail include swollen midpiece (1), coiled midpiece and coiled tail (2), bent midpiece (3), double midpiece (4), and abaxial midpiece (5).

  • s. penetration assay see ovum penetration assay.
  • s. stone hard bodies composed of inspissated masses of spermatozoa found in dilated remnants of epididymal ducts and produced by chronic epididymitis.
  • s. transport within both male and female reproductive tracts some movement forward results from the movements of the spermatozoa but most progress is the result of peristaltic movements by the tubular organs in which the spermatozoa find themselves at the time.

• spermastasis accumulation of spermatozoa in the part of the male genital tract resulting from a blockage at the level of ampullae, ductus deferens or tail, or epididymis.

• spermatheca accessory organ opening into the common oviduct in female insects; stores spermatozoa delivered by the male during copulation; the sperm may remain viable for the life of the female.

• spermatic [sp r-mat′ik] pertaining to the spermatozoa or to semen.

  • s. cord the structure extending from the deep inguinal ring to the testis, comprising the ductus deferens, testicular artery, and vein including the pampiniform plexus, lymphatic ducts, autonomic nerves as a testicular plexus, smooth muscle tissue around the vessels, called also internal cremaster muscle, and the visceral layer of the vaginal tunic. Clinicians are likely to include the external cremaster muscle, and the parietal layer of the vaginal tunic as parts of the cord, although, strictly, these structures simply surround the cord. Called also funiculus spermaticus.
  • s. cord torsion torsion of the cord to the point where circulation in the blood vessels of the cord ceases; rare but occasional occurrence in dogs, stallions, and other species, particularly where the testicle is retained and enlarged by tumor. Causes acute abdominal pain and death due to shock. Incorrectly called testicular torsion.

• spermaticide [sper′m -to-sīd″] spermicide.

• spermatid [sper′m -tid] a cell produced by meiotic division of a secondary spermatocyte; it develops into the spermatozoon.

• spermatitis [sper″m -ti′tis] inflammation of a vas deferens; deferentitis.

• spermat(o)- word element. [Gr.] seed; specifically used to refer to the male germinal element. See also sperm(o)-.

• spermatoblast [sper′m -to-blast″] spermatid.

• spermatocele [sper′m -to-sēl″] a cystic distention of the epididymis or rete testis, containing spermatozoa.

• spermatocelectomy [sp r-mat″o-s-lek′t -me] excision of a spermatocele.

• spermatocidal [sper″m -to-si′d l] destructive to spermatozoa.

• spermatocyst [sper′m -to-sist″] 1. a vesicular gland (seminal vesicle). 2. spermatocele.

• spermatocystectomy [sper′m -to-sis-tek′t -me] excision of a vesicular gland (seminal vesicle).

• spermatocystitis [sper′m -to-sis-ti′tis] inflammation of a seminal vesicle.

• spermatocystotomy [sper′m -to-sis-tot′ -me] incision of a seminal vesicle, for the purpose of drainage.

• spermatocyte [sp r-mat′o-sīt] the progenitor cell of a spermatid. a cell (primary spermatocyte) produced by mitosis from type B spermatogonia. Subsequent meiotic division of the primary spermatocyte yields two haploid secondary spermatocytes that give rise to spermatids following the second meiosis.

  • primary s. daughter cell of a spermatogonium. Following the first meiotic division it gives rise to the secondary spermatocyte.
  • secondary s. a cell produced by meiotic division of the primary spermatocyte, and that gives rise to the spermatid.

• spermatocytogenesis [sper″m -to-si″to-jen′ -sis] the first stage of formation of spermatozoa, in which the spermatogonia develop into spermatocytes and then into spermatids.

• spermatogenesis [sper″m -to-si″to-jen′ -sis] the development of mature spermatozoa from spermatogonia; it includes spermatocytogenesis and spermiogenesis.

• spermatogenic [sper″m -to-jen′ik] giving rise to spermatozoa.

  • s. cycle duration of the cycle that separates consecutive cell divisions of spermatogonia (pig is 8 days, sheep 10, cattle 14) to produce spermatocytes.
  • s. wave spermatogenesis occurs in sequential waves along the length of the seminiferous tubules so that spermatozoa are produced in waves; the phenomenon that ensures that spermatozoa are produced continuously, except for seasonal pauses when spermatogenesis is initiated and terminated each year.

• spermatogonium [sper″m -to-go′ne- m] pl. spermatogonia [Gr.] an undifferentiated male germ cell, originating in a seminal tubule and dividing into a new generation of spermatogonia or into two spermatocytes.

• spermatoid [sper′m -toid] resembling semen.

• spermatolysin [sper″m -tol′ľ-sin] a lysin destructive to spermatozoa.

• spermatolysis [sper′m -tol′ľ-sis] dissolution of spermatozoa.

• spermatopathia abnormality of the semen.

• spermatorrhea involuntary escape of semen, without orgasm.

• spermatoschesis suppression of the semen.

• spermatoxin [sper′m -tok″sin] a toxin that destroys spermatozoa.

• spermatozoa [sper″m -to-zo′] see spermatozoon.

• spermatozoal [sper″m -to-zo′ l] pertaining to spermatozoa.

  • s. motility a guide to viability and potency of a semen sample; in ruminants, a highly motile sample shows wave movement under low power of the microscope and individual sperm movement under high power. In species with high volume and low concentration, only individual motility is recorded.

• spermatozoicide an agent that destroys spermatozoa; spermicide.

• spermatozoon [sper″m -to-zo′on] pl. spermatozoa a mature male germ cell, the specific output of the testes, which impregnates the ovum in sexual reproduction. The mature sperm cell is microscopic in size. Shape varies by species; in many it looks like a translucent tadpole, and has a flat, elliptical head containing a spherical center section, and a long tail by which it propels itself with a vigorous lashing movement.

  S-71.

  

  A normal spermatozoon.

• spermaturia [sper″m -tu′re-] seminuria.

• spermectomy excision of part of the spermatic cord.

• spermicide [sper′mľ-sīd] an agent destructive to spermatozoa.

• spermidine [sper′mľ-din] a polyamine first found in human semen but now known to occur in almost all tissues, in association with nucleic acids.

• spermiduct [sper′mľ-dukt″] a synonym for the ejaculatory duct and vas deferens together.

• spermine [sper′min] a biogenic polyamine formed from spermidine that was first found in human semen, but now is known to occur in almost all tissues. It plays important roles in cellular metabolism in eukaryotic cells and some bacteria.

• spermiogenesis [sper″me-o-jen′ -sis] the second stage in the formation of spermatozoa, in which the spermatids transform into spermatozoa.

• spermioteleosis progressive development of the spermatogonium through various stages to the mature spermatozoon.

• sperm(o)- word element. [Gr.] seed; specifically used to refer to the male germinal element. See also spermat(o)-.

• spermolith [sper′mo-lith] a calculus in the vas deferens, or elsewhere in male reproductive tract such as seminiferous tubule, ampulla or vesicular gland.

• spermophlebectasia varicose state of the spermatic veins.

• spermotoxin [sper′mo-tok″sin] a toxin lethal to spermatozoa; especially an antibody produced by injection of an animal with spermatozoa.

• spewing sicknessHelenium spp., Hymenoxys spp. poisonings.

• spey spay.

• SPF specific pathogen free.

• Sphacelia typhina see Neotyphodium coenophialum.

• Sphaeridiotrema a genus of small, globular digenetic trematodes in the family Psilostomatidae.

  • S. globulosus found in the intestine of wild and domestic ducks and in swans and causes severe enteritis. It has caused severe mortalities in swans.
  • S. spinoacetabulum inhibits the ceca and causes severe typhlitis.

• Sphaerophorus necrophorus see Fusobacterium necrophorum.

• Sphaerothecum destruens previously called the Rosette agent. Causes systemic disease in salmonid fish and some freshwater species, characterized by swollen kidneys and spleen, and lymphocytosis. A member of the eukaryotic class Mesomycetozoea.

• sphenion [sfe′ne-on] the point at the sphenoid angle of the parietal bone.

• sphen(o)- word element. [Gr.] wedge-shaped, sphenoid bone.

• sphenoid [sfe′noid] 1. wedge-shaped. 2. an irregular wedge-shaped bone at the base of the skull. See also Table 9.

  • s. bone fracture fracture of the basisphenoid bone occurs when the horse rears over backward striking its poll. Causes signs of vestibular disease and facial nerve injury including head tilt, facial paralysis, epistaxis, and hemorrhage into guttural pouch. Usually associated with rupture of longus capitus muscle.

• sphenoidal [sfe-noi′d l] pertaining to the sphenoid bone.

• sphenoiditis [sfe″noi-di′tis] inflammation of the sphenoidal sinus.

• sphenoidotomy [sfe″noi-dot′ -me] incision of a sphenoid sinus.

• sphenomaxillary [sfe″no-mak′sľ-lar″e] pertaining to the sphenoid bone and the maxilla.

• sphenopalatine [sfe″no-pal′ -tīn] pertaining to the sphenoid and palatine bones.

  • s. sinus in horses the sphenoid sinus extends into the palatine bone.

• Sphenosciadium capitellatum North American alpine plant in the family Apiaceae; contains an unidentified toxin that causes pulmonary edema and photosensitization. Called also woolyhead parsnip, whiteheads.

• sphenotresia perforation of the base of the fetal skull in craniotomy.

• sphenotribe an instrument used for crushing the base of the fetal skull.

• sphere [sfēr] a ball or globe.

  • attraction s. centrosome.
  • segmentation s. 1. the morula. 2. a blastomere.

• spher(o)- word element. [Gr.] round, a sphere.

• spherocyte [sfēr′o-sīt] a spherical, darkly staining erythrocyte; readily detected in dogs because the typical central pallor is absent; characteristically found in some types of acquired hemolytic anemia, particularly immune-mediated.

• spherocytosis [sfēr″o-si-to′sis] the presence of spherocytes in the blood.

  • hereditary s. an inherited autosomal, incompletely dominant trait in Japanese black cattle; causes hemolytic anemia due to mutations in the AE1 (anion exchanger 1, band 3) gene.
• spheroid [sfēr′oid] a sphere-like body.

  • axonal s’s these appear in axons in the early stages of development of progressive axonopathy; the spheroids are eosinophilic, round or oval axonal swellings containing degenerate organelles. See also torpedoes.

• spheroidal [sfēr-oi′d l] resembling a sphere.

• spheroma a globular tumor.

• spherophakia [sfēr″o-fa′ke- ] a spherical deformation of the lens.

• spheroplast [sfēr′o-plast] gram-negative bacterial cell deprived of its cell wall, but retaining an intact plasma membrane. See also protoplast.

• spherules [sfēr′ūl] highly refractile cystic structure containing multiple endospores characteristic of the fungus Coccidioides immitis when growing in animal tissues. Also called sporangia.

• sphincter [sfingk′t r] a circular muscle that constricts a passage or closes a natural orifice. When relaxed, a sphincter allows materials to pass through the opening. When contracted, it closes the opening. The principal abnormalities relate to function. Failure to open may be because of spasm or achalasia, due usually to failure of parasympathetic nerve supply. Failure to close is usually due to absence of sympathetic nerve supply. The important sphincters are the anal, ileal, pharyngoesophageal, pupillary, pyloric, reticulo-omasal, teat, urethral, vaginal, and vesical.

  • cardiac s. the functional sphincter at the gastric end of the esophagus.
  • s. control is by the autonomic nervous system.
  • esophageal s. see cardiac sphincter.
  • s. of Oddi bile duct sphincter.
  • pupillary s. a ring of smooth muscle around the pupillary border of the iris.

• sphincterectomy [sfingk″t r-ek′t -me] excision of a sphincter.

• sphincterismus [sfingk″t r-iz′m s] spasm of a sphincter.

• sphincteritis [sfingk″t r-i′tis] inflammation of a sphincter, particularly the sphincter of Oddi.

• sphincterolysis [sfingk″t r-ol′ľ-sis] surgical separation of the iris from the cornea in anterior synechia.

• sphincteroplasty [sfingk′t r-o-plas″te] plastic reconstruction of a sphincter.

• sphincterotomy incision of a sphincter.

• sphingolipid [sfing″go-lip′id] one of the two dominant ‘families’ of phospholipids found in membranes; a type of phospholipid containing sphingosine (e.g., ceramides, sphingomyelins, gangliosides, and cerebrosides), occurring in high concentrations in the brain and other nerve tissue.

• sphingolipidosis [sfing″go-lip″ľ-do′sis] pl. sphingolipidoses [Gr.] a general designation applied to diseases characterized by abnormal storage of sphingolipids, such as gangliosidosis, Gaucher’s disease, glucocerebroside, globoid cell leukodystrophy, and sphingomyelinosis.

• sphingolipodystrophy [sfing″go-lip″o-dis′tr -fe] any of a group of disorders of sphingolipid metabolism. See also sphingolipidosis.

• sphingomyelin [sfing″go-mi′ -lin] a group of phospholipids consisting of sphingosine, a fatty acid, and a phosphocholine or phosphoethanolamine head group. A major component of cell membranes, especially in the myelin sheath; found predominantly in the outer half of the lipid bilayer.

  • s. lipidosis see sphingomyelinosis.

• sphingomyelinosis [sfing″go-mi″ -lin-o′sis] an inherited deficiency of sphingomyelinase in cats, dogs, calves, and mice that results in abnormal accumulation of sphingomyelin in nervous tissue, liver, and spleen. Clinical signs include retarded growth and neurological abnormalities from an early age. The disease in cats and miniature poodles closely resembles Niemann–Pick disease of humans. Called also sphingomyelin lipidosis.

• sphingosine [sfing′go-sēn] a basic amino alcohol with a long hydrocarbon chain, present in sphingomyelin and other sphingolipids.

• Sphinx a cat breed derived from a mutant with a generalized absence of a fur coat, but with fine down hairs present; transmitted as a recessive trait. Now being promoted as a distinct breed. See also alopecia universalis. Called also Canadian hairless cat.

• sphygmic [sfig′mik] pertaining to the pulse.

  • s. period the second phase of ventricular systole, between the opening and closing of the semilunar valves, while the blood is propelled into the aorta and pulmonary artery.

• sphygm(o)- word element. [Gr.] relationship to the pulse.

• sphygmobolometer an instrument for recording the force of the pulse wave, and so, indirectly, the strength of systole.

• sphygmochronograph [sfig″mo-kro′no-graf] a modified sphymograph that graphically displays the pulse rate per unit time.

• sphygmodynamometer [sfig″mo-di″n -mom′-t r] an instrument for measuring the force of the pulse.

• sphygmogram [sfig′mo-gram] the record or tracing made by a sphygmograph; called also pulse tracing.

  S-72.

  

  A Sphinx cat, demonstrating the all most total alopecia typical of this breed. Hnilica, K. Small Animal Dermatology: A Color Atlas and Therapeutic Guide, 4th ed. Saunders, 2016.

• sphygmograph [sfig′mo-graf] an apparatus for recording the variations in blood pressure and pulse rate.

• sphygmoid [sfig′moid] resembling the pulse.

• sphygmomanometer [sfig″mo-m -nom′-t r] an instrument for measuring arterial blood pressure.

  • Doppler-shift s. an instrument that replaces auscultation of the artery for the appearance and disappearance of Korotkoff sounds by an ultrasound flowmeter.

• sphygmometer [sfig-mom′ -t r] an instrument for measuring the force and frequency of the pulse. Sphygmomanometer is the device used for measuring blood pressure

• sphygmoscope [sfig′mo-skōp] a device for rendering the pulse wave visible.

• sphygmotonometer [sfig″mo-to-nom′ -t r] an instrument for measuring the elasticity of arterial walls.

• sphyrectomy excision of the malleus, or hammer, of the ear.

• spica bandage [spi′k ] figure-of-eight bandage that is applied around a joint or trunk.

• spicule [spik′ūl] 1. literally. a sharp, needle-like body or spike. 2. Part of the male genital apparatus in nematodes; they engage the female genital orifice during copulation.

• Spiculocaulus a genus of nematodes in the family Protostrongylidae and found in the lungs of small ruminants. Includes S. austriacus (goats and ibex), S. kwongi (sheep and goats), S. leukarti (sheep and ibex), and S. orloffi (sheep, goats and ibex).

• Spiculopteragia a genus of worms in the family Trichostrongylidae, found in the abomasum of cervids and ruminants. The taxonomy of this genus is complicated by the presence of morphologically different male morphs in most species and consequently, taxonomic changes are frequent.

  • S. boehmi found in moufflon and deer and occasionally in cattle.
  • S. houdemani with S. andreviae as its minor morph. Primarily parasites of deer but may also occur in cattle.
  • S. peruviana found in llama, alpaca, and vicuña.
  • S. spiculoptera found primarily in deer. S. mathevossiani is considered by some authors to be a minor morph of this species, although other authors attribute S. mathevossiani as a minor morph of S. boehmi.
  • S. asymmetrica minor morph S. quadrispiculata; primarily parasitic in deer but may occur in cattle
• spider an arthropod of the class Arachnida.

  • black widow s. see Latrodectus mactans.
  • brown recluse s. a venomous spider, Loxoceles reclusa, whose bite causes severe poisoning in humans and hard-to-heal dermonecrotic wounds in dogs and cattle.
  • cobweb s’s. members of the dipneumonomorph spiders in the family Theridiidae. Includes the red-back or black widow spider.
  • funnel-web s. a very venomous spider that lives in a funnel-shaped web built into a horizontal crack or existing burrow. A bite causes intense pain at the site and then generally, sweating, dehydration and paralysis, and is often fatal. Called also Sydney funnel-web spider, Atrax robustus.
  • hourglass s’s. those with the red hourglass-shaped marking on the ventral body characteristic of some members of the genus Latrodectus, including the black widow and red-backed spiders.
  • redback s. see Latrodectus.
  • trapdoor s. (Atrax formidabilis); a very venomous spider that lives in a funnel-shaped web built into a horizontal crack or existing burrow. A bite causes intense pain at the site and then generally, sweating, dehydration, and paralysis, and may be fatal.
  • s. grass Brachyachneconvergens.
  • s. lamb syndrome inherited arachnomelia.

• spider cell [spi′d r] cells in rhabdomyosarcoma that have extensively vacuolated cytoplasm.

• spike [spīk] 1. a sharp upward deflection in a curve or tracing, as on the encephalogram. 2. prepare samples with a known amount of substance for testing laboratory proficiency.

• spikes see peplomer.

• Spilopsyllus cuniculi a flea in the order Siphonaptera. A parasite of rabbits and hares and occasionally their predators; transmits myxomatosis. Also called the European rabbit flea. Reproduction in the flea is initiated by reproductive hormones in pregnant rabbits upon which the fleas feed. A cause of severe irritation on the pinnae of domestic cats.

• spina [spi′n ] pl. spinae [L.] spine; a slender process such as occurs on many bones.

  • s. bifida a developmental anomaly characterized by defective closure of the two halves of the vertebral arch through which the spinal cord and meninges may or may not protrude.
  • s. bifida cystica spina bifida in which there is protrusion through the defect of a cystic swelling involving the meninges (meningocele), spinal cord (myelocele), or both (meningomyelocele).
  • s. bifida occulta spina bifida in which there is a defect of the bony spinal canal without protrusion of the cord or meninges.
  • s. bifida ventralis a defect of closure on the ventral surface of the bony spinal canal, often associated with defective development of the abdominal and thoracic viscera.
• spinach Spinacia oleracea.

  • Cape s. see Emex australis.
  • New Zealand s. Tetragonia tetragonioides.
  • red s. Trianthematriquetra.

• Spinacia oleracea plant in the family Chenopodiaceae; can cause soluble oxalate poisoning comprising nephrosis, urolithiasis. Called also spinach.

• spinal [spi′n l] pertaining to a spine or to the vertebral column and in many instances to the spinal cord.

  • s. abscess infection may be introduced hematologically from navel infection to a vertebral body or up the vertebral canal from an infected docking wound. Clinically there is a development of paresis over a few days then paraplegia when the abscess is in the lumbar region or quadriplegia when it is located in the cervical area.
  • s. accessory nerve see accessory nerve, Table 13.
  • congenital s. stenosis stenosis of the vertebral canal present at birth; recorded in calves.
  • s. fibrocartilaginous emboli see fibrocartilaginous embolic myelopathy. focal symmetrical s. poliomalacia see focal symmetrical spinal poliomalacia.
  • s. fusion surgical creation of ankylosis of contiguous vertebrae.
  • s. meninges see meninges.
  • s. meningitis see steroid-responsive meningitis-arteritis.
  • s. muscular atrophy see hereditary spinal muscular atrophy, hereditary neuronal abiotrophy of Swedish Lapland dogs.
  • s. myelitis see myelitis.
  • s. myelopathy see myelopathy.
  • s. nerve any of the paired nerves arising from the spinal cord and passing out between the vertebrae.
  • s. puncture introduction of a hollow needle into the subarachnoid space of the spinal canal, usually for the purpose of collecting a sample of cerebrospinal fluid, to introduce radiopaque material for myelography, or the injection of an anesthetic. See lumbar puncture.
  • s. reflex any reflex action mediated through synapses in the spinal cord.
  • s. stenosis see spinal cord compression.
  • s. tap see spinal puncture (above).
  • s. trauma temporary or permanent dislocation of one or more spinal vertebrae; or fracture; causes immediate flaccid paralysis caudal to injury due to spinal shock, followed by residual signs due to damage to spinal cord tissue.
  • s. walking see reflex walking.
• spinal cord that part of the central nervous system lodged in the spinal canal, extending from the foramen magnum to a point in the lumbar or sacral vertebrae, depending on the species.

  • s. c. abscess see spinal abscess.
  • s. c. atrophy diminution in mass of the entire cord, is usually the hallmark of undernutrition or old age, or both.
  • s. c. compression compression of the spinal cord. Compression may occur gradually due to space-occupying lesions of the vertebral canal, such as abscess, callus of a fracture, or a tumor, or acutely due to fracture dislocation or thrombosis. In general, clinical signs depend on the level of the spinal cord involved and the speed and the degree of compression and may include paresis, paralysis, urinary incontinence, loss of sensation, Horner’s syndrome, and in acute lesions, spinal shock.
  • s. c. degeneration see myelomalacia.
  • s. c. hemorrhage see hematomyelia.
  • s. c. hypoplasia usually segmental, especially in the lumbar area.
  • s. c. local ischemia caused by embolus of a spinal artery; has the same effect as traumatic injury (see below).
  • s. c. tracts more or less distinct bundles of fibers within the white matter of the spinal cord. There are three funiculi on each side of the cord—dorsal, lateral, and ventral; subdivisions within the funiculi include 11 major tracts—gracile and cuneate fasciculi, lateral and ventral corticospinal tracts, rubrospinal tract, dorsal and ventral spinocerebellar tracts, lateral and ventral spinothalamic tracts, elementary apparatus fibers, ventral corticospinal tract, vestibulospinal tract.
  • s. c. traumatic injury fracture or dislocation of one or more vertebrae; causes a syndrome of acute flaccid paralysis in the area supplied with nerves from the injured segment and spastic paralysis in the parts supplied by the cord segments caudal to the injury. In the early stages following injury spinal shock may also occur.

• spinate [spi′nāt] thorn-shaped; having thorns.

• spindle [spin′d l] 1. mitotic spindle; the fusiform figure occurring during metaphase of cell division, composed of microtubules radiating from the centrioles and connecting to the chromosomes at their centromeres. 2. muscle spindle; a mechanoreceptor found within a skeletal muscle; the muscle spindles are arranged in parallel with muscle fibers. They contain 3–10 small, striated muscle fibers (intrafusal fibers) contained within a capsule and supplied with specialized motor and sensory nerves. They respond to passive stretch of the muscle but cease to discharge if the muscle contracts isotonically, thus signaling muscle length. The muscle spindle is the receptor responsible for the stretch or myotatic reflex.

  • s. wood, s. tree Euonymus europaeus.
• spindle-cell tumors tumors that arise from spindle-shaped cells of the dermis and subcutis.

  • cutaneous s.-c. tumors include fibroma, fibrous histiocytoma, schwannoma, hemangiopericytoma, and their corresponding malignant counterparts, equine sarcoid, collagen nevi, papilloma-virus-induced fibropapillomas, and spindle-cell dermal melanomas. See also soft-tissue sarcoma.

• spindle-shaped shaped like a round stick tapered at both ends.

• spindly leg syndrome a developmental disease seen in frogs and toads; after metamorphosis, the forelimbs are underdeveloped. May be due to nutritional deficiencies.

• spine, spina [spīn] 1. a thornlike process or projection. 2. the backbone, or vertebral column. See also spinal.

  • cervical s. (2) the part of the spine made up of cervical vertebrae.
  • cuneal s. (1) the axial ridge of the upper surface of the frog in the hoof of the horse that projects into the digital cushion.
  • iliac s. (2) small salients along the dorsal and ventral borders of the ilium, divided into cranial and caudal, dorsal and ventral, in cats and dogs, contrasted to the single sacral and coxal tubers in large animals.
  • ischial s. (2) the crest of bone to which the sacrosciatic ligament attaches and that provides the origin of the gluteus profundus muscle.
  • plant s’s (1) one or more of which can cause cutaneous laceration and subcutaneous abscess, oral mucosal laceration, and ulceration, conjunctival injury.
  • scapular s. (1) the ridge that divides the lateral surface of the scapula into the supraspinous and infraspinous fossae.

• spinifugal [spi-nif′u-g l] conducting or moving away from the spinal cord.

• spinipetal [spi-nip′ -t l] conducting or moving toward the spinal cord.

• spinners type said of wool that is attractive to makers of yarns.

  S-73.

  

  Distinguishing anatomic landmarks of the cervical spine.

• spinning top a device used to assess the accuracy of the timer on the x-ray machine.

• spinobulbar [spi″no-bul′b r] pertaining to the spinal cord and medulla oblongata.

• spinocellular [spi″no-sel′u-l r] pertaining to prickle cells.

• spinocerebellar [spi″no-ser″ -bel′ r] pertaining to the spinal cord and cerebellum.

  • s. tract a pair of tracts (dorsal and ventral) on each side in the lateral funiculus of the spinal cord carrying proprioceptive impulses from muscles, bones, and joints to the cerebellum.

• Spinoni Italiani a medium- to large-sized, strongly built, all-purpose gun dog with docked tail and a thick, dense wiry coat that forms a mustache and beard. The color is white, orange, or brown with orange or brown markings, and the nose, lips, and eyelids are fleshy red. Called also Italian coarsehaired pointer.

• spinosad an insecticide derived from the actinomycete Saccharopolyspora spinosa; it has a novel mode of action on the nicotinic acetylcholine D alpha receptors with some effects on GABA, causing nerve excitation, paralysis, and rapid death of the flea. Administered orally, once monthy, to dogs as a flea adulticide.

• spinose ear tick [spi′nōs] Otobius megnini.

• spinothalamic tract [spi″no-th -lam′ik] two spinal cord tracts carrying afferent nerve fibers to the thalamus; includes two principal tracts, the lemniscal and the extralemniscal systems.

• spinous [spi′n s] pertaining to or like a spine.

  • dorsal s. processes processes of the vertebrae that underlie the backline of the animal.
  • s. layer see stratum spinosum.
• spiny sharp spines protrude.

  • s. clotburr Xanthiumspinosum.
  • s. emex see Emex australis.

• spiracle [spir′ -k l] small, circular or oval openings in the exoskeleton of insects and archnids that are the portal of entry for air into the tracheal system within the arthropod body.

• spiradenoma [spīr″ad- -no′m] adenoma of the sweat glands.

• spiral [spi′r l] 1. winding like the thread of a screw. 2. a structure curving around a central point or axis.

  • Curschmann’s s’s see Curschmann’s spirals.
  • s. organ of Corti see organ of Corti.
  • s. penile deviation a defect in bulls. See corkscrew penis.
  • s. wormDispharynx nasuta. See Synhimantusspiralis.

• spiramycin [spir″ -mi′sin] a macrolide antibiotic used primarily against penicillin-resistant staphylococci and for mycoplasmal diseases of swine and for swine dysentery. Administered by injection as the adipate ester.

• spireme the thread-like continuous or segmented figure formed by the chromosome material during prophase.

• spirilla [spi-ril′ ] plural of spirillum.

• spirillicidal destroying spirilla.

• spirillicide an agent that destroys spirilla.

• spirillosis [spi″rľ-lo′sis] a disease caused by presence of spirilla. A form of rat-bite fever in humans is caused by Spirillum minus.

• Spirillum [spi-ril′ m] a genus of gram-negative, motile, helical bacteria isolated from fresh water. Neither of the animal pathogens bearing the genus name belong in this genus.

  • S. minus, S. minor pathogenic for guinea pigs, rats, mice, and monkeys and is the cause of ratbite fever (Sodoku).
  • S. pulli recorded as causing a diphtheritic stomatitis in chickens.

• spirillum [spi-ril′ m] pl. spirilla [L.] 1. a spiral-shaped bacterium. 2. A member of the genus Spirillum.

• spirit [spir′it] 1. a volatile or distilled liquid. 2. a solution of a volatile material in alcohol.

  • ammonia s’s, aromatic s’s of ammonia a mixture of ammonia, ammonium carbonate, and other agents once used as a stimulant or alterative for a languishing horse.
  • rectified s. alcohol.

• spir(o)- 1. [Gr.] a combining formdenoting relationship to a coil or spiral. 2. [L.] a combining form denoting relation to the breath or to breathing.

• Spirocerca [spi″ro-ser′k ] a genus of spiruroid nematodes in the family Spirocercidae.

  • S. arctica found in dog, fox, and wolf.
  • S. lupi found in domestic and wild Canidae and wild Felidae. The worms are located in the walls of the esophagus, the aorta, and, the stomach, and sometimes in other organs, persisting in nodules. The nodules may be large enough to cause obstruction of the esophagus and the aorta. The esophageal lesion converts to a fibrosarcoma or an osteosarcoma in a number of cases.
  • S. sanguinolenta see S. lupi (above).
• Spirocerca [spi″ro-ser′k ] a genus of spiruroid nematodes in the family Spirocercidae.

  • S. arctica found in dog, fox and wolf.
  • S. lupi found in domestic and wild Canidae and wild Felidae. The worms are located in the walls of the esophagus, the aorta and, the stomach, and sometimes in other organs, persisting in nodules. The nodules may be large enough to cause obstruction of the esophagus and the aorta. The esophageal lesion converts to a fibrosarcoma or an osteosarcoma in a number of cases.
  • S. sanguinolenta see S. lupi (above).

• spirocercosis [spi″ro-s r-ko′sis] see Spirocerca lupi.

• Spirochaeta a genus of the family Spirochaetaceae of bacteria. Gram-negative, facultatively or obligately anaerobic bacteria.

  • S. anserina now called Borrelia anserina; causes fowl spirochetosis.
  • S. penortha of uncertain taxonomic status; described as a cofactor in ovine footrot.

• spirochaetosis see spirochetosis.

  S-74.

  

  (A) Caudal esophagus of a dog showing mutliple parasitic nodules (white arrows) with red adult Spirocera lupi worms (black arrows). Bar=5.5 cm. (b) Caudal esophagus of a dog showing a cauliflowerlike mass which is a Spirocerca lupi associated osteosarcoma with regional megaespohagus. Bar= 5 cm.

  S-75.

  

  Spirocerca lupi, nodules in the esophageal wall of a dog.

• spirochete [spi′ro-kēt] 1. a highly coiled bacterium; a general term applied to any organism of the order Spirochaetales, which includes the causative organisms of human syphilis (Treponema pallidum), of avian spirochetosis (Borrelia anserina), and rabbit spirochetosis (Treponema paraluiscuniculi), and associated with swine dysentery (Brachyspira hyodysenteriae) and digital dermatitis of cattle (Treponema spp.). 2. an organism of the genus Spirochaeta.

• spirocheticide an agent that destroys spirochetes.

• spirochetolysis the destruction of spirochetes by lysis.

• spirochetosis [spi″ro-ke-to′sis] 1. infection with spirochetes. 2. leptospirosis.

  • avian intestinal s. caused by Brachyspira pilosicoli, B. intermedia, and B. alvinipulli, is primarily a disease of layer and broiler breeder chickens exhibited by delayed and/or reduced egg production, increased mortality, weight loss, and chronic diarrhea, but is recorded in adult duck and goose flocks.
  • fowl s. an infectious disease of many species of fowl caused by Borrelia anserina and characterized by fever, cyanosis of the head, and diarrhea. It is transmitted by the fowl ticks Argas persicus, A. miniatus and A. reflexus. Morbidity and mortality are very variable but may reach 100%.
  • venereal s. of rabbits a benign venereal disease of rabbits caused by Treponema paraluiscuniculi, characterized by small vesicles, scabs, or ulcers that heal in 10–14 days. The lesions are confined to the genitalia, with a few animals also having lesions on the eyelids and lips. Called also rabbit syphilis, treponematosis, vent disease.

• spirogram [spi′ro-gram] a graph of respiratory movements made by the spirometer.

• spirograph [spi′ro-graf] an apparatus for measuring and recording respiratory movements.

• spiroid [spi′roid] resembling a spiral.

• spirometer [spi-rom′ -t r] an instrument for measuring air taken into and expelled from the lungs. The spirometer provides a relatively simple method for determining most of the lung volumes and capacities that are measured in pulmonary function tests.

• Spirometra [spi″ro-me′tr ] diphyllobothriidean tapeworms similar to Diphyllobothrium spp. that occurs in the intestines of wild carnivores and domestic cats and dogs. The larval stages (plerocercoids) infect amphibians, reptiles, and mammals, but humans can also be infected, the resulting disease being known as sparganosis. Includes S. erinacei (cats, dogs) (also known as S. europaerinacei), S. mansoni (cats, dogs), S. mansonoides (cats, dogs, raccoons), S. reptans (New World primates), although specific identification is currently not particularly reliable.

• spirometry [spi-rom′ -tre] measurement of the breathing capacity by means of a spirometer.

• spironolactone [spi″r -no-lak′tōn] a competitive antagonist of aldosterone, used as a potassium-sparing diuretic.

• Spironucleus a genus of diplomonad flagellates of the family Hexamitidae that inhabit the alimentary tract of animals. Species were formerly included in Hexamita.

  • S. meleagridis pathogen of turkeys, pheasants, peafowl, and quail. An additional species, S. columbae occurs in pigeons.
  • S. muris a protozoan of mice. It causes weight loss, diarrhea, and sometimes death.
  • S. salmonicida a significant pathogen of salmon. Six other species are known from fish including S. salmonis from trout and species causing disease in ornamental fish.

• Spiroptera incerta [spi-rop′t r-] see Habronema incertum.

  S-76.

  

  Rabbit spirochetosis (syphilis). Young adult female rabbit with typical mild to moderate case of rabbit syphilis. Lesions are near mucocutaneous junctions.

• Spirura a genus of nematodes in the family Spiruridae found in the alimentary tract of carnivores, rodents, and insectivores.

  • S. rytipleurites there are two varieties, one found in the stomach of the cat and fox and one in the hedgehog.
  • S. talpae found in the European common mole (Talpa europea) and the black rat Rattus rattus.

• spiruroid roundworms of the order Spirurida. Includes the genera of Cyrnea, Draschia, Habronema, Hartertia, Mastophorus, Protospirura, Spirura, Streptopharagus.

• spit defensive expulsion of fluid material from the mouth of camelids. There are two kinds of spitting: saliva, usually ejected with the camelid’s head tilted upward, as a warning; or of viscous, green content from the first compartment, usually aimed directly at the head or body of the offending camelid or human. The first kind is innocuous, the second, malodorous and memorable.

  • s. off repeated spitting activity of a female to a male camelid to warn away the male suitor. A female who spits off a male might be indicating that she is pregnant.

• spitz a general description of so-called ‘Northern’ or Nordic dog breeds with conformational characteristics resembling wolves. They have bushy tails carried upright or over the back, thick short stand-off coat with a ruff around the neck, a wedge-shaped head, and small pricked ears. Characteristic of a number of dog breeds. See also American spitz, Canaan dog, Canadian Eskimo dog, Eurasier, Finnish Lapphund, Finnish spitz, German spitz, Hokkaido, Japanese Shiba inu, Japanese spitz, Norwegian buhund, Swedish Lapland dog.

• splake trout hybrids of the brook trout (male) and lake trout (female) (S. fontinalis x S. namaycush).

• splanchnapophysis a bony process, such as a ventral process on certain vertebrae, that is associated with the viscera.

• splanchnectopia displacement of a viscus or of the viscera.

• splanchnesthesia [splank″nes-the′zh ] visceral sensation.

• splanchnic [splank′nik] pertaining to the viscera.

  • s. circulation includes the mesenteric, splenic, and hepatic beds, the first two comprising the major part of the inflow to the third.
  • s. nerves a group of sympathetic nerves serving the blood vessels and viscera of the abdomen.

• splanchnicotomy [splank″nľ-kot′ -me] transection of a splanchnic nerve.

• splanchn(o)- word element. [Gr.] relationship to viscera.

• splanchnocele [splank′no-sēl] hernial protrusion of a viscus. The portion of the embryonic body cavity from which the abdominal, pericardial, and pleural cavities are formed.

• splanchnocoele splanchnocele.

• splanchnodiastasis displacement of a viscus or viscera.

• splanchnolith intestinal calculus.

• splanchnology [splank-nol′ -je] science of the organs of the body, as of the digestive, respiratory, and genitourinary systems.

• splanchnomegaly [splank″no-meg′ -le] enlargement of the viscera; visceromegaly.

• splanchnopathy any disease of the viscera.

• splanchnopleure [splank′no-ploor] the embryonic layer formed by union of the splanchnic mesoderm with endoderm; the digestive tube develops from it.

• splanchnoptosis prolapse or backward displacement of the viscera.

• splanchnosclerosis hardening of the viscera.

• splanchnoskeleton skeletal structures connected with viscera.

• splanchnotomy [splank-not′o-me] anatomy or dissection of the viscera.

• splanchnotribe an instrument for crushing the intestine to obliterate its lumen.

• splashing an abattoir term for large areas of hemorrhage in the form of brush marks or groups of spots, usually evident in muscles and under serous membranes.

• splayed digits an inherited defect in cattle in which the tendons and ligaments that hold the claws of the foot together are relaxed so that the digits splay. There is difficulty in standing and walking and affected animals lie down most of the time.

• splayleg [spla′leg] a congenital defect of the hindlimbs of piglets that prevents standing. The piglet is in sternal recumbency with the hindlimbs splayed and can only make swimming movements in attempts to rise. Some are crushed by the sow. Called also myofibril hypoplasia, spraddleleg. Occurs also in rabbits.

• spleen [splēn] a large lymphoid organ usually situated in the cranial part of the abdominal cavity on the left of the stomach. The spleen contains the largest collection of reticuloendothelial cells in the body. In ruminants the spleen is located on the left lateral wall of the rumen and reticulum and under the last two ribs on the left side. Called also lien.

  S-77.

  

  Splayleg.

  • accessory s. a small mass of tissue, histologically and functionally identical with that composing the normal spleen but found elsewhere in the body.
  • sago s. see sago spleen.
  • slaughter s. see slaughter spleen.

• splenadenoma nodular hyperplasia of the spleen pulp.

• Splendidofilaria a genus of filarioid nematodes parasitic in birds; Ornithofilaria is a synonym of Splendidofilaria.

• Splendore–Hoeppli material [splen-dor′ra hur′ple] dense intensely eosinophilic radiating club-shaped deposits around foreign material and infectious agents (fungi, bacteria, and parasites). Seen in actinomycosis, actinobacillosis, botryomycosis, and nocardiosis. Derived from degraded antigen-antibody complexes. See also club colony.

• splenectasis [sple-nek′t -sis] splenomegaly.

• splenectomy [sple-nek′t -me] excision of the spleen. Most commonly performed in dogs and cats because of trauma or neoplasia.

• splenectopia, splenectopy [sple″nek-to′pe- ] see splenic displacement.

• splenial [sple′ne- l] pertaining to a splenium (anatomical).

• splenic [splen′ik] pertaining to the spleen.

  • s. abscess caused by hematogenous spread of an infection elsewhere, by penetration by a foreign body from the reticulum in cattle, by ulceration from the stomach in the horse. Manifested by fever and toxemia, pain on palpation over the spleen, and by evidence of inflammatory change in an abdominocentesis sample.
  • s. corpuscle lymph nodules in the splenic matrix.
  • s. displacement abnormal location of a previously appropriately place spleen. may be detectable on palpation. Usually caused by displacement of the stomach or intestine to which the spleen is attached.
  • s. enlargement see splenomegaly.
  • s. fever anthrax.
  • s. hyperfunction see hypersplenism.
  • s. rupture occurs with abdominal trauma in dogs and cats or with little or no trauma with a grossly enlarged spleen, e.g., splenic neoplasm or in bovine viral leukosis.
  • s. torsion a twisting or rotation of the spleen on its vascular pedicle, often in association with gastric dilatation–volvulus in large-breed dogs, results in primarily venous congestion and possibly thrombosis and infarction. Clinical signs include abdominal distention and pain, vomiting, and in acute cases, cardiovascular collapse and shock.

• splenitis [sple-ni′tis] inflammation of the spleen, a condition that is attended by enlargement of the organ and severe local pain. Is usually a diffuse suppurative infection.

• splenium [sple′ne-um] band-like structure.

  • s. corporis callosi the posterior, rounded end of the corpus callosum.

• splen(o)- word element. [Gr.] relationship to the spleen.

• splenocele [sple′no-sēl] hernia of the spleen.

• splenocolic [sple″no-kol′ik] pertaining to the spleen and colon.

• splenocyte [sple′no-sīt] the monocyte characteristic of splenic tissue.

• splenography [sple-nog′r -fe] radiography of the spleen.

• splenohepatomegaly [sple″no-hep″ -to-meg′ -le] enlargement of the spleen and liver.

• splenoid [sple′noid] resembling the spleen.

• splenolysin a lysin that destroys spleen tissue.

• splenolysis [sple-nol′ľ-sis] destruction of splenic tissue by a lysin.

• splenoma [sple-no′m ] a splenic tumor.

• splenomalacia [sple″no-m -la′sh] abnormal softness of the spleen; lienomalacia.

• splenomedullary [sple″no-med′u-lar″e] of or pertaining to the spleen and bone marrow; lienomedullary.

• splenomegaly [sple″no-meg′ -le] enlargement of the spleen. Is largely without clinical signs but it can be palpated during an examination through the abdominal wall in dogs and cats, rectally in horses and not at all in ruminants. The enlargements can be caused by abscess or neoplasia, infectious disease (notably anthrax) or administration of some pharmacologic agents (such as barbiturates).

  • asymmetrical s. usually the result of trauma or neoplasia.
  • congestive s. in animals, most often caused by splenic torsion.
  • hemolytic s. that associated with hemolytic anemia.
  • siderotic s. splenomegaly with deposit of iron and calcium.
  • symmetrical s. usually caused by congestion or infiltration of the splenic tissue.

• splenometry [sple-nom′ -tre] determination of the size of the spleen.

• splenomyelogenous [sple″no-mi″ -loj′-n s] formed in the spleen and bone marrow; lienomyelogenous.

• splenomyelomalacia [sple″no-mi″ -lo-m-la′sh] softening of the spleen and bone marrow; lienomyelomalacia.

• splenopancreatic [sple″no-pan″kre-at′ik] pertaining to the spleen and pancreas.

• splenopathy [sple-nop′ -the] any disease of the spleen.

• splenopexy [sple′no-pek″se] surgical fixation of the spleen to prevent torsion of the spleen around the splenic pedicle.

• splenopneumonia pneumonia attended with splenization of the lung.

• splenoportography [sple″no-por-tog′r -fe] radiography using a radiopaque contrast agent injected into the pulp of the spleen to demonstrate portosystemic vascular anomalies.

• splenoptosis [sple″nop-to′sis, sple″no-to′sis] backward displacement of the spleen.

• splenorenal [sple″no-re′n l] pertaining to the spleen and kidney, or to splenic and renal veins.

• splenorrhagia [sple″no-ra′j ] hemorrhage from the spleen.

• splenorrhaphy [sple-nor′ -fe] suture of the spleen.

• splenosis [sple-no′sis] widespread seeding of splenic implants on the serosal surfaces in the abdominal cavity; follows rupture of spleen, commonly after trauma.

• splenotomy [sple-not′ -me] incision of the spleen.

• splenotoxin [sple′no-tok″sin] a toxin produced by or acting on the spleen; lienotoxin.

• spliceosome [spli′so-sōm] a ribonucleoprotein complex involved in the splicing of RNA.

• splicing [spli′sing] of RNA, the excision of introns from the primary transcript and the joining together of exons to make their finished mRNA. See also ribonucleic acid.

• splint [splint] 1. a rigid or flexible appliance for fixation of displaced or fractured bones, or to support soft tissue structures such as the Achilles tendon or collateral ligaments post-surgery or following trauma. 2. see also splints.

  • biphase s. an external mandibular splint used to stabilize fractures. It consists of fixation bolts placed in the mandible with an acrylic bar placed across the protruding ends, parallel to the mandible.
  • gutter s. one with a central channel into which the well-padded limb is placed for support of a fracture.
  • half-pin s. open reduction fracture repair based on placing Steinmann pins through the cortex and at an acute angle to the bone, in both sides of the fracture. The pins are connected to each other with rods that are then locked together with a Kirschner clamp, the fracture reduced, and the pin-clamp assembly readjusted. Half-pin systems include Jonas and Kirschner.
  • Kirschner–Ehmer s. see Kirschner–Ehmer splint.
  • lateral s. rigid splinting material such as plaster is applied to the lateral surface of a limb covered in a soft padded bandage to provide support and protection from angular or bending forces.
  • metal rod s. aluminum rods, bent to conform to the angles of the limb, are incorporated into the outer layers of a soft padded bandage to provide support and protection from angular or bending forces.
  • modified spica s. similar to a lateral splint, but the bandaging and splinting is more extensive, being carried over the shoulder or hip and across the dorsal midline. Used to immobilize the humerus or femur, temporarily or as an adjunct to internal fixation.
  • Robert-Jones s. see Robert-Jones bandage.
  • Schroeder–Thomas s. a traction splint, made of aluminum rods and consisting of a padded ring with extended bars bent to a shape determined by the size of animal and type of fracture. The limb is suspended and traction applied to the joints proximal and distal to the fracture site by wrapping with padded bandages. Modified versions are used for radial and tibial fractures in large animals.
  • snowshoe s. molded to fit the bottom of an avian foot, it is suitable for supporting fractures of the digits in those species.
  • spoon s. concave channel splints of metal or plastic, commonly used over soft padding for fractures of the lower limb in dogs and cats. Called also metasplint.
  • Stader s. the original half-pin splint now largely superseded by the Kirschner splint. The pins have to be placed in the bone fragments in the position dictated by the configuration of the blocks into which the pins are fastened.
  • tape s. support with tape can be used on leg fractures in birds.
  • Thomas s. see Schroeder–Thomas splint (above).
  • traction s. see Schroeder–Thomas splint (above).

• splint bone the second and fourth metacarpals or metatarsals of the horse that are greatly reduced in size and do not extend as far as the distal end of the third metacarpal.

• splinting [splin′ting] 1. the application of a splint to reduce a fracture or to restrict movement. 2. tensing of muscles, especially ventral abdominal muscles, as a response to pain and as a protection against further injury.

  • s. materials used in splinting fractures. Includes plaster, fiberglass, wood, balsa wood, aluminum rod, steel pins, nails, plates, screws.

• splints [splints] inflammation of the interosseous ligament between the small and large metacarpal bones of horses and an accompanying periostitis and exostosis production on the small metacarpal bone. The metatarsal bones are similarly but less frequently involved. Lameness is apparent during the development of the splints and is most noticeable after working. Subsequently the soreness disappears but the enlargement can be palpated, and seen in the worst cases.

• split divided.

  • s. fats fats that have been split into fatty acids and glycerol by digestion. A preponderance of split fats over neutral fats in the feces suggests that the supply of lipase is adequate and that any steatorrhea that is present is probably due to malabsorption rather than maldigestion.
  • s. hand deformity see ectrodactyly.
  • s. pawpad disease a rare syndrome in dogs characterized by splitting and peeling of the keratin layer of footpads with lesions aggravated by pain and self-trauma; lameness is variable. The cause is unknown.

• SpO² percentage of hemoglobin that is oxygen-saturated, measured in peripheral capillary blood by pulse oximetry.

• spodogenous caused by accumulation of waste material in an organ.

• spoilage decomposition; said of meat, milk, where it is most frequently determined by the activity of microorganisms, which results in the development of off-odors, gas, and slime, but also influenced by biochemical factors such as lipid radical chain and pigment oxidation causing undesirable flavors. Also said of animal feeds especially silage.

  S-78.

  

  Modified Thomas splint.

  • chemical s. occurs in preserved foods, especially canned ones. Is usually the result of interaction between the contents and an imperfect container. There may be gas produced, e.g., hydrogen swells, or discoloration of the tin.

• spondylarthritis [spon″d l-ahr-thri′tis] arthritis of the spine.

• spondylitic [spon″d -lit′ik] pertaining to or marked by spondylitis.

• spondylitis [spon″d -li′tis] inflammation of the vertebrae. See also spondylosis, diskospondylitis.

• spondyl(o)- word element. [Gr.] relationship to vertebra, vertebral column.

• spondyloarthropathy [spon″d -lo-ahr-throp′ -the] disease of the joints of the spine.

• spondylodynia [spon″d -lo-din′e-] pain in a vertebra.

• spondyloepiphyseal dysplasia [spon″d -lo-ep″ľ-fiz′e- l] see epiphyseal dysplasia.

• spondylolisthesis [spon″d -lo-lis-the′sis] forward displacement of a vertebra over a posterior segment due to a congenital defect or fracture in the pars interarticularis. Occurs in the giant breeds of dogs as (cervical spondylomyelopathy or wobbler syndrome) and, historically, as a developmental defect called kinky back in broiler chickens. Affected birds are unable to stand normally and may be completely paralyzed. The causative lesion is a deformity of the sixth thoracic vertebra but the cause of the defect is unknown.

• spondylolysis [spon″d -lol′ľ-sis] the breaking down of a vertebra.

• spondylopathy [spon″d -lop′ -the] any disease of the vertebrae. Associated with compression of peripheral nerve roots and spinal cord, causing pain and stiffness of the part. See also spondylitis, spinal abscess, spondylosis.

  • cervical s. see cervical spondylomyelopathy.

• spondylopyosis [spon″d -lo-pi-o′sis] suppuration of a vertebra.

• spondyloschisis [spon″dľ-los′kľ-sis] congenital fissure of a vertebral arch; spina bifida.

• spondylosis [spon″d -lo′sis] ankylosis of a vertebral joint; also, a general term for degenerative changes in the spine. Commonly seen in dogs. In aged bulls, spondylosis can cause pain in the back. There is difficulty rising, weakness, unsteadiness, knuckling, and toe-dragging with the hind hooves.

  • s. deformans a chronic disease of the vertebrae, especially in the lumbar area, in old bulls, especially those in artificial insemination centers, and dogs. There is degenerative arthropathy at the articular processes and osteophyte development along the ventral edge of the vertebrae. The lesions are visible radiographically, but there may be no clinical signs unless the new bone is injured. When this happens, the affected animals are reluctant to rise or move their backs because of the pain that movement causes.

• spondylosyndesis [spon″d -lo-sin-de′sis] surgical creation of ankylosis between contiguous vertebrae; spinal fusion.

• sponge [spunj] a porous, absorbent mass, as a pad of gauze or cotton surrounded by gauze, or the elastic fibrous skeleton of certain species of marine animals.

  • s. forceps see Foerster sponge forceps.
  • gelatin s. (absorbable) a spongy form of denatured gelatin, soaked with thrombin and used for topical hemostasis.
• spongiform [spun′jľ-form] resembling a sponge.

  • s. encephalopathy a disease of the brain having the microscopic appearance of a sponge. The transmissible spongiform encephalopathies (TSEs) of animals and humans are Creutzfeldt-Jakob disease in humans and its variant, Gertstmann-Straussler-Scheinker disease in humans, kuru, fatal familial insomnia of humans, scrapie in sheep, goats, and moufflon, transmissible encephalopathy of mink, chronic wasting disease of deer and elk, bovine spongiform encephalopathy (BSE), TSE of zoo ungulates, hereditary canine spongiform encephalopathy in Rottweilers, and feline spongiform encephalopathy.

• spongi(o)- word element. [L., Gr.] sponge, sponge-like.

• spongioblast [spun′je-o-blast] any of the embryonic epithelial cells developed about the neural tube, which become transformed, some into neuroglial and some into ependymal cells.

• spongioblastoma [sp n″je-o-blas-to′m] a tumor containing spongioblasts; a type of astrocytoma.

  • polar s. an astrocytoma with a predilection for the optic nerve and pons.

• spongiocyte [spun′je-o-sīt″] 1. a neuroglia cell. 2. one of the cells with spongy vacuolated protoplasm in the adrenal cortex.

• spongioform spongiform.

• spongioid [spun′je-oid] resembling a sponge.

• spongioplasm 1. a substance forming the network of fibrils pervading the cell substance and forming the reticulum of the fixed cell. 2. the granular material of an axon.

• spongiosa [spun″je-o′s ] spongy; sometimes used alone to mean the spongy substance of bone (substantia spongiosa ossium).

  • primary s. the mineralized cartilage in the developing metaphysis.
  • secondary s. second stage in the mineralization of bony trabeculae; comprises the enlarged, mineralized bony trabeculae of the primary spongiosa.

• spongiosaplasty [spun″je-o′s -plas″te] autoplasty of the spongy substance of bone (substantia spongiosa ossium) to potentiate formation of new bone or to cover bone defects; cancellous bone graft.

• spongiosis [spun″je-o′sis] intercellular edema within the epidermis; also describes intramyelinic edema in central nervous tissue.

• spongiositis [spun″je-o-si′tis] inflammation of the corpus spongiosum of the penis.

• spongy [spun′je] of spongelike appearance or texture.

  • s. degeneration see spongy degeneration.
• spontaneous [spon-ta′ne- s] having no apparent external cause.

  • s. abortion most animal abortions are spontaneous in contradistinction to the surgically and medically procured abortions of humans. See also mismating, parturition induction.
  • avian s. cardiomyopathy an idiopathic disease of 1-to 4-week-old turkey poults causing sudden death or a brief period of dyspnea; the heart is visibly dilated.
  • s. internal hemorrhage causes sudden death in most cases; causes include cardiac tamponade, aortic or atrial rupture, splenic rupture.
  • s. pneumothorax occurring without any identifiable inciting cause
  • s. pulmonary arteriopathy see pulmonary arteriopathy.
  • s. regression when diseases resolve themselves without outside assistance.
  • s. virus encephalitis so called because the disease appears without the subject animal coming in contact with a known encephalitogenic agent. In most instances, the occurrence is eventually explained by the presence of a hitherto unknown virus.

• spoodles a hybrid name used to describe dogs produced from crossing Cocker spaniels and Poodles. Not a recognized breed. See designer dogs.

• sporadic [sp -rad′ik] occurring irregularly, usually infrequently.

• sporadic leukosis leukosis of cattle that is other than bovine viral leukosis.

  • bovine s. l. occurs sporadically in animals less than 3 years old. There is a cutaneous form with temporary skin plaques that ultimately becomes systemic, a juvenile or calf form with multiple lymph node enlargement, and a thymic form with compression of the jugular veins and brisket and submandibular edema.
  • equine s. l. characterized by subcutaneous and lymph node enlargements, jugular vein engorgement, cardiac irregularity, exophthalmos, and anasarca or with diffuse involvement of the small intestine.
  • ovine s. l. characterized by lymph node enlargement, jugular vein engorgement, and hepatosplenomegaly; caused by bovine leukemia virus.
  • porcine s. l. characterized by emaciation, weakness, anorexia, bone marrow involvement, and hepatosplenomegaly.

• sporadic lymphangitis [sp -rad′ik lim-fan″je-i′tis] a noncontagious disease of horses characterized by a sudden onset of severe swelling and pain in one hindleg. There is a high fever. Associated with infection of minor wounds on the leg, a lymphangitis and lymphadenitis, and spread of infection to surrounding tissues. Called also bigleg, sporadic equine lymphangitis.

• sporangia structures containing the spores of fungi. See also spherules.

• sporangiophore [sp -ran′je-o-for] a specialized hypha that gives rise to a sporangium.

• sporangium [sp -ran′je- m] any cyst that contains spores or spore-like bodies.

• spore [spor] 1. a refractile, oval or spherical body formed within bacteria, especially Bacillus and Clostridium spp., usually under adverse conditions such as nutritional deprivation, and that is regarded as a fully infectious, resting stage in the life cycle of the cell. Spores are inactive metabolically, highly resistant to environmental changes and may survive, for example, in soil, for many years. Bacterial spores come in various shapes and are given illustrative names such as drumstick, terminal, and subterminal. 2. the reproductive element, produced sexually or asexually, of organisms, such as protozoa, fungi, or algae.

  • s. former a bacteria or other small life form that forms spores.

• sporicide [spor′ľ-sīd] an agent that kills spores.

• sporidesmin [spor″ľ-des′min] pyrrolidine metabolites of the fungus Pithomyces chartarum that cause facial eczema in sheep and cattle.

• Sporidesmium bakeri see Pithomyces chartarum.

• sporoblast [spor′o-blast] an asexual reproductive phase in the development of some protozoan parasites. Occurs prior to the development of the sporozoites. See also sporogony.

• sporocyst [spor′o-sist] 1. any cyst or sac containing spores or reproductive cells; contained in the oocyst of coccidia in which sporozoites develop; 2. a larval stage of flukes (digenetic trematodes) in snails.

• sporogenic [spor″o-jen′ik] producing spores.

• sporogony [sp -rog′ -ne] an asexual stage in the life cycle of an apicomplexan parasite, with development of sporocysts and sporozoites within the oocysts. The oocysts are extraintestinal (e.g., Eimeria, Isospora), or intraintestinal (Sarcocystis, Cryptosporidium).

• sporont [spor′ont] an asexual stage of a protozoan parasite, the precursor of the sporozoite. See also sporogony.

• sporoplasm [spor′o-plaz- m] the protoplasm of a spore.

• Sporothrix a genus of dimorphic fungi in the phylum Ascomycota.

  • S. carnis causes white mold on meat in storage.
  • S. schenckii (syn. Sporotrichum schenckii, S. beurmonsis, S. beurmanii, S. equi, Ceratocystis stenoceras) a saprotrophic species found in soil and decaying vegetation. Causes sporotrichosis, a chronic mycosis of the cutaneous, subcutaneous, and lymphatic tissues.

• sporotrichin [sp -rot′rľ-kin] a substance present in old broth cultures of Sporothrix schenckii and capable of eliciting a specific delayed-type hypersensitivity reaction in infected animals.

• sporotrichosis [spor″o-trľ-ko′sis] a contagious disease in many species, including humans, caused by Sporothrix schenckii complex. It may occur in a cutaneous form, as localized, ulcerated nodules; a cutaneous–lymphatic form, seen particularly in horses as cutaneous nodules on the lower limbs, which may be connected by corded lymphatics and that discharge pus and then heal; or a disseminated form with infection of deep tissues, bone, and viscera.

• Sporotrichum [sp -rot′rľ-k m] see Sporothrix.

• Sporozoa [spor″o-zo′ ] previously considered a subphylumof endoparasitic protozoa; now referred to as the phylum Apicomplexa. Protozoa in this phylum usually have complex life cycles, involving three main phases: schizogony (asexual), gametogony (sexual), and sporogony (asexual).

• sporozoa [spor″o-zo′ ] plural of sporozoon.

• sporozoan [spor″o-zo′ n] 1. pertaining to the phylum Apicomplexa (class Sporozoa). 2. an individual of the Sporozoa.

• sporozoite [spor″o-zo′īt] a spore formed after fertilization; a sickle-shaped nucleated stage formed by division of the protoplasm during sporogony (asexual replication) of an apicomplexan parasite. The sporozoite is an infective stage (e.g., Eimeria, Cryptosporidium).

  S-79.

  

  Sporotrichosis. Ulceration of subcutaneous and lymphatic nodules.

• sporozoon [spor″o-zo′on] pl. sporozoa [Gr.] an individual organism (protist) of the class Sporozoa. Generally classified within the Apicomplexa.

• sport see mutation (2).

• sport hunting hunting without collection of a food or other commercial product; hunting for trophy or prize.

• sporting dog see gun dog.

• sporulation [spor″u-la′sh n] formation of spores in protozoans and fungi or sporozoites in protozoans.

• spot [spot] a small, roundish part of a surface that differs from the surrounding surface.

  • s. disease of turtles. See shell rot.
  • s. map a map with dots on it. Each dot marks where a case or some other incident of epidemiological interest occurred.
• spot film see spot film.

  • s. film device a device attached to the x-ray machine that moves an x-ray cassette into position for exposure during a fluoroscopic examination.

• spot-on a means of delivering medication topically, usually in a small area of the skin, where the active ingredient is absorbed percutaneously. A method used particularly for flea control agents.

• spotted characterized by spots.

  • s. dick see Dalmatian.
  • s. emu bush Eremophilamaculata.
  • s. fever a febrile disease characterized by a skin eruption, such as Rocky Mountain spotted fever, boutonneuse fever, and other human infections due to tickborne rickettsiae.
  • s. fever tick Dermacentorandersoni.
  • s. fuschia Eremophilamaculata.
  • s. horse see Appaloosa.
  • s. mist a cat breed. See Australian mist.

• spraddleleg, spraddle limb see splayleg.

• sprain [sprān] wrenching or twisting of a joint, with partial rupture of its ligaments. There can also be damage to the associated blood vessels, muscles, tendons, and nerves. A sprain is more serious than a strain, which is the overstretching of a muscle, without swelling. Severe sprains are so painful that the joint cannot be used. There is much swelling owing to hemorrhage from ruptured blood vessels.

• sprained tendon see bowed tendon, tendon strain.

• Spratt bone curette a single ended instrument with a round cup of various sizes on the end.

• spray [spra] material applied in liquid form by pressure through a fine orifice creating a mist of fine droplets, e.g., insecticidal spray in a spray dip, pressure pack spray of insecticide, or wound treatment.

  • s.-dehydrated a substance that has been dried by spraying onto a revolving heated drum and retrieved by scraping it from the drum.
  • s. drift chemical spray being applied to an agricultural crop may be toxic to animals and be carried from its target by wind. Poisoning by organophosphates and arsenic has been caused in this way.
  • s. freezing direct application of freezing agent, e.g., liquid nitrogen, by fine spray or stream.
  • s. race a lane with high fences, see race (2), used to restrain animals while they are being sprayed, usually with insecticide.

• spraydip device for applying insecticide or other solution to the coat of animals, replacing the plunge dip. The animal walks through a compartment that carries spray nozzles on the sides, below and above. Excess spray drains into a sump and is reused.

• spraying the pattern of urination typical of male cats but occasionally seen in females; after backing up to a vertical surface and while holding their tail erect, they void urine in a stream posteriorly onto the object. A form of olfactory communication, especially territorial marking. Called also urine marking.

  • inappropriate s. spraying on household objects. A common behavioral problem in domestic cats; may be related to stress or overcrowding, but sometimes it is caused by urinary tract disease.

• spreading factor said of biological fluids used in pharmaceutical preparations. See hyaluronidase.

• spring rise [spring] a phenomenon in some nematode infestations, e.g., Trichostrongylus, Teladorsagia, in ruminants in which there is an increase in the number of eggs excreted in the feces of ewes during the spring months associated with parturition. Occurs in autumn when lambing is in autumn. Preferably referred to as the periparturient rise in egg counts.

• spring round-up [spring] traditional round-up (muster) each spring on beef cattle ranches to brand, dehorn, castrate the new calf crop, and to draft off the yearlings into the group to be marketed.

• spring viremia of carp [spring] an infection of carp caused by a Rhabdovirus carpio that occurs when water temperature rises in the spring and with environmental disturbances. It is characterized by generalized edema and hemorrhages with exophthalmus (pop eye), and a swollen abdomen (dropsy). There are pathognomonic pinpoint hemorrhagic lesions on the swim bladder. There is often concurrent bacterial infection, particularly with Aeromonas spp. Important in European carp culture. A disease notifiable to the OIE (see Table 21).

• springbok (Antidorcas marsupialis) a medium-sized, gazelle-like antelope, native to South and Southwestern Africa, with distinctive color and markings. The upper body is reddish-tan, and the lower body is white with a wide, dark, diagonal stripe where the two colors meet. The horns are curved and medium length. Hunted as game for skin and meat.

• springbokbush see Hertia pallens.

• springer a North American term commonly used to describe heifers close to term with their first calf.

• Springer spaniel see English springer spaniel, Welsh springer spaniel.

• sprouted grain used as feed; see hydroponics.

• sprue [sproo] a chronic form of malabsorption syndrome in humans occurring in two forms, tropical, which is associated with ingestion of gluten-containing foods (called also celiac disease), and nontropical. Malabsorption syndromes in dogs are sometimes compared with, but are not identical with, sprue. See gluten-sensitive enteropathy of Irish setters.

• Spumaretrovirinae a subfamily of viruses in the family Retroviridae.

• Spumavirus [spu′m -vi″r s] a genus of the family Retroviridae. Spumaviruses, which are also called foamy viruses, are nonpathogenic exogenous viruses that have characteristic morphology with prominent surface spikes. The virions contain significant amounts of double-stranded, full-length DNA, and their assembly is unusual compared to other retroviruses. As an example, equine foamy virus buds from the membranes within the cytoplasm. Some examples are chimpanzee foamy virus, simian foamy virus, and human foamy virus. When cultured in cell cultures, spumaviruses form characteristic large vacuoles, but there is no disease association in animals.

• spur [spur] 1. an abnormal projecting body, as from a bone. 2. a piece of riding gear worn on the heel of a horserider’s boot and used to urge on a horse to a faster speed by digging the spur into the flank. 3. a sharp, horncovered, bony projection from the shank of male birds of some species. Used as a weapon. Called also metatarsal spur. 4. tracheal spur, the ridge of tracheal cartilage that separates the beginning of the right bronchus from the beginnings of the left one.

  • s. veins subcutaneous veins visible over the ventral part of the chest of a horse (superficial thoracic vein). Subject to laceration by indiscriminate use of sharp spurs by the vigorous rider.

• spurge common name for plants in several genera in the family Euphorbiaceae. Includes spurge olive (Daphne mezereum), caper spurge (Euphorbia lathyrus), Gascoyne spurge (E. boophthona), mat spurge (E. drummondii), petty spurge (E. peplus), sun spurge (E. helioscopia), white-margined spurge (E. marginata).

• spurious [spu′re- s] simulated; not genuine; erroneous, particularly when referencing laboratory test results

• sputum [spu′t m] mucous secretion from the lungs, bronchi, and trachea that is ejected through the mouth by humans but not so in animals, and it is assumed that it is swallowed.

  • s. cup a small—1-in.-diameter—cup on a long handle for the collection of sputum from the pharynx of a large animal.
  • s. specimen a sample of mucous secretion from the bronchi and lungs. The specimen may be examined microscopically for the presence of malignant cells, inflammatory cells, and infectious agents (cytological examination) or tested to identify pathogenic bacteria (bacteriological examination).

• SPV sheeppox virus.

• SQ, sq medical abbreviation for subcutaneous.

• squab baby or fledgling pigeon.

• squalene [skwah′lān] a triterpenic compound found in a large number of plants and other sources, especially olive oil and shark oil. Has antioxidant, anti-inflammatory, and anti-atherosclerotic properties, decreases hepatic cholesterol and triglycerides and is used as a nutraceutical in human and veterinary medicine and as a vehicle for pharmaceuticals.

• squama [skwa′m ] pl. squamae [L.] a scale, or thin, plate-like structure.

• Squamata an order of animals, the scaly-bodied reptiles, including snakes and lizards.

• squamatization [skwa″m -tľ-za′sh n] flattened, eosinophilic keratinocytes replace basophilic, cuboidal basal cells.

• squame [skwām] a completely matured keratinocyte (corneocyte) usually shed from a squamous epithelial surface. See also dandruff, scale.

• squamoparietal, squamosoparietal [skwa″mo-p -ri′-t l] pertaining to the pars squamosa, or squamous portion of the temporal bone, and the parietal bone.

• squamous [skwa′m s] scaly or plate-like.

  • s. bone the pars squamosa, or squamous portion of the temporal bone.
  • s. cell carcinoma (SCC) a carcinoma arising from squamous epithelium; relatively common, locally invasive and occasionally metastatic. They can arise in any stratified squamous epithelium, and less commonly in mucosa of other epithelial types. See also Bowen’s disease and specific organ locations Squamous cell carcinomas are among the most common skin tumors in dogs and cats. They are particularly common in sunexposed, poorly pigmented areas of skin such as the pinnae, eyelids, or noses of white cats. Tumors are locally invasive and destructive, but are slow to metastasize.
  • s. eddy a common histological pattern in neoplastic and hyperplastic epidermal disorders. They are whorl-like patterns of squamoid cells.
  • s. metaplasia affected cells are converted to a squamous stratified type from the surface of which squames are shed.
  • ocular s. cell carcinoma occurs around the eye and is common in cattle, especially in breeds with little pigment in the eyelids or conjunctiva (Herefords). Sunlight, papilloma virus infection, skin pigmentation, and heredity are all involved susceptibility. Similar malignancies occur on the eye and eyelid of the horse. Called also cancer eye.
  • s. papilloma the common papilloma in all species except cattle and deer. Composed largely of epithelial tissue (in contrast to fibropapillomas), but many lesions are intermediate in type.
  • s. pearl see keratin pearl.

• square knot [skwār] a secure knot made by a single throw of one of the two ends over the other, then a return and another single throw with both ends coming out on the same side of the loop, either both over or both under it. Called also reef knot. See also knot.

• squash Curcurbita.

• Squatina squatina, S. angelus, S. laevis farmed finfish in family Squatinidae; called also angelshark, monk-fish.

  S-80.

  

  Squamous cell carcinoma on the nose of an adult white cat.

  S-81.

  

  Ocular plaque, an early precursor of ocular squamous cell carcinoma. Courtesy of B. Vanselow.

• squeejit Menthasatureioides.

• squill [skwil] the fleshy inner scales of the bulb of the white variety of Drimia maritima; it contains several cardioactive glycosides. The red variety is used as a rat poison.

  • blue s. Merwilla plumbea.
  • Mediterranean s.Drimia maritima.
  • red s. a cardiac glycoside (scilliroside) extracted from the dried bulbs of Drimia maritima. Was used therapeutically as a cardiac stimulant at one time, and was used as a rodenticide. Poisoning, with signs of bradycardia and convulsions, occurs with very large doses.
  • sea s.Drimia maritima.
  • white s. a cardiac glycoside called scillerin A obtained from the plant Drimia maritima.

• squint [skwint] 1. lay term for strabismus. 2. to narrow the palpebral fissure; in animals associated with pain or discomfort.

• squirrel [skwur′ l] rodent in the family Sciuridae; small, mostly herbivorous and varying in color from gray to shiny black, red, and cream, and in size from mouse to large cat. They are distinguished by their fine, dense fur and their bushy, plume-like tails. Includes the tree, flying and ground squirrels, chipmunks, marmots, and prairie dogs.

  • s. fibroma a poxvirus disease caused by a member of the genus Leporipoxvirus in which there are typical subcutaneous fibroma lesions. The virus isolated from the lesions has been used to produce fibroma lesions in rabbits.
  • fox s. (Sciurus niger) this species has a characteristic of inherited porphyria manifested by fluorescence of bones and teeth when viewed under ultraviolet light, and a pink coloration of these and other tissues. There is no photosensitization.

• squirreltail grass see Hordeum.

• SR sedimentation rate.

• S/R in medical records, an abbreviation for stitch, suture, or staple removal.

• Sr chemical symbol, strontium.

• SRH somatotropin releasing hormone (growth hormone–releasing hormone).

• SRMA steroid-responsive meningitis-arteritis.

• SRP signal recognition particle.

• SRS, SRS-A see slow-reacting substance.

• ss. [L.] semis (half, one-half).

• SSA 1. special somatic afferent system of dendritic zones of neurons associated with the eye and ear. 2. sulfosalicylic acid.

• SSPE subacute sclerosing panencephalitis.

• SSRI selective serotonin reuptake inhibitor.

• SSS sick sinus syndrome.

• SST serum-separator tube. A type of blood collection tube with no anticoagulant but containing a gel that assists in separating serum from cells; used for biochemistry tests and serology.

• S₁S₂S₃ pattern an electrocardiographic abnormality in which S waves are present in leads I, II, and III. It is associated with right ventricular enlargement.

• stabilate [sta′bľ-lāt] a mixture of blood and tick tissues, expected to contain infective elements of rickettsia or protozoa, in a stable state suitable for storage.

• stabilization [sta″bil-ľ-za′sh n] the process of making firm and steady.

• stable [sta′b l] 1. animal accommodation, usually for horses. 2. to accommodate an animal in a stable as distinct from running at pasture. 3. steady; not easily swayed.

  • s. blackleg caused by the germination of latent spores of Clostridium septicum in tissues. The clinical disease is similar to blackleg.
  • s. cough any of the viral diseases of the upper respiratory tract of horses, but most commonly equine influenza.

• Stabyhoun a rare, medium-sized sporting dog from the Friesland province in the Netherlands. It has a long coat of black, brown, or orange and white. Considered a Dutch national treasure.

• stachybotryotoxicosis [stak″e-bot″re-o-tok″sľ-ko′sis] the disease caused by poisoning by Stachybotrys atra.

• Stachybotrys chartarum (syn. S. alternans, S. atra) [stak″e-bot′ris] a mold in the phylum Ascomycota that grows on stored feed and produces trichothecene mycotoxins. Poisoning is characterized by diarrhea, necrotic ulcers in the mouth, mucosal petechiation, and agranulocytosis. See also satratoxins. Poisoning called alimentary toxic aleucia.

• Stachys arvensis European plant in the family Lamiaceae; contains an unidentified toxin that causes tremor, incoordination, and recumbency if exercised. There is no permanent damage. Called also stagger weed.

• stactometer [stak-tom′ -t r] a device for measuring drops.

• Stader splint [sta′d r] see Stader splint.

• staff [staf] a wooden rod or rod-like structure.

• Staffordshire bull terrier a small (24–38 lb), very muscular, solidly built dog with broad head, moderately short muzzle, half-pricked ears, and medium-length tail. The smooth coat is short and comes in many colors, except black and tan. Smaller than the related American Staffordshire terrier.

• Staffordshire shilling see shilling alopecia.

• stag 1. in abattoir terminology a male animal castrated after it has matured sexually, i.e., more than a year old. Used mostly about cattle beasts or pigs. In rams the age limit is 6 months. In some areas also applied to an unbroken colt more than a year old. 2. to the game hunter an adult male of any of the large deer species.

• stage [stāj] 1. a definite period or distinct phase, as of development of a disease or of an organism. 2. the platform of a microscope on which the slide containing the object to be studied is placed.

• stagger bush Seneciolatifolius, S. retrorsus, Lyonia ligustrina.

• stagger weed see Stachys arvensis.

• staggergrass see Amianthium muscaetoxicum, Melica decumbens.

• staggering disease see Borna disease.

• staggers incoordination of any kind, including a tendency to fall, and recumbency if harassed.

  • blind s. incoordination, aimless wandering as in liver encephalopathy, carbohydrate engorgement. The syndrome called blind staggers of livestock in North America is mostly sulfur-associated polioencephalomalacia, previously erroneously attributed to selenium poisoning.
  • fenugreek s. reported in sheep grazing mature plants or stubble of Trigonella foenum-graecum.
  • flood plain staggers see corynetoxicosis grass s. see lactation tetany (2).
  • paspalum s. see paspalum ergot.
  • annual ryegrass staggers see corynetoxicosis
  • perennial ryegrass s. ruminants and horses grazing pastures dominated by L. perenne (perennial ryegrass) may be affected with a severe incoordination that appears with forced exercise but disappears if the animals are left to their own devices. Caused by tremorgen lolitrems from the endophyte Neotyphodium (Acremonium) lolii that infests the grass.
• staging [stāj′ing] 1. the determination of distinct phases or periods in the course of a disease, the life history of an organism, or any biological process. 2. the classification of neoplasms according to the extent of the tumor.

  • TNM s. staging of tumors according to three basic components: primary tumor (T), regional nodes (N), and metastasis (M). Subscripts are used to denote size and degree of involvement; for example, 0 indicates undetectable, and 1, 2, 3, and 4 a progressive increase in size or involvement. Thus, a tumor may be described as T₁N₂M₀.

• stagnant loop syndrome [stag′n nt] the syndrome of toxemia and dehydration caused by metabolic consequences of stasis of a loop or loops of small intestine. Caused by partial obstruction, paralytic ileus, or radiation injury. The stasis has the effect of encouraging growth of anaerobic bacteria and damage to enterocytes causing diarrhea.

• Staib agar see birdseed agar.

• stain [stān] 1. a substance used to impart color to tissues or cells, to facilitate microscopic study and identification. 2. an area of discoloration of the skin.

  • acid s. a stain in which the coloring agent is in the acid radical.
  • basic s. a stain in which the coloring agent is in the basic radical.
  • carbol fuschin s. used to stain some gram-negative bacteria, including Campylobacter fetus subsp. fetus Castaneda’s s. a technique for demonstrating chlamydial elementary bodies, using formol blue and safranin.
  • Diene’s s. one containing methylene blue, maltose and azure II, used for staining mycoplasma colonies.
  • differential s. one that facilitates differentiation of various elements in a specimen.
  • fluorescein s. one used for many diagnostic purposes, principally the detection of corneal ulceration. See fluorescein.
  • Gram s. used to differentiate gram-positive and gram-negative bacteria based on the difference in the thickness of peptidoglycan in their cell walls. Crystal violet, followed by iodine as a mordant is used to stain bacterial cells, which are then destained with acetone and alcohol, then counterstained with safranin or carbol fuschin.
  • hematoxylin and eosin s. a staining method employed universally for routine histological examination of tissue sections. It is a combination of the basic dye hematoxylin and the alcohol-based eosin. Nuclei stain blue (basophilic) and cytoplasm stain red.
  • India ink s. used to demonstrate capsules on Cryptococcus neoformans and some bacterial species.
  • lambing s. staining of the breech and back of the udder of a ewe caused by the passage of the fetal fluids and then the lochia. Used as a guide to whether or not the ewe has lambed and perhaps lost her lamb.
  • lissamine green s. topically applied dye used for detecting dead or devitalized corneal and conjunctival epithelial cells.
  • Luxol fast blue s. a stain for demonstrating myelin that is stained blue.
  • Macchiavello s. a basic fuscin solution for staining chlamydial elementary bodies.
  • Mallory’s s. stains connective tissue blue.
  • Masson’s trichrome s. connective tissue is stained green or blue, while cytoplasm is red. Useful for demonstrating collagen.
  • metachromatic s. one that produces in certain elements color different from that of the stain itself.
  • methanamine silver s. stains fungal elements in tissue a dark brown.
  • new methylene blue s. a metachromatic dye used for staining blood, vaginal smears, and tissue samples for cytological examination. Particularly useful in demonstrating reticulocytes and Heinz bodies.
  • Newman’s s. used on smears of milk for demonstrating organisms in mastitis.
  • nigrosin s. an aniline dye used in wet mounts to demonstrate capsules, especially with Cryptococcus neoformans.
  • nuclear s. one that selectively stains cell nuclei, generally a basic stain.
  • oil red o s. stains lipids red.
  • periodic acid–Schiff (PAS) s. periodic acid followed by Schiff reagent stains polysaccharides, glycoproteins, and glycolipids. It is used to demonstrate fungal elements.
  • Prussian blue s. see Prussian blue.
  • silver s. a method of demonstrating flagella on bacteria, or for visualizing very thin bacteria, such as leptospires. Also used to stain separated proteins in polyacrylamide gels.
  • Sudan s. see Sudan.
  • supravital s. a stain introduced in living tissue or cells that have been removed from the body.
  • tumor s. an area of increased opacity on a radiograph, due to collection of contrast material in distorted and abnormal vessels, prominent in the capillary and venous phases of arteriography, and presumed to indicate neoplasm.
  • van Gieson s. a stain specific for collagen; often used in combination with Verhoeff stain that identifies elastic fibers.
  • Verhoeff s. a stain specific for elastic fibers.
  • vital s. a stain introduced into the living organism, and taken up selectively by various tissue or cellular elements. Often used to determine the live/dead cell ratio in a cell population.
  • von Kossa s. a silver nitrate stain for phosphates and carbonates that are usually complexed with calcium.
  • Wright’s s. a mixture of eosin and methylene blue, used for demonstrating blood cells.
  • Ziehl–Neelsen s. one of carbol fuchsin, followed by strong acid in alcohol to destain and then a counterstain of methylene blue; used to demonstrate acid-fast organisms, especially Mycobacterium spp., in smears and tissues. A modified method using mild acid to decolorize is used for staining Brucella spp. and Nocardia asteroides. See also acid-fast.

• stainable iron a method of staining a bone marrow smear to determine the amount of body storage of iron.

• staining [stān′ing] 1. artificial coloration of a substance to facilitate examination of tissues, microorganisms or other cells under the microscope. For various techniques, see under stain. 2. marring the appearance.

  • bipolar s. concentration of stain at either end of rod-shaped bacteria; a characteristic of particular species, such as Pasteurella spp.
  • chromosomal s. blood is collected in a highly aseptic manner and placed in tissue culture medium containing a stimulant to cell division. The leukocytes are collected, killed with a cytotoxic agent, enlarged by osmosis in a hypotonic liquid, placed on slides, fixed, and stained.
  • negative s. a procedure visualizing specimens by either light or electron microscopy. In light microscopy, India ink, which blocks the transmission of light is used as a negative stain to detect bacterial capsules. In electron microscopy, electron-dense salts such as sodium phosphotungstate are used in the examination of particles, particularly viruses.
  • radiograph s. may be yellow or brown stains due to inadequate rinsing, or doubly refracting exhibiting different colors depending on angle of viewing.

• stainless steel see steel.

• staircase phenomenon a characteristic of cardiac muscle, the strength of the contraction increases as the interval between contractions increases, up to a point.

• stalagmometer [stal″ g-mom′-t r] an instrument for measuring surface tension by determining the exact number of drops in a given quantity of a liquid.

• stale horseman’s term for the act of urination by a horse.

• stalkage residue of a corn crop after the cobs have been picked by a mechanical harvester. The feed is mature and dry. It may be fed standing or cut and chopped. See also stover.

• stall a small compartment to house one animal, usually a horse, cow, or pig. Calves may also be housed in stalls for reasons of hygiene or in veal fattening units. A stall is usually just large enough for an animal to stand and lie in but insufficient to turn around in; in fact they may be designed specifically so that the animal cannot turn around. There may be a chain across the back, which is always open, or the animal is tied in with a neck chain or a headstall. In open access housing in modern cow barns, no attempt is made to keep the cows in their stalls. See also box (2).

  • s. bed the floor of a stall. Most commonly concrete covered with straw, sawdust or other bedding but earth floors or sand on concrete are probably more comfortable for cows. Pigs manage all right on concrete without bedding.
  • s. fed cattle confined and fed in individual stalls. Contrast with pen-fed or lot-fed.
  • s. kicking a vice in horses that are kept in stalls for too long without exercise.
  • s.-related injury injuries incurred by being restrained in stalls, e.g., teat treads, broken tail.
  • tie s. a method of housing dairy cattle or sows where animals are neck or belly tied in a restricted stall area. Horses are usually cross-tied.

• stall-cramp see inherited periodic spasticity.

• stallion 1. an entire male horse aged 4 years and over. 2. in UK, applied to a male donkey (jack).

  • s. ring see stallion ring.
  • teaser s. stallion used to detect those mares that are in estrus. During the breeding season, those mares to be bred are brought into a crush and the teaser brought alongside. The mares that show estral signs are kept back, usually palpated per rectum to determine the state of their ovaries, and may be bred. The teaser is not used for breeding and is usually a pony or an infertile cryptorchid.
• stance [stans] the posture or position.

  • broad base s. standing with legs far apart; imparts more stability and seen with ataxia or generalized weakness. Called also base-wide and wide-base.

    S-82.

    

    Arched back and painful stance due to mycoplasmal arthritis in a calf.

• stanchion a specially designed headgate to hold an animal in place while allowing feeding and resting. Most commonly used for cattle.

  • s. head locks used between loose housing and feedbunks or feed alley in dairies. Are open while cows feed but are set up so that a throw of a single lever will close the several in a row and catch cows for examination or other procedures.
  • s. housing an older system where cows are tied in for the winter in headlocks of wood or metal and have a confined space in which to lie but feed troughs and water bowls are at the front of the stall and a gutter, nowadays fitted with a mechanical dung remover for the collection of manure and urine.

• stand a standing crop of fodder plants or weeds, e.g., a stand of variegated thistle.

• stand-off in ultrasonography, a device used to increase the distance between the transducer and skin in order to bring the area of investigation into the focal zone.

• standard [stan′d rd] something established as a measure or model to which other similar things should conform.

  • bacteriological s. of meat the standard bacterial count of meat beyond which local legislation forbids the sale or use of meat. The international standard is for <107/g of meat and that Salmonella spp. should not be present in more than one of five 25-g samples, all held at 95°F (35°C) or 68°F (20°C) for chilled meat.
  • s. of care the minimum acceptable treatment for any given disease process.

• Standard Nomenclature of Veterinary Diseases and Operations (SNVDO) an early scheme for veterinary nomenclature based on the American Medical Association’s Standard Nomenclature of Diseases and Operations (SNCO); first published by the AVMA in 1964 with subsequent revisions. Replaced by SNOVET.

• Standard schnauzer see Schnauzer.

• Standardbred a group of breeds of horses used in trotting races. See American Trotter. Called also pacer.

• standardization [stan″d rd-ľ-za′sh n] weighted averaging of a characteristic. It is usually specific to a standard distribution of age or other characteristic.

  • exposure factor s. in radiology is the elimination of variation as much as possible in as many as possible factors that affect the optimum exposure time. Includes using a standard anode-film distance, use of the same processing technique, eliminating surges and drops in input voltage.
• standardized pertaining to data that have been submitted to standardization procedures.

  • s. morbidity rate see morbidity rate.
  • s. mortality rate see mortality rate.

• standstill [stand′stil] cessation of motion, as of the heart (cardiac standstill) or chest (respiratory standstill). Atrial standstill occurs when the atrial myocardium is replaced by fibrotic tissue and fails to conduct normal electrical impulses. English Springer Spaniels are overrepresented for this disease and may develop atrial enlargement and congestive heart failure.

• Stangeria a genus of the family Stangeriaceae of cycads.

• Stanleya pinnata North American selenium indicator plant in the family Brassicaceae; contains large amounts of selenium on soils rich in the element and can cause selenium poisoning characterized by lameness, hoof deformity, alopecia. Called also Prince’s plume.

• stannous [stan′ s] containing tin as a bivalent element.

• stannum (Sn) [L.] tin.

• stanozolol [stan′o-zo-lol″] an androgenic anabolic steroid used in the treatment of weight loss, debility, and nonregenerative anemias.

• Stanton’s disease melioidosis.

• stapedial [sta-pe′de- l] pertaining to the stapes.

• stapediovestibular [sta-pe″de-o-v s-tib′u-l r] pertaining to the stapes and vestibule.

• stapedius relating to the stapes or the stapedius muscle.

  • s. muscle a tiny striated muscle that aids in the dampening of the effects of high-frequency vibrations on the auditory apparatus.

• stapes [sta′pēz] the innermost of the three ossicles of the ear; called also stirrup.

• staphylectomy uvulectomy in humans. In animals the term is used to describe resection of the posterior part of the soft palate.

• staphyline [staf′ -līn] 1. pertaining to the uvula. 2. shaped like a bunch of grapes.

• staphylitis [staf″ -li′tis] inflammation of the uvula or soft palate.

• staphyl(o)- 1. word element. [Gr.] resembling a bunch of grapes, staphylococci. 2. uvula.

• staphylococcal [staf″ -lo-kok′ l] pertaining to Staphylococcus spp.

  • s. clumping test used as a means of measuring the quantity of fibrinogensplit products in a sample of blood.
  • equine s. dermatitis see equine staphylococcal dermatitis.
  • s. food poisoning a disease of humans caused by enterotoxins elaborated by coagulase-positive Staphylococcus aureus of human origin. Dangerous foods for this disease are ham, dried milk, and cold meats generally. Domestic animals appear not to be susceptible to the toxins but the disease is important to veterinarians because animal products, especially milk and chicken meat from animals in their care, may be the origin of this severe, often epidemic, gastroenteritis.
  • s. granuloma persistent, low-grade infection of connective tissue or muscle by Staphylococcus aureus causing the development of granulomas that can become very large, most commonly in the chest of the horse and the mammary gland of the sow. The granuloma is a dense mass of fibrous tissue containing a large number of small abscesses containing thick yellow pus containing granules of club colonies. Called also botryomycosis.
  • s. hypersensitivity see bacterial hypersensitivity.
  • s. mastitis of cows caused by S. aureus may be subclinical, chronic, acute, or peracute with gangrene of the quarter and sometimes death of the cow.
  • s. phage lysate products see staphage lysate.
  • s. protein A a cell-bound protein expressed by most strains of Staphylococcus pseudintermedius recovered from dogs and cats and by Staphylococcus aureus.
  • s. pyemia see tick pyemia.
  • s. septicemia of lambs and less commonly other neonates; high mortality rate; umbilical infection the likely entry portal.

• staphylococcemia [staf″ -lo-kok-se′me-] presence of staphylococci in the blood.

• staphylococcosis [staf″ -lo-kok-o′sis] see enzootic staphylococcosis. Called also tick pyemia.

• Staphylococcus [staf″ -lo-kok′ s] a genus of spherical, gram-positive bacteria tending to occur in grapelike clusters. Members of the family Staphylococcaceae. They are normal flora on the skin and in the upper respiratory tract and are the most common cause of localized suppurating infections. Pathogenic species are characterized by positive reactions in the coagulase test.

  • S. agnetis coagulase variable species associated with subclinical and mild clinical mastitis in cattle.
  • S. aureus a common and important cause of disease in animals including bovine mastitis, tick pyemia (enzootic staphylococcosis), abscesses, dermatitis, furunculosis, meningitis, osteomyelitis, food poisoning, wound suppuration, and bumblefoot in poultry. A significant pathogen of humans and also a common zooanthroponosis, particularly with multiply resistant human strains introduced into surgical wounds in animals. S. aureus subsp. anaerobius causes lesions similar to caseous lymphadenitis in sheep.
  • S. delphini isolated from purulent skin lesions of dolphins
  • S. epidermidis a coagulase negative species that is a common skin and mucosal inhabitant of humans and occasionally animals living in association with humans.
  • S. felis coagulase negative species isolated from lesions in cats.
  • S. hyicus causes exudative epidermitis and occasionally septic arthritis in pigs.
  • S. intermedius the most common staphylococcal species isolated from pigeons. May be confused with S. pseudintermedius.
  • S. pseudintermedius isolated from dogs, cats, horses, and birds, and may be confused with S. intermedius. The most common cause of pyogenic infections in dogs and cats.
  • S. xylosus a rare cause of mastitis in cattle.

• staphylococcus [staf″ -lo-kok′ s] pl. staphylococci [Gr.] any organism of the genus

• coagulase-positive s. see coagulase test.

• staphylodemodicosis demodectic mange complicated by infection with Staphylococcus spp.

• staphyloderma [staf″ -lo-der′m] pyogenic skin infection by staphylococci.

• staphylokinase [staf″ -lo-ki′nās] a bacterial kinase produced by certain strains of staphylococci; it induces fibrinolysis by converting plasminogen to plasmin.

• staphylolysin [staf″ -lol′ -sin] a substance produced by staphylococci that causes hemolysis.

• staphyloma [staf″ -lo′m] protrusion of the sclera or cornea, usually lined with uveal tissue; may be congenital or posttraumatic.

  • anterior s. staphyloma in the anterior part of the eye.
  • corneal s. 1. bulging of the cornea with adherent uveal tissue. 2. one formed by protrusion of the iris through a corneal wound.
  • posterior s. backward bulging of sclera at posterior pole of eye.
  • scleral s. protrusion of the sclera, usually lined with uveal tissue.

• staphyloplasty plastic repair of the soft palate.

• staphyloptosis [staf″ l-op-to′sis] elongation of the soft palate.

• staphylorrhaphy [staf″ -lor′ -fe] surgical correction of a midline cleft in the soft palate.

• staphyloschisis [staf″ -los′kľ-sis] fissure of the soft palate.

• staphylotomy 1. incision of the soft palate. 2. excision of a staphyloma.

• staple a number of wool fibers naturally formed into a cluster about as thick as a human thumb but varying widely in size. Used with reference to fleeces of fine-wool sheep. Similar structures in longwool fleeces are called locks.

  • s. measurements includes staple length, staple strength, staple length variability, and the position of any break in the wool.
  • s. strength force required to break a staple of wool of a given thickness.
• staples [sta′p l] U-shaped stainless steel or Vitallium units with sharp points used for surgical fixation.

  • epiphyseal s. used to staple epiphysis to metaphysis; have metal bracing at the corners. Are driven in to the bone while held in a special holder and are removed with a similar special instrument.
  • soft tissue s. come in a special appliance suitable for animal use. Are expensive but very saving of time. Used especially for skin closure, bowel anastomoses, ligation of pedicle, wherever conventional suturing is very consumptive of time, or difficult because of awkward access.

• stapling [sta′pling] the use of staples as surgical sutures and fixation.

• STAR see Cornell STAR accelerated lambing system.

• StAR [stahr] steroidogenic acute regulatory protein.

• star a color marking in a horse’s coat consisting of a white spot in the center of the forehead; just a few white hairs is sometimes called a flame.

• star grass plants capable of causing cyanide poisoning; most are in the genus Cynodon.

  • gulf s. g. Brachyachneconvergens.

• star of Bethlehem see Ornithogalum.

• starch [stahrch] 1. many glucose units linked together in straight chains by α-glycosidic bonds. Plant starches are referred to as amylopectins while animal starch is called glycogen. Most starches in cooked, and extruded pet foods are easily digested and provide a rapid source of energy. Ingredients such as potatoes, wheat, rice, and corn are rich sources. 2. granular material separated from mature grain of Zea mays (Indian corn, or maize); used as a dusting powder and tablet disintegrant in pharmaceuticals.

  • s. blockers inhibitors of alpha-amylase, used to decrease starch digestion and limit energy intake from starch.
  • s. digestion test a test to assess the ability of the intestine to digest and absorb a polysaccharide. Efficiency measured by the rise in blood glucose after oral administration of starch to an animal that has been fasted.

    S-83.

    

    Carpal radiograph demonstrating transphyseal bridging using a ’staple’.

  • s. equivalent an outmoded way of estimating and expressing the energy value of a feed. Replaced now by metabolizable energy.
  • s. inhalation can occur in pigs in a poorly ventilated environment and when the feed is fed dry. Causes foreign body pneumonia.
  • s.–iodine complex is a deep blue color, and this is used as an indicator of the amount of starch in a solution.
  • resistant s. plant starches that escape enzymatic digestion in the small intestine and are subsequently fermented by colonic bacteria.
  • s. tolerance test see starch digestion test (above).

• staring coat a dry haircoat lacking in luster, usually carrying dandruff or scurf. May be caused by poor cutaneous circulation and lack of sebaceous secretion resulting from a general state of ill health such as in any toxemia.

• Starlicide 3-chloro-p-toluidine hydrochloride, highly toxic to starlings, blackbirds, and gulls but much less toxic to most other birds, mammals, and avian predators. Used as a 1% addition to poultry pellets to reduce starling populations on livestock feeding operations and reduce their consumption of feed rations.

• Starling curves [stahr′ling] graphic curves that relate cardiac function to venous inflow. Called also cardiac function curve. See also Frank–Starling mechanism.

• Starling’s hypothesis, law [stahr′ling] the law relating to the passage of fluid out of a capillary depending on the hydrostatic and osmotic pressures of the blood and the same pressures of tissue fluid, the net effect of the opposing pressures determining the direction and rate of flow.

• starry-sky effect the cytological effect created in a histological slide of a lymphoma by the presence of a large number of tingible-body macrophages, usually associated with a high rate of apoptosis.

• stars of Winslow red or dark dots and lines in the tapetal area of the ocular fundus in many species, especially cats and large herbivores. Represent the end-on view of prominent choroidal capillaries as they emerge through the tapetum to nourish the outer retina.

• starter [stahr′t r] Welsh springer spaniel.

• startle reaction [stahr′tl] the mental state of suddenly aroused awareness; manifested by a flight or fight or submit pattern of behavior and posture.

• starvation [stahr-va′sh n] long-continued deprival of food and its morbid effects. Hunger, loss of body weight, and decreased muscle power and endurance occur early. Late stages include signs of milk yield drop, cessation of defecation and drinking, emaciation, loss of skin turgor without dehydration, weakness, slow heart rate, and hypothermia.

  • preoperative s. see preoperative fasting.

• starve–feed cycle metabolic response to feeding usually involving an increased sensitivity to glucose resulting in markedly increased rates of insulin secretion after varying periods of starvation, such as an overnight fast in humans or a prolonged fast, or during winter in hibernating animals.

• stasis [sta′sis] a stoppage or diminution of flow, as of blood or other body fluid, or of intestinal contents.

  • gastric s. reduced motility, without primary organic disease, leading to retention of gastric contents. Can be caused by stress, trauma, ulcers, peritonitis, and gastritis.
  • urine s. can be caused by abnormalities in structure or innervation of the urinary outflow tract that result in incomplete emptying of the bladder or pooling of urine in diverticula. Important in the etiology of cystitis.

• -stasis word element. [Gr.] maintenance of (or maintaining) a constant level; preventing increase or multiplication.

• stat. [L.] statim at once

• state [stāt] condition or situation.

  • excited s. the condition of a nucleus, atom or molecule produced by the addition of energy to the system as the result of absorption of photons or of inelastic collisions with other particles or systems.
  • ground s. the condition of lowest energy of a nucleus, atom, or molecule.
  • refractory s. a condition of subnormal excitability of muscle and nerve following excitation.
  • resting s. the physiological condition achieved by complete rest for at least 1 hour.
  • steady s. dynamic equilibrium.
• static [stat′ik] 1. stable with opposing forces in balance. 2. minor electric disturbance.

  • s. fetal cadaver see mummification.
  • s. reaction reflexes that maintain a steady posture; they may be local, segmental or general.

• statim [sta′tim] [L.] at once; immediately; abbreviated stat.

• station [sta′sh n] 1. position; stance. 2. see ranch.

• statistic [st -tis′tik] a numerical value calculated from a number of observations in order to summarize them.

  • order s. see rank.
• statistical pertaining to or emanating from statistics.

  • s. efficiency between-test comparisons are based on the ratio of sample sizes required for the tests to have equal probabilities of detecting the same false null hypothesis; the more efficient test will have the smaller sample size.
  • s. methods procedures for collecting, classifying, summarizing, analysing, and making conclusions about, data. See also regression (4), path analysis, factor, discriminant analysis.
  • s. significance see significance.

• staphylococcin [staf″ -lo-kok′sin] see bacteriocin (1).

• statistics [st -tis′tiks] 1. numerical facts pertaining to a particular subject or body of objects. 2. the science dealing with the collection, tabulation, and analysis of numerical facts.

  • inferential s. conclusions, usually quantitative, drawn from an analysis of data.
  • salvage s. statistical technique used in an attempt to derive some useful information from a poorly designed or poorly executed experiment.
  • vital s. see vital statistics.

• statoacoustic [stat″o- - ′tik] pertaining to balance and hearing.

• statoconia [stat″o-ko′ne- ] [Gr.] plural of statoconium; minute calcareous particles in the gelatinous membrane surmounting the macula in the inner ear. Called also otoconia.

• statoconial membrane part of each otolithic organ; the hair cells in the organ carry stereocilia that project from the hairs and into the statoconial membrane that is covered with otoliths.

• statolith [stat′o-lith] 1. a granule of the statoconia. 2. see otolith.

• STATssignal transducers and activators of transcription; a class of transcription factors that are activated in the cytosol following ligand binding to cytokine receptors.

• stature [stach′oor] the height of an animal in the standing position.

• status [sta′t s] [L.] condition, state.

  • s. asthmaticus asthmatic crisis; a sudden, intense, and continuous generalized bronchoconstriction with dyspnea, gagging, and cyanosis. May be seen in feline bronchial disease.
  • s. epilepticus rapid succession of epileptic spasms without intervals of consciousness; brain damage may result.
  • s. spongiosis see spongiosis, spongy degeneration.

• stay apparatus [sta] the anatomical mechanism in both the fore- and hindlimbs of horses that enable the animal to stand with little or no muscular effort. Efficiency of the apparatus is based on the judicious location of fibrous tissue. Many muscles, ligaments, and tendons participate, especially the suspensory ligament, the flexor tendons, and their check (or accessory) ligaments, and in the hindlimb, the peroneus tertius and the patellar-locking mechanism.

• stayer a horse that can gallop at racing speed for at least 1.5 miles (2.4 km).

• St. Bernard a very large (110–200 lb) dog with massive, broad head, medium-sized ears lying close to the head, and a long tail. There are two varieties, the most familiar (rough) has a long, thick coat, while the (earlier) smooth variety has a shorter coat, lying close to the body. The breed is predisposed to osteogenic sarcoma, ectropion, entropion, hip dysplasia, osteochondrosis, haemophilia, and congestive cardiomyopathy.

• steady-state level said of a medication regimen that maintains relatively constant therapeutic plasma or tissue fluid concentrations of the drug; a plateau.

  S-84.

  

  St. Bernard (shorthaired).

• steam the vapor created by heating water to 212°F (100°C).

  • s. sterilization see sterilization (2).

• steapsin the fat-splitting enzyme (lipase) of the pancreatic juice. Now more usually called pancreatic lipase.

• steapsinogen the precursor of steapsin.

• stearate [ste′ -rāt] any compound of stearic acid.

• stearic acid [ste-ar′ik] an 18-carbon saturated fatty acid from animal and vegetable fats.

• stearin [ste′ -rin] glycerol tristearate, a substance common in mammalian fat. Formed from the reaction of stearic acid with glycerol. See also olein, palmitin.

• stear(o)- word element. [Gr.] fat.

• steatitis [ste″ -ti′tis] inflammation of fatty tissue. See also yellow fat disease.

• steat(o)- word element. [Gr.] fat, oil.

• steatocystoma [ste″ -to-sis-to′m] a human term for a sebaceous cyst.

• steatogenous [ste″ -toj′-n s] producing fat; lipogenic.

• steatolysis [ste″ -tol′ľ-sis] the emulsification of fats preparatory to absorption.

• steatoma [ste″ -to′m] pl. steatomata, steatomas. 1. lipoma. 2. sebaceous cyst filled with lipid material.

• steatomatosis [ste″ -to-m -to′sis] the presence of numerous sebaceous cysts.

• steatonecrosis [ste″ -to-n -kro′sis] fat necrosis.

• steatopathy disease of the sebaceous glands.

• steatopygia [ste″ -to-pij′e-] excessive fatness of the buttocks; a normal state in fat-tailed sheep.

• steatorrhea [ste″ -to-re′] excess fat in the feces due to a malabsorption syndrome caused by disease of the intestinal mucosa or pancreatic enzyme deficiency. The feces are bulky, greasy, malodorous, and pale in color.

  • pancreatic s. see exocrine pancreatic insufficiency.
• steatosis [ste″ -to′sis] fatty degeneration.

  • muscular s. excess fat deposits in muscle; a problem only at meat hygiene inspection and grading.

• STEC shiga toxin-producing Escherichia coli.

• steed see nag.

• steeplechase a horse race conducted over fences, open ditches, and water jumps.

• steeplechaser a horse schooled in and used for steeplechase racing.

• steer castrated male cattle beast over a year of age. See also bullock, buller steer.

  • s. bulling see bulling.

• steg stag.

• stegnosis [steg-no′sis] constriction; stenosis.

• Stegomyia fasciata [steg″o-mi′y ] a mosquito vector of the virus of fowl pox.

• Steinmann name given to specific designs of orthopedic hardware.

  • S. extension extension exerted on the distal fragment of a fractured bone by means of a nail or pin (Steinmann pin) driven into the fragment. Called also nail extension.
  • S. pin intramedullary pin with a choice of ends, either screw, chisel, or trocar. Can be plain at one end or have one of the selected points at each end. Pin drills to drill the holes for the pins, and a chuck to grasp the end of the pin and drive or rotate it are available.

• stell circular stone or metal corral providing shelter for sheep in windswept, snow-susceptible areas. Has lean-to, inward-facing roof around the wall.

• stella [stel′ ] pl. stellae [L.] star.

• Stellaria media the widespread weed called chickweed, member of the family Caryophyllaceae, which may cause nitrate–nitrite poisoning.

• stellate [stel′āt] star-shaped; arranged in rosettes.

  • s. ganglion cervicothoracic and middle cervical ganglion.
  • s. reticulum center of the enamel organ of the embryonic tooth.
• stem cell [stem] unspecialized cells that have the potential to develop into many different cell types and retain the ability to divide throughout life. They can be induced to become highly specialized organ-specific cells. There are two main types: embryonic stem cells and adult stem cells. Also see stem cell.

  • candidate s.c. a stem cell in the hemopoietic system whose function is only assumed.
  • s.c. therapy the use of stem cells to treat or prevent a disease or a condition. The potential for use in veterinary medicine is the subject of many studies. It has been used clinically, particularly in the treatment of osteoarthritis and spinal injury in dogs, and tendon and ligament injuries in horses.

• stem line-template a process of development of new muscle fibers, evident in the fetal and newborn pig and important in the development of splayleg in that species. A centrally located muscle fiber in a sublobule of muscle divides longitudinally or acts as a template for myoblasts to form a new fiber. The process is repeated until a whole new sublobule is formed.

• Stemodia Australian plant genus in the Scrophulariaceae family; contain cucurbitane triterpene steroid glycosides causing diarrhea, cardiac arrhythmia, and polyuria. Includes S. florulenta (Morgan flower), S. kingii.

• sten(o)- word element. [Gr.] narrow, contracted, constriction.

• Stenocarpella maydis a toxic mold in the phylum Ascomycota that grows on corn grain; causes incoordination and paresis in cattle in southern Africa and South America that are pastured on crops carrying infected cobs. Produces the mycotoxins diploidiatoxin, chaetoglobosins K, L, M, and O, diplosporin, and diplonine. Formerly called Diplodia maydis.

• stenochoria [sten″o-kor′e- ] stenosis.

• stenocoriasis [sten″o-k -ri′ -sis] constriction of the pupil; more commonly termed miosis.

• stenohaline species of fish capable of osmoregulation only in a narrow range of salinities; the opposite of euryhaline.

• stenopeic [sten″o-pe′ik] having a narrow opening or slit.

• stenosed [st -nōzd′] narrowed; constricted.

• stenosis [st -no′sis] narrowing or contraction of a body passage or opening. See also specific anatomical sites.

  • aortic s. see aortic stenosis.
  • esophageal s. a common cause of esophageal obstruction, caused commonly by esophageal trauma, caused by foreign bodies or swallowing caustic or irritating substances, or severe esophagitis, as occurs in reflux under anesthesia; congenital stenosis is often associated with tracheoesophageal fistula.
  • left atrioventricular s. see mitral stenosis (below), valvular stenosis.
  • mesonephric duct s. occurs as stenosis of the ductus deferens or epididymis; may be associated with renal aplasia.
  • mitral s. a narrowing of the left atrioventricular orifice, causing signs of exercise intolerance, syncope, and ultimately congestive heart failure. Occurs in association with mitral valve dysplasia in Newfoundlands and Bull terriers.
  • nasopharyngeal s. an acquired disorder in cats, usually following chronic upper respiratory infection, which causes upper airway obstruction with mucopurulent nasal discharge and a wheezing respiration, which is relieved with open mouth breathing.
  • paramesonephric duct s. focal defects in the duct lead to segmental aplasia or stenosis of the uterine tube or horn.
  • pulmonary artery s. the most common cardiac defect in dogs; it is a narrowing of the pulmonary outflow tract and may occur in any one of a number of common sites including infundibular, valvular, and subvalvular.
  • rectovaginal s. see rectovaginal constriction.
  • right atrioventricular s. see tricuspid stenosis (below).
  • subepiglottic s. has the effect of reducing air flow into and out of the lungs.
  • tricuspid s. narrowing or stricture of the tricuspid orifice of the heart. An uncommon congenital defect; accompanies tricuspid dysplasia, a heritable condition in Labrador retrievers.
  • valvular s. see aortic, pulmonary, atrioventricular.

• stenostomia narrowing of the mouth.

• stenothermal, stenothermic [sten″o-ther′m l] pertaining to or characterized by tolerance of only a narrow range of temperature.

• stenothorax [sten″o-thor′aks] abnormal narrowness of the chest.

• stenotic [st -not′ik] marked by abnormal narrowing or constriction.

• Stenson’s duct duct of the parotid salivary gland.

• stent [stent] a mold for keeping a skin graft in place, made of Stent’s mass or some acrylic or dental compound; by extension, a device or mold of a suitable material used to hold a skin graft in place or to provide support for tubular structures that are being anastomosed. Also used in vascular and bile duct surgery, and repair of laryngeal, tracheal, nasal trauma, and stenosis.

• step cycle [step] the sum of the movements made during locomotion by a limb from the time it leaves the ground until it leaves the ground on the next occasion.

• step mouth [step] a rectangular type of overgrowth of individual cheek teeth; particularly in equines, lagomorphs, and rodents.

  S-85.

  

  Step mouth in a teenaged pony.

• Stephania japonica plant member of the family Menispermaceae; contains an unidentified toxin that causes incoordination, recumbency, convulsions, paralysis. Called also S. hernandifolia.

• Stephanofilaria [stef″ -no-fľ-lar′e-] a genus of nematodes in the family Filariidae; cause chronic dermatitis. See also stephanofilariosis.

  • S. assamensis causes chronic dermatitis in buffaloes, goats, and cattle. In cattle the disease is called humpsore.
  • S. dedoesi found in the skin of cattle.
  • S. dinniki causes dermatitis in the black rhinoceros.
  • S. kaeli found on the legs of cattle.
  • S. okinawaensis causes dermatitis of the muzzle and teats of cattle.
  • S. stilesi causes dermatitis on the ventral abdominal wall of cattle.
  • S. zaheeri found on the inner side of the ear pinna of buffaloes.

• stephanofilariasis [stef″ -no-fil″-ri′ -sis] see stephanofilarosis.

• stephanofilarosis [stef″ -no-fil″ -ro′sis] infection with filariid worms of the genus Stephanofilaria

  • cutaneous s.Stephanofilaria dedoesi causes dermatitis in cattle (cascado). S. kaeli and S. assamensis cause dermatitis in cattle (humpsore), S. zaheeri causes contagious otorrhea (earsore), a dermatitis around the ear in buffalo, S. stilesi and S. okinawaensis also cause dermatitis along the ventral midline in cattle. Similar infestations include Parafilaria multipapillosa that causes subcutaneous nodules in horses, P. bovicola causes similar lesions in cattle, Suifilaria suis does the same in pigs. The dermatitis is manifested by small papules that enlarge to form itchy, scabby lesions that suffer much rubbing. The lesions occur at various sites on the body depending on the species of worm. See Parafilaria , Stephanofilaria.

• Stephanorossia palustris Oenanthepalustris.

  S-86.

  

  Stephanophilarosis (’humpsore’) in a cow.

• Stephanostomum a genus of intestinal flukes in the family Acanthocolpidae.

  • S. baccatum found in the intestines of marine fish but thought to be not pathogenic.
  • S. casum found in blue and gold snappers.

• stephanuriasis the disease of pigs caused by the kidney worm Stephanurus dentatus. Characterized by poor feed utilization and growth, and later emaciation, paralysis, and ascites.

• Stephanurus [stef″ -nu′r s] the only genus of clinical importance in the nematode family Stephanuridae.

  • S. dentatus found in the kidneys of pigs and rarely as aberrant parasites in cattle and horses. It may also be found in the liver, pancreas, and other organs of pigs.

• Steppe several Russian breeds of cattle, e.g., Red Steppe, Grey Steppe.

• stepwedge a block of aluminum shaped like a series of steps. Used to test the characteristics of the x-ray beam, film, filters, and to standardize exposure factors.

• stepwise incremental; additional information is added at each step.

  • s. multiple regression used when a large number of possible explanatory variables are available, and there is difficulty interpreting the partial regression coefficients. s. prospective trial see prospective trial.

• sterc(o)- word element. [L.] relationship to feces.

• stercobilin [stur″ko-bi′lin] a bile pigment derivative formed by air oxidation of stercobilinogen, an end product of heme metabolism; it is a brown-orange-red pigmentation contributing to the color of feces and also urine, where it is called urobilin.

• stercobilinogen [stur″ko-bi-lin′o-j n] a bilirubin metabolite and precursor of stercobilin. Small amounts, termed urobilinogen, are found in the urine.

• stercoracic involving posterior station development in trypanosomes, that is infective stages are passed in the feces of the insect host.

• Stercoraria the posterior station group of trypanosomes transmitted by contamination through the feces of the insect vector. Includes Trypanosoma cruzi, T. lewisi, T. melophagium, T. nabiasi, T. rangeli, T. theileri, T. theodori.

• stercorarian, stercoral, stercoraceous, stercoracic [stur″k -rar′e- n] of fecal origin; said of trypanosomes (e.g., T. cruzi) passed to the mammalian host in the feces of the reduviid bugs. See also Stercoraria.

• stercorolith fecalith; an intestinal concretion formed around a center of fecal matter.

• stercoroma [stur″k -ro′m] a tumor-like mass of fecal matter in the rectum; fecaloma.

• stercus [L.] dung, feces.

• stereo- word element. [Gr.] solid, firm, three-dimensional.

• stereoarthrolysis [ster″e-o-ahr-throl′ľ-sis] surgical loosening of a joint or formation of a movable new joint in cases of bony ankylosis.

• stereoauscultation [ster″e-o-aws″k l-ta′sh n] auscultation with two stethoscopes, on different parts of the chest.

• stereochemistry [ster″e-o-kem′is-tre] the branch of chemistry dealing with the space relations of atoms in molecules.

• stereocilium [ster″e-o- sil′e- m] nonmotile, branched, long cellular processes of the nature of long microvilli.

• stereocinefluorography [ster″e-o-sin″ -fl$\stackrel{⌣}{o}$ $\stackrel{⌣}{o}$-rog′r -fe] recording by motion picture camera of images observed by stereoscopic fluoroscopy, affording three-dimensional visualization. No longer in common use.

• stereoencephalotomy [ster″e-o- n-sef″-lot′ -me] stereotaxic surgery.

• stereoisomer [ster″e-o-i′so-m r] see isomer.

• stereoisomerism [ster″e-o-i-som′ r-iz- m] isomerism in which the compounds have the same structural formulae, but the atoms are distributed differently in space.

• stereoradiography, stereoroentenography [ster″e-o-ra″de-og′r -fe] paired radiographs of a part, taken from slightly different angles, and viewed with a stereoscopic device, giving a three-dimensional effect. No longer in common use.

• stereoscope [ster′e-o-skōp″] an instrument for producing the appearance of solidity and relief by combining the images of two similar pictures of an object.

• stereoscopic [ster″e-o-skop′ik] three-dimensional; having depth, as well as height and width.

  • s. microscope see stereoscopic microscope.

• stereospecific [ster″e-o-sp -sif′ik] specificity for one stereoisomer of a particular enzyme substrate or reactant in a chemical reaction.

• stereotactic [ster″e-o-tak′tik] stereotaxic.

• stereotaxic [ster″e-o-tak′sik] 1. pertaining to or characterized by precise positioning in space; said especially of discrete areas of the brain that control specific functions. 2. pertaining to or exhibiting stereotaxis.

  • s. surgery the production of sharply localized lesions in the brain after precise localization of the target tissue by use of three-dimensional coordinates.

• stereotaxis [ster″e-o-tak′sis] movement or growth in response to contact with a solid or rigid surface.

• stereotropism [ster″e-ot′r -piz- m] stereotaxis.

• stereotypy [ster′e-o-ti″pe] persistent repetition of a movement, act, for no obvious purpose, a form of obsessive-compulsive behavior.

• steric [ste′rik] pertaining to the spatial arrangement of atoms.

• sterigmatocystin [st -rig″m -to-sis′tin] a polyketide mycotoxin produced by Aspergillus nidulans and A. versicolor. A biosynthetic precusor of aflatoxin. In monkeys and rats causes nephritis and hepatitis and is hepatocarcinogenic in rats.

• sterilant [ster′ľ-l nt] a sterilizing agent, i.e., an agent that destroys microorganisms.

• sterile [ster′il] 1. not fertile; barren; not producing young. See also fertility. 2. aseptic; not producing microorganisms; free from living microorganisms.

  • s. field the area defined by the instrument table containing sterile instruments placed over, or immediately adjacent to, the surgery table, the draped patient and the front of the gown worn by the surgery team from chest to table level and the sleeves from above the elbow to the cuff.
  • s. insect release method a method of insect control of particular use in insects in which mating occurs only once, e.g., screw-worm fly; artificially bred flies are sterilized by irradiation and released; if sufficient sterile male flies are released most of the wild female flies will mate with a sterile fly, and the population is sufficiently diminished to lead to a control situation. Called also SIRM.
  • s. pack see sterile surgical pack.
• sterility [st -ril′ľ-te] the state of being sterile. See also infertility.

  • cryptorchidism s. see cryptorchidism.
  • hybrids s. offspring of parents of different species, these animals are usually sterile due to differences between the chromosomes of the two parents.
  • intersex s. sterility due to chromosomal differences within the patient.
  • nondisjunction s. sterility due to chromosomal errors.
  • polled goats s. a small percentage of all genetically female polled goats are sterile due to masculinization.
  • XX male dogs s. a Y chromosome-dependent character is an obligatory primary component in transforming the indifferent gonad into a testis.
• sterilization [ster″ľ-lľ-za′sh n] 1. the process of rendering an animal incapable of reproduction, by castration, vasectomy, ovariohysterectomy, or other procedure. 2. the process of destroying all viable microorganisms. It is accomplished by heat (wet steam under pressure at 121°C for at least 20 minutes, or dry heat at 160–180°C for 3 hours), gamma irradiation, or bactericidal chemical compounds, such as ethylene oxide.

  • skin s. not a practical possibility, but a marked temporary reduction in the bacterial population of the skin, as in presurgical preparation of the surgical site and the hands of operating personnel, is achieved with thorough scrubbing, soaking, or repeated applications of antiseptics.

• sterilize [ster′ľ-līz] to subject to sterilization.

• sterilizer [ster′ľ-līz″ r] apparatus used to rid instruments, dressings, etc., of all viable microorganisms. See also autoclave.

• Stern anthrax vaccine avirulent spore vaccine producing 2-year immunity with no risk of causing the disease.

• sternal [ster′n l] pertaining to the sternum.

  • s. puncture insertion of a hollow needle into the sternum for the purpose of obtaining a sample of bone marrow. Most often used in horses.
  • s. recumbency the animal lies down on its ventral thoracic and abdominal walls, usually with the legs tucked underneath the body; the sagittal plane is vertical, and the head is in a vertical plane. Called also ventral recumbency.

• Sternberg’s giant cells [sht rn′b rg] see Reed–Sternberg cell.

• Sternberg–Reed cell [sht rn′b rg rēd′] see Reed–Sternberg cell.

• sternebra [stur′n -br] pl. sternebrae one of the bony segments of the sternum.

• stern(o)- word element. [L., Gr.] relationship to the sternum.

• sternocephalic muscle see Table 12.1H.

• sternocostal [stur″no-kos′t l] pertaining to the sternum and ribs.

• sternodymia union of two fetuses by the anterior chest wall.

• sternodymus [st r-nod′ľ-m s] conjoined twins united at the anterior chest wall.

• sternohyoid [stur″no-hi′oid] pertaining to the sternum and hyoid bone.

• sternoid [stur′noid] resembling the sternum.

• sternomastoid [stur″no-mas′toid] pertaining to the sternum and the mastoid process of the temporal bone.

• sternopericardial [stur″no-per″ľ-kahr′de- l] pertaining to the sternum and pericardium.

• sternoschisis [st r-nos′kľ-sis] congenital fissure of the sternum.

• Sternostoma [stur″no-sto′m ] a genus of mites of the family Rhinonyssidae. Found in the trachea of birds; they cause respiratory difficulty in companion birds.

• Sternostomum tracheacolum a tracheal mite in free-living and captive finches and canaries. The correct name is Sternostoma tracheacolum.

• sternothyroid [stur″no-thi′roid] pertaining to the sternum and thyroid cartilage or gland.

• sternotomy [st r-not′ -me] incision of the sternum as an approach for a thoracotomy. The incision may be median, through the midline, or transverse, most commonly as an extension of an intercostal thoracotomy incision, across the sternum, and up the other side.

• sternum [stur′n m] the breastbone, a median segmented skeletal structure made up of several elements or sternebrae, often with a considerable portion remaining cartilaginous into adulthood. It articulates with the cartilages of the sternal ribs and clavicles when large. It has three parts, the manubrium, the body, and the xiphoid process, and consists of vascular, spongy bone covered with a thin layer of compact bone. In ruminants it has a flat ventral surface, while in horses it bears a keel (carina). It is especially well developed, as a nonsegmented keeled bone, in flying birds.

  • inherited short s. in the North Country Cheviot breed; characterized by a heavy mortality in newborn lambs resulting from rupture of the liver; the latter thought to occur because of the exposed position of the liver as a result of the absence of the sternum.
  • point of the s. the most cranial point of the sternum (the apex of the manubrium).

• sternutatory [st r-nu′t -tor″e] 1. causing sneezing. 2. an agent that causes sneezing.

• stereocampimeter [ster″e-o-kam-pim′ -t r] an instrument for studying unilateral central scotomas and central retinal defects in humans.

• steroid [ster′oid] a complex molecule containing carbon atoms in four interlocking rings forming a hydrogenated cyclopentophenanthrene ring system; three of the rings contain six carbon atoms each and the fourth contains five. Found only in eukaryotes. Steroid derivatives are important in body chemistry. Among them are the male and female sex hormones, such as testosterone and estrogen, and the hormones of the cortices of the adrenal glands, including cortisone. Vitamins of the D group are steroids involved in calcium metabolism. The cardiac glycosides, a group of compounds derived from certain plants, are partly steroids. Sterols, including cholesterol, are steroids. Cholesterol is the main building block of steroid hormones in the body; it is also converted into bile salts by the liver.

  • s. I alfaxalone. see alfaxalone.
  • s. II alfadolone. see alfadolone.
  • s. diabetes see steroid diabetes mellitus.
  • s. hormones see androgenic steroids, corticosteroid, glucocorticoid, mineralocorticoid, anabolic steroid.

• steroid-responsive meningitis-arteritis (SRMA) [ster′oid] see steroid-responsive meningitis-arteritis.

• steroidal emanating from or pertaining to steroid.

  • s. saponins see lithogenic saponins.
  • s. glycoalkaloids toxins including solanidine, soladulcidine, solasidine, tomatidine found in solanaceous plants.

• steroidogenesis [st -roi″do-jen′ -sis] production of steroids, as by the adrenal glands.

• steroidogenic acute regulatory protein (StAR) [st -roi′do-jen′ik] transport protein involved in the transport of cholesterol within the mitochondrion; has a regulatory role in steroid hormone production.

• sterol [ster′ol] any steroid, e.g., cholesterol and ergosterol, having long (8–10 carbons) aliphatic side-chains at position 17 and at least one alcoholic hydroxyl group; the sterols have lipid-like solubility.

• stertor [stur′tor] snoring; sonorous respiration, usually due to partial obstruction of the upper airway. May be possible by careful auscultation to determine the site of the stertor, e.g., laryngeal stenosis, pharyngeal obstruction, nasal obstruction.

• steth(o)- word element. [Gr.] chest.

• stethoscope [steth′o-skōp] an instrument used to hear and amplify the sounds produced by the heart, lungs, and other internal organs. The modern stethoscope is binaural, with two earpieces and flexible rubber leading to them from the two-branched opening of the bell or cone. In this way, sound travels simultaneously through both of the branches to the earpieces. See also phonendoscope.

  • electronic s. audible sounds are magnified through an amplifier to earphones, of which there may be more than one set, and may be broadcast through loudspeakers, but in both instances the results are mediocre.
  • esophageal s. one passed into the esophagus with the tip positioned at the level of the heart. It provides an excellent means of monitoring heart sounds and respiration while the animal is anesthetized.
• stethoscopy [steth-os′k -pe] examination using a stethoscope

  • tracheal s. detects respiratory sounds in the upper respiratory tract.

• stethospasm [steth′o-spaz″ m] spasm of the chest muscles.

• Stevens power law attempts to quantitate sensory inputs; the law holds that the perceived intensity of the sensation equals the actual intensity of the stimulus raised to a specified power, the value of the power varying with the type of receptor.

• Stevens scissors see tenotomy scissors.

• stewardship the occupation of being a steward or custodian. Referring to animals it implies the caring sort of relationship based on an acceptance of the need to include the rights of animals in overall plans to maintain financial viability.

• Stewart’s Range syndrome corynetoxicosis of sheep in south-eastern South Australia associated with Rathayibacter toxicus in the nematodeinduced seedhead galls on Polypogon monspeliensis.

• Stewart’s method a concept of assessing clinical acid-base disturbances based on a physicochemical approach to the determinants of the dissociation of water by using strong ion difference. See also Henderson–Hasselbalch equation and strong ion gap.

• STH somatotropic (growth) hormone.

• sthenic [sthen′ik] active; strong; excessive or vigorous activity.

• stibialism [stib′e- l-iz- m] antimony poisoning.

• stibium (Sb) [L.] antimony; the old name for the element antimony.

• stibogluconate sodium a pentavalent antimonial with antiprotozoal activity used in the treatment of leishmaniasis in dogs.

• stibophen [stib′o-f n] a sodium antimony compound used at one time as a treatment for heartworm in dogs but now discarded because of toxicity.

• stichochrome any neuron having the stainable substance arranged in more or less regular layers.

• Sticker’s sarcoma [shtik′ rs sahr-ko′m] see canine transmissible venereal tumor.

• sticking the abattoir technique of bleeding the animal out at slaughter. There are many techniques used including those used in ritual slaughter. The traditional methods are the slash across the throat cutting arteries, veins, trachea and esophagus, and even the spinal cord, and the stab method with the knife being thrust into the jugular vein at the base of the neck. The latter is used in cattle and pigs, the former in sheep. See also Jewish slaughter, Muslim slaughter.

  • over s. see back bleeding.
  • prone s. a method of slaughtering pigs in which the pigs are stunned, then conveyed in a prone position on a conveyor belt past the various stations including the sticking or jugular opening station.

• stickleback fish belonging to the family Gasterosteidae.

• sticky ends the ends of a staggered cut made by a restriction endonuclease in which the terminal portion of the DNA has an overhang of unpaired nucleotides. see cohesive end.

• stiff lamb disease see enzootic muscular dystrophy.

• stiff lung decreased lung compliance.

• stiff sickness ephemeral fever.

• stiffness [stif′nis] half way to rigidity, tetany; result of insufficient use of the part.

• stiffs one of the very large number of colloquial names given to the disease of cattle caused by a nutritional deficiency of phosphorus. See also osteomalacia.

• stifle [sti′f l] the homolog of the human knee in the quadruped, made up of the femorotibial and femoropatellar joints. Disease conditions include degenerative arthritis, dislocation of the patella, rupture of the cruciate ligaments, or injury to the cartilaginous menisci.

  • locking s. see patellar luxation.

• stigma [stig′m ] pl. stigmas, stigmata [Gr.] any physical mark or peculiarity that aids in identification or diagnosis of a condition.

  S-87.

  

  Stifle joint of the dog.

  • follicular s. a 2-mm-wide band around the meridian of all follicles greater than 4-mm diameter in the left ovary of the domestic fowl.

• stigmatization [stig″m -tľ-za′sh n] the formation of stigmas.

• stilbamidine see hydroxystilbamidine isethionate.

• stilbestrol [stil-bes′trol] a synthetic estrogen used in the treatment of female animals for infertility and bitches for urinary incontinence. Its use as a growth promotant, especially in cattle, has been discontinued because of fears that it is a carcinogen. Its use is also not without toxicity hazards. Overfeeding of stilbestrol as a growth promotant causes poisoning characterized by relaxation of pelvic ligaments, elevation of the tailhead, susceptibility to pelvic fracture and hip dislocation, and prolapse of rectum and vagina. In castrated males, there is a tendency for obstructive urolithiasis to occur. Pigs also show anuria, kidney enlargement, and thickening of the ureters. See also diethylstilbestrol, estrogen.

• Stilesia [sti-le′zh ] a genus of tapeworms in the family Thyanosomatidae.

  • S. globipunctata found in the small intestine of ruminants and causes sufficient injury to kill some animals.
  • S. hepatica found in the bile ducts in all ruminant species and causes thickening of the duct walls, but there is no clinical disease.

• stilet [sti-let′] stylet.

• Still–Luer rongeur [stil-loo′ r raw-zhur′] double-action, scissor type instrument with spoon-shaped, sharp-edged blades facing each other. The blades in different individual instruments are bent at different angles from the line of cutting so that inaccessible sites can be reached with the appropriate instrument.

• stillbirth [stil′birth] delivery of a fully formed dead neonate.

• stillborn [stil′born] born dead.

• Stille shears plaster shears with a powerful double action with angled blades that allow cutting while the handles are well away from the patient.

• Stillingia an American plant genus in the family Euphorbiaceae; includes S. dendata, S. treculeana. It contains cyanogenetic glucosides and may cause poisoning. Called also Queen’s delight.

• stimulant [stim′u-l nt] 1. producing stimulation. 2. an agent that stimulates.

• stimulate [stim′u-lāt] to excite functional activity in a part.

• stimulation [stim″u-la′sh n] the act or process of stimulating; the condition of being stimulated.

  • double burst s. a technique of nerve stimulation in which two short tetanic stimuli are applied and the response pattern used to monitor neuromuscular blockade during anesthesia.
  • s. index the ratio of the number of proliferating T lymphocytes present in lymphocyte cultures exposed to antigen or mitogen to the number of T lymphocytes in parallel cultures unexposed to antigen or mitogen. It is determined by adding tritiated thymidine to the culture usually 3–5 days after stimulation. The radiolabel is incorporated into DNA of those cells that are stimulated to divide.
• stimulus [stim′u-l s] pl. stimuli [L.] any agent, act, or influence that produces functional or trophic reaction in a receptor or an irritable tissue.

  • appetitive s. pleasure-eliciting stimulus.
  • aversive s. involves fear or pain-eliciting stimuli and is the opposite of appetitive stimulation.
  • conditioned s. a neutral object or event that is psychologically related to a naturally stimulating object or event and that causes a conditioned response. See also conditioning.
  • discriminative s. a stimulus associated with reinforcement, which exerts control over a particular form of behavior; the subject discriminates between closely related stimuli and responds positively only in the presence of that stimulus.
  • eliciting s. any stimulus, conditioned or unconditioned, which elicits a response.
  • s. generalization in learning by animals stimuli tend to be grouped together, the reactions lacking the discrimination of the higher mammals.
  • s. response coupling coupling of the neural or endocrine stimulus to the cellular response.
  • structured s. a well-organized and unambiguous stimulus, the perception of which is influenced to a greater extent by the characteristics of the stimulus than by those of the perceiver.
  • threshold s. a stimulus that is just strong enough to elicit a response.
  • unconditioned s. any stimulus that is capable of eliciting an unconditioned response. See also conditioning.
  • unstructured s. an unclear or ambiguous stimulus, the perception of which is influenced to a greater extent by the characteristics of the perceiver than by those of the stimulus.
• stimulus-response the key mechanism within the animal that permits it to adapt as perfectly as possible to its environment.

  • s.-r. apparatus a receptor region responding directly to a stimulus, e.g., sound, touch, smell, vision, an afferent neuron that conveys the stimulus toward the central nervous system, a synapse where the afferent path meets the efferent path, an efferent neuron conveying stimuli from the CNS, and an effector (a muscle, gland, or neurosecretory cell).

• sting [sting] 1. injury caused by a noxious substance produced by an animal or plant (biotoxin) and introduced into a patient that it contacts, together with mechanical trauma incident to its introduction. See also insect bites and stings. 2. the organ used to inflict such injury. 3. the illicit prerace administration of a stimulant to a horse with the object of improving its performance.

• stinger tree [sting′er] Dendrocnide moroides.

• stinking willie Seneciojacobaea.

• stinkpeul Acacianilotica subsp. Kreussiana.

• stinkweed see Thlaspi arvense.

• stinkwort see Dittrichia graveolens.

• Stipagrostis grass member of the family Poaceae; awns on the plant become entangled in the forestomachs forming phytobezoars; also cause grass seed abscess. Include S. obtusa (Aristida obtusa), S. ciliata var. capensis (Aristida ciliata).

• stippled [stip′ ld] covered with many small dots.

  • s. cells see basophilic stippling.

• stippling [stip′ling] a spotted condition or appearance, such as an appearance of the retina as if dotted with light and dark points, or the spotted appearance of the erythrocytes in basophilic stippling.

• stirk a heifer or bullock 6–12 months of age.

• stirrup [stur′ p] 1. the stapes, the innermost of the three ossicles of the ear. 2. device usually made of metal, although some are wooden or laminated hard leather, attached by stirrup leathers to the saddle and providing support for the feet of the rider.

• stitch [stich] a loop made in sewing or suturing.

  • s. abscess see stitch abscess.

• Stizostedion old name for the genus Sander in the family Percidae. Includes the walleye.

• St. John’s dog an early name for what was to become the Labrador retriever.

• stochastic [sto-kas′tik] arrived at by skillful conjecturing; allowing the opportunity for variation.

  • s. effect effects that occur by chance and have no threshold level, thought to follow a linear hypothesis In radiation protection, there is no threshold level, and the risk of an effect increases as dose increases. Cancer and hereditary defects are examples of radiation stochastic effects.
• stock livestock.

  • s. equivalents units of livestock measurement used when budgeting feed or assessing productive capacity. All forms of livestock are expressed in terms of one of them, e.g., dry sheep equivalents.
  • s. guard used in lieu of a gate; consists of a pit fitted with steel rollers close enough together to make a satisfactory crossing for a motor vehicle but sufficient to deter livestock. Called also cattle grid.
  • s. horse a riding horse used to work cattle, sheep, or other horses. Small stature, light weight, wiry, fast for a short distance, agile, mostly bay. Called also cow pony, cutting horse.
  • s. and station agent person conducting a rural store dealing in implements, supplies, and livestock pertaining to agricultural pursuits of all kinds.

• Stockard’s paralysis a progressive flaccid posterior paresis and paralysis in young Great Danes and crossbreeds, believed to be a hereditary abiotrophy. There have been no reported cases since 1936.

• stocker weaned calves grazing pasture to enhance growth prior to finishing and slaughter. Commonly grazed through the summer and sold in the Fall as feeder cattle

• Stockholm tar a substance derived from certain species of Pinus spp. by destructive distillation of the wood. Called also wood tar and used extensively as a hoof dressing and general wound protectant.

• stockinet closely woven cotton material used extensively by surgeons mostly in the form of cylinders (e.g., Tubegauze) as a draping technique for surgery, as an undercoat for a plaster cast and as a means of keeping dressings in place on a limb.

• stocking 1. white markings on the lower legs; in horses from the coronet to the carpus or hock and in dogs most of the leg up to the elbow or stifle. 2. populating a farm with animals.

  • set s. the livestock are left on the same pasture, in the same fields or paddocks for long periods, under range conditions often indefinitely. Compare with rotational grazing.
  • s. rate the number of livestock carried per unit of area of pasture. In order to make comparison more rational the procedure is to equate each animal in terms of a standard for the species. See also dry sheep equivalent. animal unit

• stocking-up accumulation of edema fluid in the lower limbs of horses that are not getting sufficient exercise.

• stocks vertical metal or wooden pillars, arranged in a rectangular shape and connected by horizontal bars, designed to restrain a horse or bovine standing within.

• stockwhip a whip used by a mounted horseman to help drive cattle; has a short, 3-ft-long, handle and a long, 10-ft, thong. The best effect is gained by cracking the thong in the air making a sound like a pistol shot. This is achieved by a special snapper at the end of the thong.

• stockyard 1. public saleyard where livestock are sold, usually by auction. 2. yards for working cattle or sheep on private property.

• stoichiology [stoi″ke-ol′ -je] the science of elements, especially the physiology of the cellular elements of tissues.

• stoichiometry [stoi″ke-om′ -tre] the determination of the relative proportions of the compounds involved in a chemical reaction.

• Stokes–Adams disease [stōks′ ad′ mz] a condition initiated by the onset of heart block or ventricular tachycardia whereby cerebral ischemia induces momentary unconsciousness, with or without convulsions.

• stokes (St) [stōk] 1. a unit of kinematic viscosity, that of a fluid with a dynamic viscosity of 1 poise and a density of 1 g per cubic centimeter. Named after George Gabriel Stokes. In the US, using ‘stoke’ indicates the singular. 2. to add fuel or stir.

• Stoll’s method a technique for counting nematode and trematode eggs in a fecal sample. The diluting fluid used is 0.1 M caustic soda solution.

• stolon [sto′lon] an above-ground prostrate stem that develops roots and leaves at nodes along its length, e.g., couch grass.

• stoloniferous said of a plant that propagates its growth by stolons

• stoma [sto′m ] pl. stomas, stomata [Gr.] 1. a mouth-like opening. 2. an incised opening that is kept open for drainage or other purposes, such as the opening in the abdominal wall for colostomy, ureterostomy, and ileal conduit.

• stomach [stum′ k] the curved, muscular, sac-like structure that is an enlargement of the alimentary canal between the esophagus and the small intestine. See also abomasum, reticulum (3), forestomachs, gastric.

  • avian glandular s. see proventriculus.
  • s. bot see Gasterophilus.
  • s. compartments divisions in the stomach complex of camelids are called compartments. Compartment 1 has the equivalent function of the rumen in ruminants, Compartment 2 the equivalent function to the reticulum, and Compartment 3, a long tubular structure, the combined function of the omasum and abomasum with the abomasal function in the terminal part.
  • compound s. a stomach made up of several compartments, e.g., ruminant stomach comprising forestomachs (reticulum, rumen, omasum) and abomasum.
  • glandular s. most aboral part of the stomach in horses; includes cardiac, proper gastric and pyloric glandular zones.
  • hourglass s. one shaped like an hourglass.
  • large s. worm see Haemonchus.
  • s. mesenteries includes mesogastrium, lesser omentum, greater omentum, and omental bursa.
  • muscular s. in birds the gizzard or ventriculus.
  • simple s. a stomach made up of a single compartment, such as is found in humans, carnivores, rabbits, and many rodents. Compare with compound stomach (above).
  • small s. worm Trichostrongylusaxei.
  • s. worm see Gnathostoma spinigerum, Haemonchus, Ostertagia, Teladorsagia, Hyostrongylus, Physaloptera, Ascarops, Physocephalus .

• stomachal [stum′ -k l] pertaining to the stomach; stomachic.

• stomachic [sto-mak′ik] 1. pertaining to the stomach. 2. a stimulant of gastric activity.

• stomatitis [sto″m -ti′tis] inflammation of the mucosa of the mouth. It may be caused by one of many diseases of the mouth, or it may accompany another disease. Both gingivitis (inflammation of the gums) and glossitis (inflammation of the tongue) are forms of stomatitis as are palatitis (or lampas in horses) and cheilitis (inflammation of lips). The specific identification of stomatitis is an important part of a clinical examination in a food animal because of the need to identify the highly infectious vesicular diseases and bluetongue.

  • angular s. superficial erosions and fissuring at the angles (commissures) of the mouth.
  • catarrhal s. diffuse erythema of lips, tongue, cheeks; causes some discomfort and unwillingness to eat.
  • contagious pustular s. see horsepox.
  • erosive s. see erosive stomatitis.
  • erosive–ulcerative s. advanced stage of stomatitis characterized by multiple erosions and deeper ulcers; complete anorexia results.
  • infectious s. a necrotic stomatitis of reptiles caused by various organisms; usually secondary to poor husbandry or predisposing health problems.
  • mycotic s. see mycotic stomatitis.
  • necrotic s. of calves see oral necrobacillosis.
  • papular s. see bovine papular stomatitis.
  • s.–pneumoenteritis complex see peste des petits ruminants.
  • proliferative s. an historically recorded and very rare disease of cattle said to be caused by a filterable agent and recorded only in association with such conditions as chlorinated naphthalene poisoning. The lesions are papular and may also occur on the teats.
  • vesicular s. stomatitis characterized by vesicular lesions that soon rupture to leave denuded areas that become infected, necrotic, even ulcerative. See also vesicular stomatitis, vesicular exanthema of swine, swine vesicular disease, foot-and-mouth disease.

• stomat(o)- word element. [Gr.] relationship to the mouth.

• stomatocyte [sto′m -to-sīt] erythrocyte with an oval-shaped central area of pallor caused by folding of excess cell membrane. May occur as artifacts in thick blood smears or as a hereditary defect. See hereditary stomatocytosis.

• stomatocytosis [sto″m -to-si-to′sis] anemia characterized by the presence of stomatocytes in the blood.

  • hereditary s. occurs in chondrodysplastic dwarf Alaskan malamutes, Drentse patrijshonds with hypertrophic gastritis, and in miniature and standard Schnauzers who remain asymptomatic.

• stomatodeum see stomodeum.

• stomatogastric [sto″m -to-gas′trik] pertaining to the stomach and mouth.

• stomatognathic [sto″m -to-nath′ik] denoting the mouth and jaws collectively.

• stomatology [sto″m -tol′ -je] the study of the mouth and its diseases.

• stomatomalacia [sto″m -to-m-la′she-] softening of the structures of the mouth.

• stomatomycosis [sto″m -to-mi-ko′sis] any fungal disease of the mouth.

• stomatonecrosis [sto″m -to-n -kro′sis] gangrene of the mouth.

• stomatopapilloma [sto″m -to-pap″ľ-lo′m] papilloma on the oral mucosa.

  • eel s. a disease of eels thought to be caused by a virus.

• stomatopathy [sto″m -top′ -the] any disorder of the mouth.

• stomatoplasty [sto′m -to-plas″te] plastic reconstruction of the mouth.

• stomatorrhagia [sto″m -to-ra′j] hemorrhage from the mouth.

• stomocephalus [sto″m n-sef′-l s] a fetus with rudimentary jaws and mouth.

• stomodeum [sto″mo-de′ m] the ectodermal depression at the head end of the embryo, which becomes the front part of the mouth.

• Stomoxys calcitrans [sto-mok′sis] the ubiquitous stable fly, about the size of a house fly, and a pest wherever horses are held. It is a blood-feeder and transmits a number of trypanosomes including Trypanosoma evansi (surra), T. equinum (Mal de Caderas), T. brucei, and T. vivax (nagana of cattle) and is an intermediate host for the equid nematode, Habronema majus. It is probably also involved in the transmission of Dermatophilus congolensis (mycotic dermatitis).

• -stomy word element. [Gr.] creation of an opening into or a communication between.

• stone [stōn] 1. a calculus. 2. a unit of weight, equivalent in the English system to 14 lb avoirdupois.

  • milk s. see milk stone.
  • s. searcher see searcher (2).

• Stonebrink’s medium an egg-based medium for the growth of Mycobacteria bovis.

• stonefish fish member of the family Synanceidae that inhabits coral reefs and has an external appearance similar to a lump of coral. They have a number of spines along the back and if trodden on or bitten eject a very potent poison, which causes severe pain, followed by local swelling and general paralysis ending in fatal respiratory paralysis.

• stones commonly used to describe calculi.

• stool the fecal discharge from the bowels. Normally, only used with reference to the cat and dog. See also feces.

  • lienteric s. feces containing much undigested food.
  • night s. soft, moist fecal pellets ingested by rabbits, directly ftom the anus, usually in the early morning.
  • s. softeners agents such as bulk or lubricant laxatives that result in soft, but formed feces, without causing purgation.

• stootsiekte [Af.] ‘pushing disease’ caused by Matricaria nigellifolia poisoning in southern Africa and characterized by moderate to severe encephalitis, with perivascular microgliosis and perivascular lymphocytic infiltrates.

• stop [stop] the step-like change in lateral profile of the face of dogs at the eyes, where the frontal bones meet the maxilla and nasal bones. It varies greatly between species, being most marked in brachycephalic breeds and barely detectable in Collies and Bull terriers.

• stopcock a valve that regulates the flow of fluid through a tube.

• stopper pad the normally non–weight-bearing footpad located at the posterior aspect of the forelegs, over the accessory carpal bone, in dogs and cats. More commonly called carpal pad; sometimes called stoppers.

• stoppers see stopper pad.

• storage disease any metabolic disorder in which some substance (e.g., fats, proteins, or carbohydrates) accumulates in certain cells in abnormal amounts; called also thesaurismosis, thesaurosis.

  • lipid s. d. any disorder of cellular metabolism that results in accumulation of lipids in tissues, e.g., gangliosidosis, sphingomyelinosis, Gaucher’s disease, globoid cell leukodystrophy, metachromatic leukodystrophy. Called also lipidosis.
  • lysosomal s. d. any inborn error of metabolism in which the deficiency of a lysosomal enzyme results in the accumulation of the substance normally degraded by that enzyme in the lysosomes of certain cells. These diseases are further classified, depending on the nature of the stored substance, as glycogen storage diseases (glycogenoses), sphingolipidoses, mucopolysaccharidoses, and mucolipidoses. Also caused by ingestion of plant toxins, for example, swainsonine.

• storage fungi fungi that are particularly adapted to grow on stored feeds, e.g., Stachybotrys, Aspergillus, Fusarium, and Penicillium spp.

• δ-storage pool disease a blood coagulation disorder due to a defect in δ-granule ADP transport. Characterized by moderate to severe bleeding. Inherited as an autosomal recessive trait in American cocker spaniels. See also thrombocytopathy.

• store English term used with reference to any species. Indicates that the animal is in a lean, lightweight condition, usually young and in most cases recently weaned. They are in a growing in stature phase and ready for good pasture so that in 2–5 months they have grown well and are ready for sale as replacement heifers or to go into lots as feeders.

  • forward s. meat sheep in good enough condition to go to the butcher but in need of topping off to be classified as prime.

• storiform [stor′ľ-form] denoting an irregularly whorled interwoven pattern, somewhat resembling that of a straw mat; said of the microscopic appearance of several types of spindle-cell tumors.

• storksbill see Erodium.

• Stormont test a more sensitive test for tuberculosis in cattle. The test is begun as a single intradermal test by an intradermal injection, usually into a caudal tail fold. The test is read at 72 or 96 hours, and if it is inconclusive a second injection is made at the same site at 7 days after the first injection and the test read 24 hours later. A positive reaction is a 5-mm increase in the thickness of the skin.

• stoss therapy treatment of a disease by a single massive dose of therapeutic agent or by short-term administration of unphysiologically large doses, ‘stoss’ derived from the German word stossen, meaning ‘to push’. Historically, used for a single large dose of vitamin D to treat rickets, but a more current example is a single large dose of glucocorticoid in a patient with septic shock.

• stot steer.

• Stout loop technique a method of wiring between teeth to provide support for fractures of the upper or lower jaws.

• stoutly bred horseman’s expression for a horse bred to stay; bred to run long distance races.

• stover stalks of corn plants from which mature corn cobs have been harvested as grain, or grain sorghum plants from which heads have also been removed. The stover is usually fed by turning the cattle into the field and is subject to fungal infection, sometimes causing mycotoxicosis.

• STPD standard temperature and pressure, dry; denoting a volume of dry gas at 32°F (0°C) and a pressure of 760 mmHg.

• strabismus [str -biz′m s] deviation of the eye that the patient cannot overcome; the visual axes assume a position relative to each other different from that required by the physiological conditions. Called also squint.

  • bilateral convergent s. with exophthalmus inherited in several cattle breeds and usually manifest at ages older than 1 year. Progressive course that advances but may be interrupted by long, apparently stable, periods. Characterized by a bilateral symmetric, permanent rotation of the globes in an anterior-medial direction, resulting in permanent deviation of the visual axis. Accompanied by slight to severe laterodorsal exophthalmus.
  • congenital s. medial strabismus is seen in Siamese cats. See convergent strabismus (below).
  • convergent s. that in which the visual axes converge; esotropia, or crosseye. A frequent finding in Siamese cats, related to an anomaly of neuronal pathways between the retina and lateral geniculate nucleus in which more neurons project contralaterally rather than ipsilaterally as in other cats.
  • divergent s. that in which the visual axes diverge; called also exotropia and walleye.
  • inherited s. see inherited exophthalmos.

    S-88.

    

    Basic types of strabismus.

    S-89.

    

    Advanced bilateral convergent strabismus with exophthalmus in a German brown cow.

  • traumatic s. a complication of traumatic prolapse of the eye, due to rupture of extraocular muscles.

• strabotomy [str -bot′ -me] cutting of an ocular tendon in treatment of strabismus in humans.

• straight [strāt] insufficient angulation of a joint or slope of a bone to give a horse a good conformation, e.g., straight hock, pastern, withers.

• straightbred purebred.

• straights animal feeds that are plain feeds without additions of any sort, e.g., oats, alfalfa hay, although they may have been processed in some way, e.g., cracked or chaffed.

• strain 1. to overexercise. 2. to filter. 3. an overstretching or overexertion of some part of the musculature. 4. excessive effort. 5. One or more characterized organisms within a species or variety. May be distinguished by some particular quality, as rough or smooth strains of bacteria.

  • s. 2 Brucella suis used in a vaccine in China against brucellosis in all target species.
  • s. 19 Brucella abortus see strain 19.
  • s. 45/20 Brucella abortus the strain of reduced virulence used as a living vaccine for adult cattle against bovine brucellosis.
  • s. 51 Salmonella dublin a rough strain with reduced virulence used in Europe to immunize young calves.
  • s. RB51 Brucella abortus a live rough mutant that will immunize cattle but does not induce a reaction to standard serological tests for brucellosis.
  • s. Rev 1 Brucella melitensis live attenuated strain used for vaccination in small ruminants.
  • s. SC54 Salmonella cholerasuis an avirulent organism used live in a vaccine against salmonellosis in swine.
  • s. 9R Salmonella gallinarium a rough strain used as a live vaccine against S. gallinarium and S. enteriditis in poultry.
  • s. MS-H Mycoplasma synoviae a temperature sensitive mutant used to vaccinate chickens.
  • s. ts-11 Mycoplasma gallisepticum a temperature-sensitive mutant used to vaccinate chickens.
  • cell s. see cell culture.
  • compressive s. physical stress that tends to structural compaction.
  • minimum effective s. level of strain below which bone shows no adaptive reaction.
  • tensile s. physical strain that tends toward structural elongation.
• strain 19 naturally occurring mutant, low-virulence strain of Brucella abortus, deficient in its capacity to metabolize erythritol.

  • s. 19 vaccine living vaccine of strain 19 Brucella abortus, the vaccine that made virtual eradication of bovine brucellosis possible.
• straining see tenesmus.

  • s. to defecate tenesmus.

• stramonium [str -mo′ne- m] Datura stramonium.

• strand [strand] a term commonly used to describe one of the two complementary polynucleotide chains found in double-stranded DNA.

  • double s. (ds) nucleic acid occurring as a two-strand helix.
  • lagging s. in DNA replication, the strand in which the nascent strand is synthesized in discontinuous segments after the other or leading strand. See also Okazaki fragments.
  • leading s. in DNA replication, the strand that is copied continuously.

• stranding the largely unexplained migrational phenomenon of cetaceans and pinnipeds in which the animals swim into shallow water and up onto land from where they are unable or unwilling to depart. Single strandings may be due to disease. Multiple strandings may similarly result from illness in the leader of the pod. They are also known to occur in specific locations where the local land appears to confuse the whales’ directionfinding ability. Called also beaching.

• strangles [strang′g lz] an acute highly contagious disease of horses, occurring commonly in outbreaks in breeding stables, racing stables, and others with a continual introduction of new horses, caused by infection with Streptococcus equi subsp. equi, and characterized by fever, purulent rhinitis, pharyngitis, laryngitis, abscessation of the draining lymph nodes, and cough. Low case fatality with treatment, but affected premises are quarantined. Metastatic infection (bastard strangles) occurs infrequently but results in abscess formation in any organ or body site with clinical signs related to the location.

  • puppy s., juvenile s. see juvenile pyoderma.

• strangulated [strang′gu-lāt′ d] congested by reason of constriction or hernial restriction, as strangulated hernia.

• strangulation [strang″gu-la′sh n] 1. arrest of respiration by occlusion of the air passages. 2. impairment of the blood supply to a part by mechanical constriction of the vessels. See also colic (2), intestinal obstruction, intestinal strangulation.

  • epiploic foramen hernia s. rare cause of acute intestinal obstruction in horses.

• stranguria [strang-gu′re- ] strangury.

• strangury [strang′gu-re] slow and painful discharge of urine.

• strap cell [strap] long, flat cells found in some rhabdomyosarcomas.

• strapper stable assistant engaged in the preparation of horses for racing.

• strategic treatment prophylactic treatment, applied particularly in the prevention of parasitic and protozoal diseases, applied at strategic times in the life cycle of the causative agent, rather than on a strictly temporal basis. Compare to tactical treatment.

• Strathmore weed Pimeleaprostrata.

• stratification [strat″ľ-fľ-ka′sh n] 1. arrangement in layers. 2. in statistical terms the division of a population into subpopulations on the basis of specified criteria such as age, breed, parity. See stratified random sample.

• stratiform [strat′ľ-form] occurring in layers.

• stratigraphy [str -tig′r -fe] a method of body section radiography. Replaced by the cross-sectional forms of imaging such as ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI).

• stratum [strat′ m, stra′t m] pl. strata [L.] a sheet-like mass of tissue of fairly uniform thickness; distinct layers making up various tissues or organs, as of the skin, brain, retina.

  • s. avasculosum the avascular stratum in the margin of the iris.
  • s. basale the mitotically active, basal layer of the epidermis, consisting of columnar to cuboidal keratinocytes on a basement membrane.
  • s. corneum the outer horny layer of the epidermis, consisting of cells that are nonnucleated, keratinized, and desquamating.
  • s. germinativum in the epidermis, located between the stratum basale and the stratum granulosum. Together with the basal layer, called the malpighian layer. Called also germinative layer.
  • s. granulosum 1. the layer of cells between the stratum lucidum and the stratum spinosum of the skin, very thin and not always present. Called also the granular layer. 2. the deep layer of the cortex of the cerebellum. 3. the layer of follicle cells lining the theca of the vesicular ovarian follicle. Called also granular layer.
  • s. lamellatum laminae of the hoof corium; see also lamella.
  • s. lucidum the translucent layer of the skin just beneath the stratum corneum. Called also clear layer. Present in the epidermis of the planum nasale of several species and footpads of carnivores.
  • s. spinosum the layer of the epidermis between the stratum granulosum and the stratum basale, marked by the presence of prickle cells; called also spinous layer and prickle-cell layer.
  • s. tectorium the layer of horny scales claimed to exist on the surface of the horse’s hoof that gives it the smooth glossy appearance.

• Strauss reaction [strous] see Strauss reaction.

• straw 1. mature, dry foliage of a cereal crop after the grain has been harvested by a header or by threshing. Has very low digestibility, energy, and protein content. Used principally as bedding but in some economies is used as feed. Causes impaction of the rumen in cattle and ileocecal valve in horses. Is more digestible if chopped and fed with a protein supplement or urea. If left standing in the field is referred to as stubble. When fed in this way there is a variable amount of spilt grain available also. 2. a hollow, plastic tube used for the storage of frozen semen. See also french straws.

  • s. eating a vice in stabled horses that may require muzzling to avoid the occurrence of impaction colic.
  • United States s’s. (2) see french straws.

• strawberry footrot see strawberry footrot.

• strawberry lymph nodes deeply congested lymph nodes such as seen in any septicemia.

• strawberry mark a local granulomatous nodule in the intestinal wall of pigs caused by the deep penetration of the proboscis of Macrocanthoryncus hirudinaceus.

• stray voltage accumulation of low voltages in the metalwork of a milking parlor due either to leakage from poor wiring or to poor earthing (grounding) with no outlet for static electricity. Very small voltages cause restlessness and a fall in milk yield. Stronger currents can cause stunning or even electrocution.

• streak [strēk] a line or stripe.

  • angioid s’s red to black irregular bands in the ocular fundus running outward from the optic disc due to choroidal blood vessels and melanin.
  • s. canal a former name for the papillary duct, the canal between the exterior and the lactiferous sinus within the teat of a ruminant; ductus papillaris.
  • primitive s. a faint white trace at the caudal end of the embryonic disk, formed by movement of cells at the onset of mesoderm formation, providing the first evidence of the embryonic axis and the start of gastrulation.
  • visual s. horizontal band of the ocular fundus dorsal to the optic disc; characterized by an increased concentration of ganglion cells and cone photoreceptors, as well as a relative reduction in retinal vasculature. Presumably a region of higher visual acuity.

• streaked hairlessness irregular, narrow streaks of hairlessness, occurring only in females is recorded in Holstein cattle. Called also streaked hypotrichosis.

• streaking 1. a fault in film radiographs caused by inadequate rinsing or dirty hangers. 2. the process of inoculating microorganisms onto agar media with a loop such that the inoculum is seeded at decreasing concentrations across the media, resulting in isolated colonies of the microorganism.

  • focused grid s. a focused grid placed on the cassette upside down will cause streaking around the edges of the film due to the visible grid lines.
• streamlining physiological phenomenon of blood flow that passes through a vessel without complete mixing so that blood from two different sources and with different composition can flow side by side within the one vessel. Occurs in fetal circulation. Can occur in the portal vein and be the possible explanation for the occasional limitation of lesions of toxopathic hepatitis to one lobe of the liver.

  • s. portal blood flow laminar flow applied to the blood flowing through the portal vein to the liver.

• Streblidae a family of flies similar to the hipposcids and that are found on bats in the tropics and subtropics.

• street nail surgery treatment performed on a traumatic penetrating wound to the equine sole that involves cutting a hole in the sole to allow access to the deep digital flexor tendon and the infected tissue surrounding it (that may include the digital cushion, or the navicular bone and bursa); often caused by the common rusty nail.

• streptavidin [strep-tav′ľ-din] a protein found in Streptomyces griseus that has a high affinity for biotin and is used in a wide range of immunological studies.

• strept(o)- word element. [Gr.] twisted.

• Streptobacillus [strep″to-b -sil′ s] a genus of gram-negative bacteria that sometimes forms filaments. S. moniliformis found in the nasopharynx of rats causes rat bite fever in humans and possibly dogs and cats. They may be acute septicemia or chronic disease characterized by arthritis in mice. Previously called Bacillus actinoides and S. actinoides.

• streptobacillus [strep″to-b -sil′ s] pl. streptobacilli 1. a group of rod-shaped bacteria that remain attached end-to-end in long chains as a result of the failure of daughter cells to fully separate after cell division. 2. an organism of the genus Streptobacillus.

  S-90.

  

  Plate inoculation and streaking method.

• Streptocara a genus of spiruroid nematodes found in the gizzard of many species of birds; the intermediate host is a crustacean.

• streptococcal [strep″to-kok′ l] pertaining to or caused by a streptococcus.

  • s. adenitis a specific disease of pigs; see cervical abscess of pigs. A similar disease occurs in epidemics in dogs in kennels caused by Lancefield Group C Streptococcus. It is characterized by fever, pharyngitis, submaxillary lymph node enlargement, and conjunctival discharge.
  • s. dermatitis on the face of piglets in lesions made by unclipped needle teeth.
  • s. endocarditis see bacterial endocarditis.
  • s. lympadenitis see streptococcal adenitis (above).
  • s. mastitis bovine mastitis caused by Streptococcus agalactiae, S. dysgalactiae, S. uberis.
  • s. meningitis a disease of young pigs caused by Streptococcus suis. There are a number of pathogenic serotypes, but types I and II are particularly prevalent, type I in sucking pigs and type II in weaner pigs. Commonly affected sucking pigs are about 2 weeks old, and show signs of rigidity, hypersensitivity to touch, and tetanic convulsions. There is a dramatic response to penicillin. Most pigs in a litter will be affected, and successive litters will have the disease. There is also a suppurative arthritis. Type II is a zoonosis.
  • neonatal s. septicemia streptococcal infection in newborn calves, piglets, lambs, and puppies causes a syndrome of polyarthritis, meningitis, choroiditis, and in calves an endophthalmitis.
  • s. pneumonia bacterial pneumonia of lambs, calves, and in horses either primary or as secondary infections in viral disease. Infection is usually Streptococcus pneumoniae or S. zooepidemicus.
  • s. polyarthritis common in neonates of all species especially piglets; characterized by pain, heat, and swellings of a number of joints.
  • s. septicemia is part of streptococcal infections in neonates and occurs also in calves caused by Streptococcus pneumoniae. Affected calves show a peracute illness with fever and petechiation of mucosae.

• streptococcemia [strep″to-kok-se′me- ] the presence of streptococci in the blood.

• streptococci [strep″to-kok′si] bacterial members of the genus Streptococcus.

• streptococcosis [strep″to-k $\stackrel{⌣}{o}$ -ko′sis] 1. a disease of domestic poultry caused by Streptococcus zooepidemicus (syn. S. gallinarum), S. faecalis, S. faecium, and S. durans. The disease is characterized by bacteremia with localization of suppurative infection in many body sites and a variety of clinical pictures of fever, anorexia, and pale comb. 2. In fish occurs in farmed warm water species; it is caused by any of several species but predominantly S. iniae and S. agalactiae; manifests as exophthalmia, granuloma-like lesions, and hemorrhaging in the skin, eyes, and visceral organs. Some species of bacteria have been associated with human disease when under-cooked fish were consumed.

• Streptococcus [strep″to-kok′ s] a genus of gram-positive, predominantly aerotolerant cocci in the family Streptococcaceae occurring in pairs or chains. Members are classifiable in several ways, none of them completely satisfactory in isolation in terms of species designation, but useful when combined with biochemical testing. Sherman’s classification was based on tolerance tests. The system used most widely is Lancefield’s grouping based on serological tests. Another means of differentiating streptococci is on the basis of type of hemolysis produced around colonies grown on sheep blood agar. Alpha (α) is partial hemolysis or greening of the agar. Beta (β) hemolysis is seen as a clear zone. Gamma (γ) hemolysis is sometimes used to indicate the absence of hemolysis. Most of the pathogenic species are β hemolytic.

  • S. agalactiae causes mastitis in cattle, goats, and sheep, neonatal septicemia and urogenital infections in dogs and cats. Also causes septicemia in finfish.
  • S. avium, S. durans, S. faecalis, S. faecium and S. gallinarum reclassified in the genus Enterococcus. Now called E. avium etc.
  • S. bovis an important organism in the development of lactic acidosis in cattle following carbohydrate engorgement because of its capacity to ferment starch to lactic acid. Now classified as S. equinus.
  • S. caballi isolated from the hindgut of horses with experimentally induced laminitis.
  • S. canis isolated from cases of septicemia and adenitis in puppies and kittens.
  • S. didelphis associated with suppurative dermatitis in opossums
  • S. dysgalactiae subsp. dysgalactiae causes mastitis in cows, ewes, and goat does and polyarthritis in lambs.
  • S. dysgalactiae subsp. equisimilis causes suppurative arthritis in piglets and abscesses in lymph nodes of the head and neck of horses. Also a cause of cervicitis in mares. Previously called S. equisimilis.
  • S. equi subsp. equi causes strangles in horses.
  • S. equi subsp. ruminatorum isolated from mastitis in small ruminants.
  • S. equi subsp. zooepidemicus occurs as a secondary infection in most species, particularly in horses in wounds, as a cause of cervicitis and a secondary infection associated with the viral infections of the upper respiratory tract. A cause of metritis and mastitis in cattle and septicemia in lambs, pigs, and poultry. Previously called S. zooepidemicus.
  • S. equinus causes opportunist infections in many species. Now includes organisms previously classified as S. bovis.
  • S. gallinaceus a cause of outbreaks of septicemia in chickens
  • S. gallolyticus causes mastitis in cattle, septicemia in poultry, and myositis in pigeons. Includes some organisms previously classified as S. bovis and S. caprinus.
  • S. henryi isolated from the hindgut of horses with experimentally induced laminitis
  • S. ictaluri cause of arthritis, osteolysis, myositis, and spinal meningitis in Channel Catfish broodstock.
  • S. iniae causes disease in cultured finfish.
  • S. ovuberis isolated from a subcutaneous abscess in the udder of a sheep.
  • S. parasuis includes three serotypes previously classified as S. suis. Can cause meningitis and arthritis in pigs.
  • S. parauberis, S. uberis causes mastitis in cows. Have been referred to in the past as S. viridans, a generic term referring to α-hemolytic or nonhemolytic streptococci.
  • S. penaeicida isolated from diseased Pacific white shrimp.
  • S. phocae causes pneumonia and septicemia in seals.
  • S. pneumoniae formerly called Diplococcus pneumoniae; pneumococcus, causes pneumonia in humans, nonhuman primates, guinea pigs, and calves and mastitis in cattle, and septicemia and arthritis in cats.
  • S. plurextorum associated with pneumonia and septicemia in pigs.
  • S. porci isolated from pigs with pericarditis and pneumonia.
  • S. porcinus causes cervical abscess of pigs.
  • S. pyogenes a cause of lymphangitis in foals and an uncommon cause of bovine mastitis. An important pathogen of humans.
  • S. ruminantium a cause of endocarditis in cattle.
  • S. suis has at least 29 capsular types, many of which can cause streptococcal meningitis and arthritis in pigs. There is geographic variance in the importance of individual serotypes but types 1, 2, 3, 4, 7, 8, and 11 are common pathogens. Infection with type 2 is particularly common and is a zoonosis, as is type 14. Immunity to disease can be engendered by vaccination but is serotype specific.

• streptodornase [strep″to-dor′nās] an enzyme produced by hemolytic streptococci that catalyzes the depolymerization of deoxyribonucleic acid (DNA). See deoxyribonuclease.

• streptokinase (SK) [strep″to-ki′nās] an enzyme produced by streptococci that catalyzes the conversion of plasminogen to plasmin, used therapeutically as a thrombolytic agent in the treatment of thrombotic disorders. Usage requires detailed and skilled control to avoid hemorrhage. It may produce severe antigenic reactions upon readministration. See also anticoagulant (2).

  • s.–streptodornase a mixture of enzymes elaborated by hemolytic streptococci; used as a proteolytic and fibrinolytic agent.

• streptolysin [strep-tol′ľ-sin] the hemolysin of hemolytic streptococci.

• Streptomyces [strep″to-mi′sēz] a genus of nonpathogenic soil bacteria, but occasionally parasitic on plants and animals. Notable as the source of various antibiotics, e.g., the tetracyclines, erythromycin (S. erythreus), lincomycin (S. lincolnensis), tylosin (S. fradiae), rifampicin (S. mediterranei), amphotericin B (S. nodosus), and monensin (S. cinnamonensis).

• streptomycin [strep″to-mi′sin] one of the earliest aminoglycoside antibiotics. Because of its widespread use many previously susceptible gram-negative bacteria have developed resistance to it, so it has lost a great deal of its efficacy. It is most effective against leptospira and Haemophilus-associated infections. Like all other members of the group, streptomycin is absorbed poorly from the alimentary tract and must be given parenterally, usually by intramuscular injection, for systemic effect. Although the risk is small, deafness and vestibular disturbances can occur, particularly in cats. Dihydrostreptomycin is a derivative and is used as an alternative to the parent antibiotic.

• Streptopharagus a genus of roundworms in the family Spirocercidae.

  • S. armatus, S. pigmentatus found in the stomach of apes and monkeys.
  • S. kuntzi, S. numidicus found in rats, mice, and gerbils.

• streptosepticemia septicemia due to streptococci.

• Streptothrix bovis see Dermatophilus congolensis.

• streptotrichosis see dermatophilosis.

• streptozocin, streptozotocin [strep″to-zo′sin, strep″to-zo-to′sin] a nitrosurea compound with antineoplastic activity, derived from Streptomyces achromogenes; used principally in the treatment of islet cell tumors of the pancreas.

• stress [stres] 1. forcibly exerted influence; pressure, e.g., compression, tension. 2. the sum of the biological reactions to any adverse stimulus, physical, mental, or emotional, internal or external, that tends to disturb the homeostasis of an organism. Should these reactions be inappropriate, they may lead to disease states. The term is also used to refer to the stimuli that elicit the reactions, e.g., heat, nutritional, lactational, confinement, transportation. See also psychosomatic disease.

  • s. induced diarrhea of the horse see acute idiopathic and chronic undifferentiated diarrhea of the horse.
  • porcine s. syndrome see porcine stress syndrome.
  • s. reaction see alarm reaction.
  • s.-starvation syndrome said of sheep. See pregnancy toxemia.
  • social s. thought to be a common cause of illness in domestic pets and to a less extent in pigs, e.g., in esophagogastric ulcer.
  • s. testing a test for evaluating circulatory response to physical stress produced by exercise. See also exercise testing.

• stress-induced bone lesions most commonly seen in horses doing heavy training. Typical findings include sclerosis of the radial fossa of the third carpal bone, remodeling of the distal epiphysis of the third metacarpal or metatarsal bones.

• stressor any factor that disturbs homeostasis producing stress. In animals there is a long list including nutritional, lactational and pregnancy stress, physical stressors including inclement climate, hard physical work such as endurance rides, racing, capture of wild animals, psychological including weaning, overcrowding, boredom, harassment by humans or other animals, absence of bedding or protection from drafts, and poor ventilation.

• stretch severe passive or active extension of a limb or the trunk.

  • s. injury commonly involves tendons and soft tissues surrounding a joint, particularly of the lower limbs. See dropped carpus.
  • s. receptor see receptor (2).
  • s. relaxation a not universally accepted characteristic of the smooth muscle of the gastrointestinal tract; if the muscle tension is being maintained by regular neural discharge, a distention of the organ that stretches the wall may temporarily inhibit the nervous impulses so that the muscle relaxes and accommodates the new length of the muscle.

• stretches [strech′ z] ‘the stretches’; colloquial name for inherited periodic spasticity.

• stretching disease a description of the clinical signs shown by sheep with intussusception. Called also reksiekte.

• stria [stri′ ] pl. striae [L.] a streak or line. a narrow, band-like structure such as longitudinal collections of nerve fibers in the brain.

  • atrophic s., striae atrophicae atrophic, pinkish or purplish, scar-like lesions in the skin, later becoming white, due to weakening of elastic tissues. Seen in association with canine Cushing’s syndrome.
  • habenular s. a bundle of nerve fibers connecting the olfactory centers with the habenular nuclei.
  • s. mallearis a light band visible through the tympanic membrane when it is examined with an otoscope; is the handle of the malleolus.
  • s. medullares bundles of white fibers across the floor of the fourth ventricle.
• striate, striated [stri′āt, stri′āt- d] having streaks or striae, e.g., striate retinopathy.

  • s. border see brush border.
  • s. duct the intralobular duct of major salivary glands.

• striation [stri-a′sh n] 1. the quality of being streaked. 2. a streak or scratch, or a series of streaks.

• striatonigral [stri″ -to-ni′gr l] projecting from the corpus striatum to the substantia nigra.

  • s. degeneration the basic lesion in hereditary striatonigral and cerebelloolivary degeneration in Kerry blue terriers. See also cerebellar abiotrophy.

• striatonigral-cerebello-olivary degeneration hereditary see striatonigral degeneration.

• stricture [strik′ch r] an abnormal narrowing of a duct or passage, e.g., cervix, esophagus, ureter, urethra. See also stenosis and specific anatomic sites.

  • rectal s. of pigs see rectal stricture.

• stricturization [strik″ch r-ľ-za′sh n] the process of decreasing in caliber or of becoming narrowed or constricted.

• stride the full cycle of the leg’s motion.

  • s.length in gait analysis, the distance between two successive placements of the same foot.
• stridor [stri′d r] a shrill, harsh sound, especially the respiratory sound heard during inspiration in laryngeal obstruction.

  • laryngeal s. that due to laryngeal obstruction. See also roaring.

• stridulation creation of a sound by rubbing two parts of the body together, e.g., cicada.

• strigeids intestinal trematodes of birds; in the family Strigeidae.

• strike [strīk] see cutaneous myiasis.

• striking a vigorous forward pounding action with a front limb. It is an instinctive defense or attack action by a horse that can be very dangerous to an inattentive handler.

• string 1. twine, very thin rope. 2. a term used to denote a group of dairy cattle housed together in a free stall system based on stage of lactation and production with string 1 being the most recently calved and the highestproducing cows, usually containing cows to the time of peak lactation after which they would move to string 2 and subsequently later strings. This allows groups of cattle to be fed separately on the basis of production.

  • s. foreign body see linear foreign body.
  • s. sign seen in radiographs of the stenosed gastric pylorus as contrast medium is forced into the narrow pyloric canal.

• stringent response in bacterial cells, a response to stress when the cell does not have a sufficient pool of amino acids to maintain protein synthesis in which the synthesis of rRNAs and tRNAs is reduced by 20-fold, which suspends many of the cell’s activities until conditions improve.

• stringhalt [string′hawlt] a sporadic disease of horses due to unknown cause. Characterized by involuntary repetitive exaggerated flexion of one or both hocks. A peripheral neuropathy involving the tibial, superficial peroneal, and medial plantar nerves. Spontaneous recovery occurs.

  • Australian s. occurs as extensive outbreaks, often following a drought and associated with the abundance of herbaceous plants, particularly Hypochaeris radicata (called also flatweed, catsear).
  • classical s. the sporadic irreversible, severe form of the disease.

• striocerebellar [stri″o-ser″ -bel′ r] pertaining to the corpus striatum and cerebellum.

• striola a curvilinear landmark in the middle ear to which the hairs (hair cells) in the macula are oriented.

• strip [strip] 1. to press the contents from a canal, such as the urethra, teat canal, or a blood vessel, by running the finger along it. 2. to excise lengths of large veins and incompetent tributaries by subcutaneous dissection and the use of a stripper.

  • s. cup a metal cup with a recessed black lid with a hole covered by wire mesh. To test the first milk of a cow for clots a few streams are squirted onto the lid so that watery milk can be recognized, and some is squirted through the mesh so that any clots present can be detected.
  • s. grazing see strip grazing.

    S-91.

    

    Stringhalt, unilateral. Marked hyperflexion of the affected limb.

  • s. technique used in the treatment of deviated or corkscrew penis in the bull. Depends on the use of strips of fascia lata to anchor the penis or securing the apical ligament of the penis to the dorsum to prevent it from slipping to the side during an erection.
• stripe [strīp] a white mark, narrower than the nasal bones, down the face of a horse. Called also race.

  • dorsal s. the dark brown mark that runs along the middle of the back from the poll to the butt of the tail in donkeys, mules, yellow dun horses, and primitive horses and ponies.
  • eel s. see dorsal stripe (above).

• striped jackCaranx vinctus. Small marine fish

• stripper [strip′ r] surgical instrument for stripping the periosteum from bone. See Matson elevator.

• stripping 1. abattoir technique for removal of esthetically unattractive pleura or peritoneum from a carcass of meat so rendering the meat saleable. 2. a technique for grooming dogs of the terrier type in which dead hairs are pulled out or cut with a razor blade incorporated into the ‘stripping comb’ or knife. The procedure may be a cause of mild folliculitis. 3. see teat stripping. 4. referring to fish culture is the process of removing eggs or sperm from ‘ripe’ broodfish. 5. the selective uptake of pesticide from a dip solution at a rate faster than the removal of water resulting in a decreasing concentration of the chemical as dipping proceeds.

  • fore s. expressing streams of milk from the teat prior to machine milking to determine presence of abnormal milk and to stimulate ‘letdown’.
  • hand s. stripping the last of the milk from the udder by milking the teat manually.
  • machine s. stripping the last of the milk from the udder by pulling down on the teat cup cluster when milk flow has almost ceased; a common but deplored practice is to put a heavy weight on the handpiece at this time.

• strobila [stro-bi′l ] pl. strobilae [L.] the segmented part of an adult tapeworm made up of a chain of proglottides (also spelled proglottids).

• strobilocercus larval stage of a taeniid cestode; a fluid-filled cyst containing a scolex with a pseudosegmented elongated region connecting to the bladder, e.g., Taenia taeniaeformis recently renamed Hydatigera taeniaeformis.

• stroke [strōk] 1. a sudden and severe attack. 2. cerebrovascular accident (CVA).

  • lightning s. see lightning injury.
  • sun s. see heat¹ stroke.

• stroma [stro′m ] pl. stromata [Gr.] the tissue forming the ground substance, framework, or matrix of an organ, as opposed to the functioning part or parenchyma, e.g., stroma iridis, stroma vitreum.

• stromuhr [shtro′moor] an instrument for measuring the velocity of the blood flow.

  • strong ion difference The strong ion difference (SID) is the difference between the positively and negatively charged strong ions in plasma. Strong ions are cations and anions that exist as charged particles dissociated from their partner ions at physiologic pH.
  • strong ion gap reflects the contribution of unidentified anions to the strong ion difference calculated for plasma. It is calculated using the formula:
  • SIG = Atot/(1 + 10(7.08−pH)) − AG, where Atot is the experimentally determined value for the negative logarithm of dissociation constant of plasma nonvolatile weak acids (pK a = 7.08) and AG = anion gap.
• strongyle any roundworm in the superfamily Strongyloidea.

  • large s. includes Craterostomum, Oesophagodontus, Strongylus asini, S. edentatus, S. equinus, S. vulgaris, and Triodontophorus spp.
  • pigeon s. Ornithostrongylusquadriradiatus.
  • small s. includes Caballonema, Cyathostomum, Cylicocyclus, Cylicodontophorus, Cylicostephanus, Cylindropharynx, Gyalocephalus, Poteriostomum and Sinostrongylus.
• Strongyloides [stron″j -loi′dēz] a genus of nematode parasites in the family Strongyloididae, the larvae of which are able to penetrate the intact skin of the host then migrate to the intestine via the bloodstream, lung, trachea and pharynx. Many species are passed from the dam to the young via the milk. See also strongyloidosis.

  • S. avium found in the ceca and small intestine of fowl, turkey, and wild birds.
  • S. cati found in the small intestine of the cat.
  • S. felis in cats.
  • S. fuelleborni found in the small intestine of primates.
  • S. papillosus found in the small intestine of ruminants and rabbits.
  • S. planiceps in cats.
  • S. procyonis found in raccoons.
  • S. ransomi found in the small intestine of pigs.
  • S. ratti found in rats.
  • S. simiae see S. fuelleborni (above).
  • S. stercoralis a species found in the intestine of humans and other mammals, primarily in the tropics and subtropics, usually causing diarrhea and intestinal ulceration.
  • S. tumefaciens associated with tumors of the large intestine of cats.
  • S. venezuelensis found in rats.
  • S. westeri found in the small intestine of horse, pig, and zebra.

• strongyloidiasis [stron″j -loi-di′ -sis] infection with Strongyloides spp. See also strongyloidosis.

• strongyloidosis, strongyloidiasis [stron″j -loi-do′sis] infestation with the nematode Strongyloides, a parasite of the small intestine. Can cause dermatitis and balanoposthitis due to percutaneous entry, or diarrhea when the intestinal infection is very heavy. Autoinfection and transmammary transmission have also been reported in some species. The most important species in domestic animals are S. ransomi in pigs and S. stercoralis in horses. Strongyloides papillosus, a common parasite of ruminants, may be associated with the introduction of organisms into the skin of the feet, causing footrot. In kangaroos, it is a stomach parasite causing gastritis that can be fatal.

• strongylosis [stron″j -lo′sis] infestation of horses with large strongyles (Strongylus edentatus, S. equinus, and S. vulgaris), Triodontophorus spp., Oesophagodontus spp., and some members of the genera Cyclostephanus, Cyathostomum, Cylicocyclus, and the genera Cylicodontophorus, Cylindropharynx, Gyalocephalus, and Poteriostomum. Migration of S. vulgaris larvae cause verminous arteritis and thromboembolic colic. The other Strongylus spp. and the Triodontophorus spp. cause anemia and debility. The small strongyles can cause severe colitis and diarrhea. Called also redworm infestation.

• Strongylus [stron′j -l s] a genus of roundworms in the family Strongylidae. Called also redworms. See also strongylosis.

  • S. asini found in the large intestine of the ass and wild equids.
  • S. edentatus found in the large intestine of horses.
  • S. equinus found in the cecum and colon of equids.
  • S. tremletti found in the rhinoceros.
  • S. vulgaris found in the large intestine of equids; larval stages are found in the anterior mesenteric and other arteries.
• strontium (Sr) [stron′she- m] a chemical element, atomic number 38, atomic weight 87.62.

  • s.-90 is deposited in bones and removed with great difficulty. It has a very long half-life (28.1 years) and if sufficiently ingested, it will have the same toxic and teratogenic effects as external irradiation. S-90 plates are used in the treatment of superficial squamous cell carcinomas involving the eye.
  • s. chloride experimental feeding to pigs causes gross bone abnormality and weakness and paralysis.

• strophanthin, K-strophanthin a cardiac glycoside, obtained from the plant Strophanthus kombé. Has actions similar to ouabain, which is obtained from S. gratus, and scillerin A, obtained from Drimia maritima.

• Strophanthus [stro-fan′th s] an African plant genus in the family Apocynaceae; contain cardiac glycosides, e.g., ouabain, strophanthin; are highly poisonous. Includes S. gratus, S. kombé.

• struck [struk] an acute, highly fatal enterotoxemia of sheep caused by type C Clostridium perfringens. At post mortem, there is peritonitis and myositis. Called also Romney Marsh disease.

• struma [stroo′m ] enlargement of the thyroid gland; goiter.

• strumectomy [stroo-mek′t -me] excision of a goiter.

• strumitis [stroo-mi′tis] thyroiditis.

• struvite [stroo′vīt] magnesium–ammonium–phosphate hexahydrate. See also urolith.

  • s. calculi see struvite uroliths.
  • s. crystalluria a normal finding in cats but large numbers of crystals and, rarely, calculi are found in feline lower urinary tract disease, contributing to obstruction of the urinary tract. Seen in alkaline urine.

• strychnine [strik′nīn] a very poisonous indole alkaloid from seeds of the plant Strychnos nux-vomica and other species of Strychnos. A commonly used compound in malicious poisoning of dogs and used as a feral animal bait to which domestic dogs find access. The dogs may also be poisoned by eating the vermin. Clinical findings include tetanic convulsions especially in response to external stimuli.

• strychnine bush Strychnoslucida.

• Strychnos [strik′nos] a genus of tropical plant species in the family Loganiaceae; they contain strychnine or strychnine-like indole alkaloids including brucine, strychninine, and lucidine and are therefore potentially poisonous. Includes S. lucida, S. nux-vomica, S. psilospermia, S. toxifera (a source of curare).

• Stryker saw a power saw designed to cut plaster casts without cutting the patient. Has a unique oscillating action.

  S-92.

  

  Struvite crystals in urine sediment.

  S-93.

  

  Convulsions in a strychnine-poisoned pig.

• Stryphnodendron South American plant genus in the family Mimosaceae; probably contains tannins that cause hepatitis, nephrosis, diarrhea, photosensitivity. Includes S. adstringens (S. barbadetimam), S. coriaceum S. obovatum.

• STT Schirmer tear test.

• Stuart factor, Stuart–Prower factor factor X, one of the blood clotting factors.

• Stuart–Schwan cocci gram-positive microaerophilic cocci, one of the bacteria found in bovine summer mastitis.

• Stuart’s transport medium a special transport medium for fastidious bacteria.

• stud 1. purebred. 2. a place, usually a farm, at which purebred animals are maintained and reproduced.

  • s. animal an animal registered in a stud book.
  • s. book the register in which the names and parentage of all of the animals that constitute the breed are kept.
  • s. breeder person conducting a business of a stud herd, flock, kennel, cattery etc.
  • s. crud see cannon keratosis.
  • double s. term used in the sheep industry; said of the best lines of rams.
  • s. farm a farm maintained for the purpose of breeding more stud animals.
  • s. herd a herd composed of purebred animals and used for producing more purebred animals.
  • s. tail hyperplasia of the sebaceous glands of the dorsum of the tail (‘tail gland’, ‘supracaudal organ’) in male dogs and cats; often complicated by inflammation and orthokeratotic hyperkeratosis.
  • top s. the best sheep in the stud.
• study [stud′e] a scholarly examination. Specific types of study are also detailed under blind, case-control, cohort, cross-sectional.

  • analytical s. one in which a phenomenon is described, and an attempt made to analyze the effects of variables on the phenomenon.
  • descriptive s. one in which a phenomenon is described but no attempt is made to analyze the effects of variables on the phenomenon.
  • follow-up s. one carried out to find out whether there has been change in the situation since the initial study.
  • longitudinal s. one carried out over a period of time so that chronological time has an opportunity to exert an effect as a variable.
  • observational s. see descriptive study (above).
  • prospective s. one in which the data to be studied are yet to be generated, the events having not yet occurred. The design for establishing relationships between the outcome of interest and exposure variables.
  • retrospective s. one based on examination of existing data, on events that have already occurred. Allows the formulation of ideas and preliminary measures of associations and investigation of the effect of an exposure on an outcome.
  • simulation s. one in which the real circumstances are simulated, either in fact, or by means of a set of mathematical formulae each of which expresses the probability of each outcome in a series of consequential events that mirror the possible pathways in a real-life situation.

• stumbling an abnormal gait in which the animal does not fully extend the limb, the plantar surface is not properly placed with respect to the ground surface at the time of impact so that the limb is likely to collapse and the animal to fall.

• stump [stump] the distal end of a limb, tail, or organ, e.g., uterine stump, left after amputation of the limb or organ.

• stump sucker see crib-biting.

• stumped-up toe the toe of a horse’s hoof that has been severely rasped back to make it coincide with a shoe that has been set too far back. A major fault in shoeing.

• stumpy generally refers to a very short tail, as found in Stumpy-tail cattle dog; also a variety of Manx cat with a mobile, often deformed, tail.

• Stumpy-tail cattle dog a medium-sized dog with pricked ears and short coat, except around the neck where it forms a ruff. It can be blue, blue mottled, or red speckled with solid-colored patches. The tail is naturally short.

• stunner device used in abattoirs to stun an animal so that it is unconscious when it is bled out.

  • concussion s. a captive-bolt, nonpenetrating device, activated by a standard cartridge. The explosion drives a mushroom-shaped head out of the handheld pistol that has been placed against the animal’s forehead. Has the same effect as a hammer blow but is less subject to error or danger.
  • electrical s. the passage of a low voltage electrical current through the brain to cause unconsciousness. The current is passed through a pair of tongs clamped to the head like a pair of earphones. Used mostly for pigs and poultry but also for lambs and calves. The tongs should be applied for at least 10 seconds and the amperage not less than 250 milliamps and the voltage not less than 75 volts. See also stunning.
  • penetrating captive-bolt s. the bolt that is driven out of the pistol (see concussion stunner above) is a 0.5-in.-diameter rod that penetrates the skull bones and lacerates the brain.
  • pneumatic s. a penetrating captive-bolt unit (see above) in which the power is compressed air. Has problems when the compressor is not functioning.

• stunning [stun′ing] producing unconsciousness by a blow. See stunner. Various methods are used including a hammer blow, free bullet using a number of different projectiles, immersion of the head in carbon dioxide gas, electric shock, all of them aiming to allow the animal to bleed out while it is still alive. An animal that is dead before it has bled out will be unsuitable for marketing.

• stunted chick disease see infectious stunting syndrome.

• stunting/runting syndrome see infectious stunting syndrome.

• stupe a hot, wet cloth, or sponge, charged with a medication for external application.

• stupefacient [stoo″p -fa′sh nt] an agent that induces stupor.

• stupefactive [stoo″p -fak′tiv] producing narcosis or stupor.

• stupor [stoo′p r] decreased level of consciousness with no response to any except noxious stimuli.

• sturdy [stur′de] neurological disease in sheep caused by the pressure of a Taenia multiceps metacestode. Called also gid.

• sturgeon fish of the family Acipenseridae. Valued for their flesh and the production of caviar.

• Sturges’ rule a guide as to the number of categories into which a set of data should be divided for analysis or presentation: number of categories = 1 + 3.3 log N, where N = number of individuals in collected data.

• Stuttgart casting a complicated technique for casting a horse that utilizes three ropes, a surcingle and two hobbles.

• Stuttgart disease canine leptospirosis.

• stye see external hordeolum.

• style [stīl] a term used in subjective appraisal of wool; combines brightness, density, character, dust penetration and tip shape.

• stylet [sti′l t] 1. a wire run through a catheter or cannula to render it stiff or to remove debris from its lumen. 2. a slender probe.

• stylo see Stylosanthes.

• styl(o)- word element. [L., Gr.] relationship to the styloid process of the temporal bone.

• stylohyoid [sti″lo-hi′oid] pertaining to the styloid process and hyoid bone or to the stylohyoid bone. See stylohyoideum.

• stylohyoideum the stylohyoid bone, the largest element of the hyoid apparatus, a paired bone (one on each side) that articulates with the cartilaginous tympanohyoid dorsocaudally and the epihyoid rostroventrally.

• styloid [sti′loid] long and pointed, like a pen or stylus.

  • s. process 1. a pen-like process, as found at the distal end of the radius and the ulna, or of the auricular cartilage. 2. a small blunt cartilaginous process at the base of the petrous temporal bone.

• styloiditis [sti″loi-di′tis] inflammation of tissues around the styloid process of the temporal bone.

• stylomastoid [sti″lo-mas′toid] pertaining to the styloid and mastoid processes of the temporal bone.

• stylomaxillary [sti″lo-mak′sľ-lar″e] pertaining to the styloid process of the temporal bone and the maxilla.

• stylopodium [sti″lo-po′de- m] segment of a limb corresponding to the upper arm (brachium) or thigh.

• Stylosanthes a perennial legume genus in the plant family Fabaceae; adapted to grow in many environments. An alternative to lucerne (alfalfa) in tough environments. Includes S. humilis (Townsville stylo). Called also stylo, Brazilian lucerne.

• stylus 1. a stylet. 2. a pencil or stick, as in a styptic pencil.

• Stypandra glauca Australian member of the plant family Liliaceae; contains stypandrol that causes retinal degeneration, degeneration of optic nerves followed by blindness, incoordination, posterior paresis. Called also S. grandiflora, S. imbricata, blind grass or candyup poison.

• stypandrol neurotoxic naphthaquinone plant toxin found in Stypandra, Dianella, Hemerocallis spp.

• stype a tampon or pledget of cotton.

• stypsis [stip′sis] 1. astringency; astringent action. 2. use of a styptic.

• styptic [stip′tik] 1. arresting hemorrhage by means of an astringent quality. 2. an agent that arrests hemorrhage by means of an astringent quality; a markedly astringent remedy. A chemical styptic works by causing the formation of a blood clot by chemical action. A vascular styptic checks bleeding by causing the blood vessels to constrict. A mechanical styptic assists clotting by mechanical means; for example, when one applies a piece of paper or cotton to a slight razor cut.

• Stypven time [stip′v n] see Russell’s viper venom time.

• stywesiekte [Af.] ‘stiff sickness’, a pyrrolizidine toxicosis in livestock caused by Crotalaria burkeana, C. barkae, C. steudneri; characterized by painful hoof lesions.

• sub- word element. [L.] under, less than.

• subacromial [sub″ -kro′me- l] below the acromion.

• subacute [sub″ -kūt′] somewhat acute; between acute and chronic.

• subalimentation [sub″al-ľ-m n-ta′sh n] insufficient nourishment.

• subaortic, subaortal [sub″a-or′tik] below the aorta.

  • s. septal defect ventricular septal defect in the membranous part of the interventricular septum.
  • s. stenosis see aortic subvalvular stenosis.

• subaponeurotic [sub″ap-o-n $\stackrel{⌣}{o}$ $\stackrel{⌣}{o}$ -rot′ik] below an aponeurosis.

• subarachnoid [sub″ -rak′noid] between the arachnoid and the pia mater.

  • s. block see subarachnoid block.

• subareolar [sub″ -re′-l r] beneath the areola of the nipple.

• subastragalar [sub″ s-trag′-l r] below the astragalus (talus).

• subastringent [sub″ -strin′j nt] moderately astringent, less astringent than other agents.

• subaural [s b-aw′r l] below the ear.

• subcapsular [s b-kap′su-l r] below a capsule.

• subcartilaginous [sub″kahr-tľ-laj′ľ-n s] 1. below a cartilage. 2. partly cartilaginous.

• subcellular organelles discrete, functioning structures within cells, e.g., mitochondria, nucleus, Golgi apparatus, and lysosomes.

• subcephalic pocket a transverse furrow beneath the rostral margin of the forebrain.

• subchondral [s b-kon′dr l] below the cartilage.

  • s. bone providing support for the cartilage of the articular surface.
  • s. cysts in the subchondral bone, usually an indication of osteochondrosis.

• subclass [sub′klas] a taxonomic category subordinate to a class and superior to an order.

• subclavian [s b-kla′ve- n] literally means under the clavicle.

• subclinical [s b-klin′ľ-k l] without clinical manifestations; said of the early stages or a very mild form of a disease, e.g., subclinical disease, infection, parasitism, or when a disease is detectable by clinicopathological tests but not by a clinical examination.

• subcloning a restriction fragment of an original DNA that has been cloned may be further digested with another restriction enzyme and the smaller fragments cloned.

• subconjunctival [sub″k n-jnk-ti′v l] pertaining to the zone beneath the conjunctiva, e.g., subconjunctival hemorrhage, subconjunctival infection.

• subcoracoid [s b-kor′ -koid] situated under the coracoid or coracoid process.

• subcorneal [s b-kor′ne- l] beneath the stratum corneum.

• subcortex [s b-kor′t ks] the brain substance underlying the cortex.

• subcostal [s b-kos′t l] caudal to a rib or ribs.

• subcranial [s b-kra′ne- l] beneath the cranium.

• subcrepitant [s b-krep′ľ-t nt] somewhat crepitant in nature; said of a rale.

• subculture [sub′k l-ch r] a culture of microorganisms derived from another culture.

• subcutaneous [sub″ku-ta′ne- s] immediately beneath the layers of the skin.

  • s. abscess the most common site of an abscess; causes local pain and swelling and is confirmed by purulent material withdrawn by needle puncture and aspiration
  • s. edema accumulation of edema in subcutaneous tissues, usually of the dependent parts. If extensive referred to as anasarca. See also edema.
  • s. emphysema accumulation of gas subcutaneously resulting from causes such as air entering through a cutaneous wound, extension from pulmonary emphysema, gas gangrene.
  • s. fat necrosis manifested by many inert, painless lumps in the subcutis, is inherited in cattle.
  • s. hemorrhage the accumulation of blood in a subcutaneous site such as occurs in purpura hemorrhagica.
  • s. tissue the layer of loose connective tissue directly under the skin.

• subcuticular [sub″ku-tik′u-l r] below the epidermis.

• subcutis [s b-ku′tis] the subcutaneous tissue.

  • hoof s. the connective tissue layer that attaches the dermis to the deeper structures of the hoof. Is thin in most places but thick in the coronary and digital cushions.

• subdiaphragmatic [sub″di- -frag-mat′ik] caudal to the diaphragm.

• subduct [s b-dukt′] to draw down or deviate downward; see infraversion (1).

• subdural [s b-doo′r l] between the dura mater and the arachnoid.

  • s. abscess usually extensions from paranasal sinuses, e.g., in cattle after dehorning; localizing signs, head rotation, depending on location and volume of space occupied.
• subendocardial [sub″ n-do-kahr′de- l] beneath the endocardium.

  • s. coat layer of loose connective tissue beneath the endocarium.
  • s. fibrosis may be present at birth or acquired as a result of prolonged dilatation or as a result of persistent local turbulence as in the jet lesions caused by leaking cardiac valves.
  • s. mineralization may accompany subendocardial fibrosis or muscular degeneration or in association with persistent hypercalcemia or uremia.
• subendothelial [sub″ n-do-the′le- l] beneath an endothelial layer.

  • s. coat a layer of connective tissue and fibroblasts beneath the endothelium of blood vessels and the heart.
  • s. space potential connective tissue space beneath the endothelium of blood vessels and the heart.

• subepidermal [sub″ep-ľ-der′m l] beneath the epidermis.

• subepiglottic [sub″ep-ľ-glot′ik] below the epiglottis; see pharyngeal.

  • s. cyst in adult horses can cause decreased exercise tolerance or respiratory stridor and in foals or young horses it can cause dysphagia. Can be congenital or acquired.

• subepithelial [sub″ep-ľ-the′le- l] beneath the epithelium.

• subestrus a very weak display of estral signs. See also silent estrus.

• subfamily [s b′fam-ľ-le] a taxonomic division sometimes established, subordinate to a family and superior to a tribe.

• subfascial [s b-fash′ l] beneath a fascia.

• subfebrile marginally febrile.

• subfertility reduced fertility.

• subgallate a reduced salt of gallic acid, which is a hydrolysis product of tannins extracted from nutgalls or the spent broths of some antibioticproducing fungal cultures. It is used as a styptic, intestinal astringent, and as a topical astringent in diseases of the skin. See also bismuth subgallate.

• subgenus [s b′je-n s] a taxonomic category sometimes established where the number of specimens is large, but not generally used; subordinate to a genus and superior to a species.

• subgingival [s b-jin′jľ-v l] a position on the tooth between the gingival margin and the bottom of the gingival sulcus or periodontal pocket.

  • s. resorptive lesion see tooth resorption.

• subglenoid [s b-gle′noid] beneath the glenoid (mandibular) fossa.

• subglossal [s b-glos′ l] below the tongue.

• subglottic [s b-glot′ik] below the glottis.

  • s. stenosis see laryngeal stenosis.

• subgrondation [sub″gron-da′sh n] depression of one fragment of bone beneath another.

• subhepatic [sub″h -pat′ik] below the liver.

• subhyoid [sub-hi′oid] below or caudal to the hyoid bone.

• subiculum [s -bik′u-l m] an underlying or supporting structure.

• subiliac [s b-il′e-ak] below the ilium.

• subinvolution [sub″in-vo-loo′sh n] incomplete involution; failure of a part to return to its normal size and condition after enlargement from functional activity.

  • s. of placental sites failure of involution of the sites of placental attachment in a postpartum bitch; causes persistent intrauterine bleeding.

• subjacent [s b-ja′s nt] located below.

• subject [s b-jekt′] an animal subjected to treatment, observation, or experiment.

  • s. contrast in radiology, the difference in relative opacities within the subject as distinct from the differences between the subject and the surroundings.

• subjective [s b-jek′tiv] in veterinary medicine, case information as perceived or interpreted by the owner or veterinarian since the patients are unable to speak for themselves; not measurable or factual. The patient cannot describe their pain, but their behavior in response to the pain is evaluated.

• subjugal [s b-joo′g l] below the zygomatic bone.

• sublatio retinae detachment of the retina. See retinal detachment.

• sublesional [s b-le′zhn- l] performed or situated beneath a lesion.

• sublethal [s b-le′th l] insufficient to cause death.

• sublimate [sub′lľ-māt] 1. a substance obtained by sublimation. 2. to accomplish sublimation.

• sublimation [sub″lľ-ma′sh n] the conversion of a solid directly into the gaseous state.

• sublingual [s b-ling′gw l] beneath the tongue.

  • s. gland a salivary gland on either side under the tongue.

• sublinguitis [sub″ling-gwi′tis] inflammation of the sublingual gland.

• sublobular veins [s b-lob′u-l r] veins that merge to form hepatic veins that receive tributaries from the central veins of liver lobules.

• subluxate [s b-luk′sāt] to partially dislocate.

• subluxation [sub″l k-sa′sh n] a partial dislocation of a joint. In the terminology of chiropractic, an abnormal positional relationship between contiguous vertebrae resulting in abnormal biochemical and neurological function.

  • angle of s. in the Ortolani maneuver, the point at which the hip luxates. See also angle of reduction.
• submandibular [sub″man-dib′u-l r] below the mandible.

  • s. salivary glands see salivary gland.
  • s. swelling the swelling may be soft as in edema or hard and painful as in grass seed abscess, or lymphadenitis or inflammation of salivary glands. The accumulation of edema fluid is characteristic of grazing animals or those eating off the ground. Cows eating from a manger will not be affected. Called also bottle jaw.

    S-94.

    

    Submandibular abscess in a cow.

• submaxilla [sub″mak-sil′ ] the mandible.

• submaxillaritis [s b-mak″sľ-l r-i′tis] inflammation of the submaxillary gland.

• submaxillary [s b-mak″sľ-lar′e] below, caudal or ventral to the maxilla.

  • s. gland the mandibular salivary gland.
• submental [s b-men′t l] below the chin.

  • s. organ a collection of large sebaceous glands located on the chin of cats.

• submersion [s b-mur′zh n] the act of placing, or the condition of being under, the surface of a liquid.

• submetacentric [sub″met- -sen′trik] having the centromere almost, but not quite, at the metacentric position.

• submicroscopic [s b-mi″kro-skop′ik] too small to be visible with the microscope.

• submission yielding; not offering resistance. See appeasement behavior.

  • s. rate percentage of cows in a herd that come on heat and that are mated during a specified period, usually a month; the difference, i.e., those that come on heat and are not mated, are the deferred mating group.

• submucosa [sub″mu-ko′s ] connective tissue situated beneath a mucous membrane.

• submucosal glands [sub″mu-ko′s l] glands of the lamina epithelialis mucosae that perforate the lamina muscularis, with their adenomeres located in the submucosal connective tissue.

• submucous [s b-mu′k s] beneath a mucous membrane.

• subnarcotic [sub″nahr-kot′ik] moderately narcotic; less narcotic than other agents.

• subneural [s b-n$\stackrel{⌣}{o}$ $\stackrel{⌣}{o}$′r l] beneath a nerve.

• subnormal [s b-nor′m l] below or less than normal.

• subnormality [sub″nor-mal′ľ-te] a state less than normal or that usually encountered, below the reference range for quantitative assessments

• suboccipital [sub″ok-sip′ľ-t l] below the occiput.

• suborbital [s b-or′bľ-t l] beneath the orbit.

• suborder [sub′or-d r] a taxonomic category sometimes established, subordinate to an order and superior to a family.

• subpalpebral underneath the eyelid.

  • s. lavage see subpalpebral lavage tube.

• subpapular indistinctly papular.

• subpatellar [sub″p -tel′ r] below the patella.

• subfertility [sub″f r-til′ľ-te] marginal fertility.

• subpericardial [sub″p r-ľ-kahr′de- l] beneath the pericardium.

• subperiosteal [sub″p r-e-os′te- l] beneath the periosteum.

• subperitoneal [sub″p r-ľ-to-ne′ l] beneath the peritoneum.

• subpharyngeal [sub″f -rin′je- l] beneath the pharynx.

• subphrenic [s b-fren′ik] caudal to the diaphragm.

• subphylum [s b-fi′l m] pl. subphyla [L.] a taxonomic category sometimes established, subordinate to a phylum and superior to a class.

• subpineal below the pineal body.

• subplacenta [sub″pl -sen′t] below the placenta.

• subpleural [s b-ploor′ l] beneath the pleura.

• subpreputial [sub″pre-pu′sh l] beneath the prepuce.

• subpubic [s b-pu′bik] beneath the pubic bone.

• subpulmonary [s b-pool′mo-nar″e] beneath the lung.

• subretinal [s b-ret′ľ-n l] beneath the retina; between the neurosensory retina and retinal pigment epithelium.

• subscapular [s b-skap′u-l r] below or caudal to the scapula.

• subscription [s b-skrip′sh n] the third main part of a drug prescription, comprising directions to be followed by the pharmacist in its preparation.

• subserous [s b-sēr′ s] beneath a serous membrane.

• subsolar beneath the sole of the horse’s hoof.

  • s. abscess usually a consequence of a nail prick causing lameness. See foot abscess.

• subspecies [sub′spe-sēz] a subdivision of a species; a variety or race.

• subspectacular pertaining to the region beneath the spectacle that covers the eye in snakes and ablepharine lizards which lack eyelids.

  • s. abscess accumulation of inflammatory cells in the subspectacular space, usually as a result of an ascending infection from the mouth via the lacrimal duct in individuals with stomatitis.
  • s. space tear-filled space between the cornea and spectacle.

• substage [sub′stāj] the part of the microscope underneath the stage.

• substance [sub′st ns] the material constituting an organ or body.

  • black s. substantia nigra.
  • controlled s. see Controlled Substances Act.
  • depressor s. a substance that tends to decrease activity or blood pressure.
  • gray s. nerve tissue composed of predominantly nerve cell bodies, unmyelinated nerve fibers, and supporting tissue. See also gray matter.
  • ground s. the gel-like material in which connective tissue cells and fibers are embedded.
  • medullary s. 1. the white matter of the central nervous system, consisting of axons and their myelin sheaths. 2. the soft, marrow-like substance of the interior of such structures as bone, kidney, and adrenal gland.
  • s. P an undecapeptide present in the intestine, where it induces contraction of the intestine and dilatation of blood vessels; it is also present in a number of neuronal pathways in the brain and in primary sensory fibers of peripheral nerves, and may be a neurotransmitter associated with transmission of pain impulses.
  • perforated s. 1.anterior perforated substance, an area anterolateral to each optic tract, pierced by branches of the anterior and middle cerebral arteries. 2.posterior perforated substance, an area between the cerebral peduncles, pierced by branches of the posterior cerebral arteries.
  • pressor s. a substance that raises blood pressure.
  • reticular s. the netlike mass of threads seen in erythrocytes after vital staining.
  • slow-reacting s. see slow-reacting substance.
  • threshold s’s those substances (e.g., glucose) excreted into the urine only when their concentration in plasma exceeds a certain value.
  • white s. tissue consisting mostly of myelinated nerve fibers and constituting the conducting portion of the brain and spinal cord; see also white matter.
• substantia [s b-stan′she-] pl. substantiae [L.] substance.

  • s. alba the white matter of the spinal cord and the brain.
  • s. compacta compact bone.
  • s. gelatinosa the substance sheathing the posterior horn of the spinal cord and lining its central canal.
  • s. grisea the gray matter of the spinal cord and brain.
  • s. grisea centralis the central gray matter that surrounds the cerebral aqueduct.
  • s. nigra the layer of gray substance separating the tegmentum of the midbrain from the crus cerebri.
  • s. propria corneae layer of transparent lamellated fibrous connective tissue that constitutes the bulk of the cornea; composed of collagen fibers disposed in plate-like formations, fibroblasts, and ground substance with many nerve fibers but no blood vessels.
  • s. propria choroid loose connective tissue of the choroid.

• substernal [s b-stur′n l] deep to the sternum.

• substituent [s b-stich′u- nt] 1. a substitute; especially an atom, radical, or group substituted for another in a compound. 2. of or pertaining to such an atom, radical or group.

• substitution [sub″stľ-too′sh n] the act of putting one thing in the place of another, especially the chemical replacement of one atom or substituent group by another.

  • conservative s. in protein chemistry, one amino acid is substituted by another that has a similar polarity.
  • meat s. a fraud in the meat industry in which uninspected meat is substituted for meat that has undergone inspection and been branded as satisfactory. The other not infrequent fraud is the substitution of meat of another species, e.g., horse for beef, cat for chicken or rabbit.
  • nonconservative s. in protein chemistry, one amino acid is substituted by another that has a markedly different polarity.

• subsylvian [s b-sil′ve- n] situated deep in the lateral sulcus (sylvian fissure) of the brain.

• subsynaptic web the web of filaments in the postsynaptic membrane, i.e., on the effector organ.

• subtarsal [s b-tahr′s l] below the tarsus.

• subtentorial [s b″ten-to′re- l] ventrocaudal to the tentorium of the cerebellum, depending on the position of the animal.

• subthalamus [s b-thal′-m s] the ventral thalamus or subthalamic tegmental region: a transitional region of the diencephalon interposed between the (dorsal) thalamus, the hypothalamus, and the tegmentum of the mesencephalon (midbrain); it includes the subthalamic nucleus and the zona incerta, all with unknown functions.

• subtle [sut′ l] 1. very fine, as a subtle powder. 2.

• subtraction radiography [sub-trak′sh n] a radiographic technique in which a precontrast radiograph is obtained of a body part. This image is converted into a mask image with an inverse contrast scale. Following contrast administration multiple radiographs of the same part are obtained, and the mask image is subtracted from the contrast images. This technique produces a high-contrast image of the blood vessels with decreased visualization of the surrounding structures. Used in angiography.

  • digital s. r. The use of computed techniques to create the mask and subsequent images. This has replaced traditional subtraction radiography. The use of computers allows motion correction of the images and an improvement in image quality.

• subtribe [sub′trīb] a taxonomic category sometimes established, subordinate to a tribe and superior to a genus.

• Subtriquetra a genus of pentastomes in the family Porocephalidae found in fish (the nymphs) and crocodiles (the adults).

• subtrochanteric [sub″tro-kan-ter′ik] below the trochanter of the femur.

• subtympanic [sub″tim-pan′ik] somewhat tympanic in quality.

• Subulura a large genus of roundworms in the family Subuluridae.

  • S. brumpti occurs in the ceca of fowls, turkey, guinea fowl, and related wild birds and has low pathogenicity.
  • S. differens occurs in fowls and guinea fowl.
  • S. minetti occurs in chickens.
  • S. strongylina found in chickens, guinea fowl, and wild birds.
  • S. suctoria found in the ceca of chickens and wild birds.

• subungual [s b-ung′gw l] beneath a nail or claw, e.g., nailbed.

• subunit vaccine see subunit vaccine.

• suburethral [sub″u-re′thr l] beneath the urethra.

• subvaginal [s b-vaj′ľ-n l] under a sheath, or below the vagina.

• subvalvular [s b-val′vu-l r] below the heart valves.

  • s. aortic stenosis see aortic subvalvular stenosis.

• subvertebral [s b-vur′t-br l] on the ventral side of the vertebrae.

• subvirile [s b- vir′il] having deficient virility.

• subvolution [sub″vo-loo′sh n] the operation of turning over a flap to prevent adhesions.

• succenturiate [suk″s n-tu′re-āt] accessory; serving as a substitute.

  • s. lobe particularly when referencing the discoid placenta (humans, rodents), succenturiate lobe is a smaller, accessory placenta separate from the main portion.

• succimer [suk′sľ-m r] see dimercaptosuccinic acid.

• succinate [suk′sľ-nāt] any salt of succinic acid.

  • s. dehydrogenase an enzyme of the TCA cycle, located in the inner mitochondrial membrane that splits off hydrogen from succinic acid producing fumarate and FADH₂. A component of Complex II (succinate-Coenzyme Q reductase) of the electron transport chain.

• succinic acid [s k-sin′ik] a 5-carbon dicarboxylic acid, intermediate in the tricarboxylic acid cycle.

• succinimides [s k-sin′ľ-mīd] a group of anticonvulsant drugs that includes phensuximide, methsuximide, and ethosuximide. Not widely used in animals.

• Succinimonas amylolytica a common finding among the digestive bacteria in the rumen.

• Succinivibrio dextrinosolvens a bacterial digester of ruminal contents.

• succinyl-CoA [suk′sľ-n l] succinic acid linked to Coenzyme A, a high-energy intermediate metabolite formed in the Krebs cycle by the oxidation of α-ketoglutaric acid.

• succinylcholine [suk″sľ-n l-ko′lēn] a short-acting depolarizing neuromuscular blocking agent used as a muscle relaxant. Called also suxamethonium or suxamethonium chloride.

  • s. chloride the pharmaceutical form of succinylcholine; can cause death by cardiac arrest even in healthy horses.

• succinylsulfathiazole [suk″sľ-n l-sul″f-thi′ -zōl] a sulfonamide drug used for treatment of enteric infections because it is poorly absorbed and maintains high concentrations in the gut. Called also sulfasuxidine.

• Succisa pratensis see Scabiosa succisa.

• succorrhea [suk″o-re′ ] excessive flow of a natural secretion.

• succus pl. succi [L.] any fluid derived from living tissue; bodily secretion; juice.

  • s. entericus the secretion of the intestinal glands.

• succussion [s -kush′ n] 1. shaking of the body or part of it to elicit a sound indicative of fluid and air in a body cavity. 2. in homeopathy a term describing violent shaking (mixing) to increase the purported potency of a remedy.

• suck reflex [suk] see sucking reflex.

• sucking the application of suction to an object by the mouth.

  • cross s. group-housed milk-fed calves will sometimes suck each other, but this can be greatly reduced or eliminated if calves consume their milk ration via free access to a teat.
  • s. drive instinctive enthusiasm of the neonate to suck on a teat, or any object that even remotely resembles a teat.
  • navel and prepuce s. occurs in group-reared calves fed milk-replacer.
  • s. order within a litter, piglets establish a sucking order by social interaction and fighting that results in each piglet generally sucking off the same teat and the larger birth weight piglets sucking the anterior teats on the udder as the anterior sections of the sow’s udder give more milk than the posterior sections. Also the derivation for the term ‘to be left sucking the hind teat’.
  • s. reflex sucking movements of the lips of newborn and unweaned animals elicited by placing a warm, fleshy mass in the animal’s mouth.
• suckler a young animal that is still drawing milk from its dam; a nursing female animal, usually a cow.

  • s. herd a herd of cattle composed of dams and their young calves up to the point of weaning.

• Suckleya suckleyana North American member of the plant family Chenopodiaceae; can cause cyanide poisoning. Called also poison suckleya.

• suckling the nursing of the young by the dam; the young animal so nursed.

  • multiple s. when a cow accepts more calves to suckle than her own; a system for foster-rearing of orphan or purchased calves.

• sucralfate [soo-kral′fāt] a complex of aluminum hydroxide and sulfated sucrose used for short-term protection of gastric mucosa; it forms a complex with proteins that resists digestion by acid and pepsin thereby making a protective coating for ulcerations.

• sucrase [soo′krās] an intestinal enzyme that hydrolyzes the disaccharide sucrose to its constituents of glucose and fructose, enabling the absorption of these compounds. Sucrase activity varies with age and species.

• sucrose [soo′krōs] a sugar obtained from sugar cane, sugar beet, or other sources; used as a food and sweetening agent. Digestion is by sucrase secreted in the succus entericus. The feeding of large amounts to newborn and very young animals will cause osmotic diarrhea because of failure to hydrolyze the sugar. Overfeeding of ruminants with sucrose, or molasses, its crude form, causes carbohydrate engorgement.

• suction [suk′sh n] aspiration of gas or fluid by mechanical means.

  • posttussive s. a sucking sound heard over a lung cavity just after a cough.
  • s. tip sterilizable metal, handheld instrument, used for suction by inserting into the end of a suction tube. Has an angled neck for reaching into difficult pockets and a small bulb on the end with many holes in it to permit placing it on tissue without obstructing the suction. Called also Yankauer tip.

• suctioning removal of material through the use of negative pressure, as in suctioning an operative wound during and after surgery to remove exudates.

• suctorial [s k-tor′e- l] adapted for sucking.

• sudamen [soo-da′m n] pl. sudamina [L.] a small whitish vesicle caused by retention of sweat in the layers of the epidermis.

• Sudan [soo-dan′] a group of lipophilic azo compounds used as biological stains for fats, e.g., Sudan III, Sudan IV.

  • S. stain test a useful screening test for steatorrhea. Feces mixed with Sudan III or Sudan IV stain are examined microscopically for detection of undigested (direct test) or digested (indirect test) fats that appear as red-stained globules.

• Sudan grass [soo-dan′] Sorghum × drummondii.

• Sudanese Fulani cattle West African, lyre-horned, milking cattle, usually light gray.

• sudanophilia [soo-dan″o-fil′e- ] 1. affinity for a Sudan stain. 2. a condition in which the leukocytes contain particles staining readily with Sudan red III.

• sudanophilic [soo-dan″o-fil′ik] staining readily with Sudan III.

  • s. granules see sudanophilia (2).

• sudation [soo-da′sh n] the process of sweating.

• Sudax a Sudan grass hybrid with substantially less cyanogenetic glycoside content than the parent plant but still capable, in extreme circumstances, of causing cyanide poisoning.

• sudden death a category of illness in which animals that are under frequent observation die either with no obvious illness or after a period of illness lasting only a few hours. Typical causes are spontaneous internal hemorrhage, trauma causing shock or blood loss, rupture of the gut, cardiac tamponade, trauma to brain or spinal cord at the occipitoatlantal joint, intravenous injection of inappropriate solution, or given too rapidly causing cardiac arrest or pulmonary edema, anaphylactic shock. In large animals, examples are group deaths due to electrocution, lightning injury, many poisons especially cyanide, algal fast death factor, so-called Wimmera ryegrass poisoning, ingestion of Taxus sp., fluoroacetate, and oleander. Septicemia due to anthrax, toxemia due to Clostridium perfringens type D and colibacillosis can cause peracute deaths, but signs are evident in animals kept under surveillance. In feedlot cattle, sudden death can occur following the acclimatization phase of feeding and presents as death without premonitory signs of illness or agonal struggling. The cause is unknown. Postmortem examination shows no evidence of the common diseases that cause rapid death in feedlot cattle. In chickens, a syndrome of sudden death is recognized in broiler chickens. See acute death syndrome of chickens. Animals that are ‘found dead’ are in a different category to sudden death and have a much wider range of possible causes.

  • s. d. factors see anatoxin.

• sudomotor [soo″do-mo′t r] stimulating the sweat glands.

• sudor sweat; perspiration.

• sudoral characterized by profuse sweating.

• sudoresis [soo″do-re′sis] profuse sweating.

• sudoriferous [soo″do-rif′ r- s] 1. conveying sweat. 2. sudoriparous.

  • s. glands sweat glands.

• sudorific [soo″d -rif′ik] 1. promoting sweating; diaphoretic. 2. an agent that causes sweating.

• sudoriparous [soo″do-rip′ -r s] secreting or producing sweat.

• suet [soo′ t] hard, raw fat from a beef carcass sold for cooking. See also adipose renal capsule.

• sufentanil [soo-fen′t -nil] an opioid analgesic. An analog of fentanyl with 5–10 times the potency of fentanyl.

• suffocation [suf″ -ka′sh n] the stoppage of breathing, or the asphyxia that results from it. Suffocation can be caused by drowning, electric shock, gas or smoke poisoning, strangulation, or obstruction of the trachea by a foreign body.

• Suffolk horse a compact, neat, heavy English draft-horse. Chestnut only, 16–16.2 hands high, limbs almost devoid of feather. Called also Suffolk Punch.

• Suffolk Punch see Suffolk horse.

• Suffolk sheep an English Downs-type breed of short-woolled, meat sheep with a black, woolless head and distinctive Roman nose; polled, black legs. Genetic susceptibility to scrapie is more common in this breed than in other breeds. Origin of White Suffolk, South Suffolk.

• suffusion [s -fu′zh n] 1. the process of overspreading, or diffusion. 2. the condition of being moistened or permeated through.

• sugar [shoog′ r] 1. a simple carbohydrate such as a monosaccharide (e.g., glucose, fructose) or a disaccharide (e.g., sucrose) that dissolves in water. 2. a sweet carbohydrate of both animal and vegetable origin. Unless qualified, e.g., fruit sugar (fructose), milk sugar (lactose), usually refers to sucrose.

  • s. beet see Beta vulgaris.
  • s. beet pulp see beet pulp.
  • blood s. blood glucose.
  • s. caneSaccharum officinaruym, a grass in the plant family Poaceae; as such is not fed, but molasses and the pith, bagasse, are fed (Camola is a feed composed of 4 parts pith and 10 parts molasses). When infected by the fungus Arthrinium sp., can produce toxic nitro compounds. Sugar cane may contain sufficient cyanogenetic glycoside to cause poisoning if the appropriate enzyme is also supplied.
  • s. fecal centrifugation using Sheather’s solution; standard procedure for examination of feces for parasite eggs.
  • s. gum Eucalyptuscladoclayx.
  • invert s. a sugar obtained by hydrolyzing sucrose; a mixture of glucose and fructose. Called invert sugar because sucrose is dextrorotary—the mixture is levorotary. Used as a parenteral nutrient. Called also invertose.

    S-95.

    

    Suffolk meat sheep.

  • s. of lead lead acetate, used in the preparation of white lotion. Occurs naturally on weathered paintwork and is attractive and poisonous to animals.
  • s. of milk see lactose.

• sugillation [sug″jľ-la′sh n] ecchymosis.

• suicide substrate [soo′ľ-sīd] a compound that is not of itself toxic to a cell, but that resembles a normal metabolite closely enough that it undergoes metabolic transformation to a product that does inhibit a crucial enzyme, e.g., fluoroacetate. A substrate-analog that binds irreversibly to amino acids, usually the catalytic amino acid, thereby blocking the active site of the enzyme to other molecules and effectively ‘killing’ the enzyme.

• suid [soo′id] a member of the family Suidae of the order Artiodactyla; swine, includes the pigs, hogs or boars

• Suidasia nesbitti a grain mite in the family Acaridae that causes wheat pollard itch.

• Suidae the family of pigs; includes pigs (wild and domestic), hogs, bushpigs, warthogs, and babirusas.

• Suifilaria a genus of filarioid worms in the family Filariidae.

  • S. suis found in the intermuscular and subcutaneous connective tissue of pigs; causes no problems other than the physical presence of the worms in the meat.

• suiform pig-like.

• suint [swint] the water-soluble fraction of wool yolk.

• Suipoxvirus [soo′ľ-poks″vi′r s] a genus in the order Poxvirales, family Poxviridae. The cause of swinepox.

• suipoxvirus [soo′ľ-poks″vi′r s] a poxvirus in the genus Suipoxvirus, family Poxviridae.

• sulbactam [s l-bak′t m] an irreversible β-lactamase inhibitor that increases the activity of β-lactam antibiotics. Commonly used in combination with ampicillin and occasionally with cephalosporins.

• sulcate [sul′kāt] furrowed; marked with sulci.

• sulcular pertaining to a sulcus.

  • s. epithelium the epithelial lining of the gingival sulcus.
  • s. lavage rinsing of debris from the gingival sulcus. Usually part of professional dental cleaning.
• sulcus [sul′k s] pl. sulci [L.] a groove or furrow; a linear depression, especially one separating the gyri of the brain.

  • abomasal s. the third or abomasal part of the gastric groove.
  • alar s. lies between the dorsolateral cartilage at the nostril and the lateral accessory cartilage.
  • calcarine s. see calcarine sulcus.
  • central s. see Rolando’s fissure.
  • collateral s. see collateral fissure.
  • coronal s. a groove at the top of the hoof wall that houses the coronal matrix.
  • coronary s. an external groove that indicates the division between the ventricles of the heart and the atria. Houses the circumflex coronary blood vessels of the heart.
  • cruciate s. a deep groove that runs transversely across the rostro-dorsal surface of the cerebrum and that is one of the landmarks on the cerebral cortex.
  • s. cutis fine depressions of the skin between the ridges of the skin.
  • dorsal median s. see dorsal median fissure.
  • gingival s. the groove between the surface of the tooth and the epithelium lining the free gingiva.
  • hippocampal s. hippocampal fissure.
  • jugular s. see jugular furrow.
  • lateral cerebral s. see sylvian sulcus (below).
  • s. limitans a longitudinal groove in the neural tube wall of the embryo that is retained in the lateral wall of the fourth ventricle between the medial eminence and the rest of the rhomboid fossa.
  • omasal s. the second part of the gastric groove in ruminants.
  • reticular s. the first part of the gastric groove in ruminants.
  • rhinal s. a deep groove that separates the neopallium from the paleopallium on the lateral surface of the brain.
  • rumenoreticular s. a groove on the external surface of the forestomachs that marks the division between the rumen and reticulum.
  • scleral s. the groove between the sclera and cornea.
  • sylvian s. a landmark groove on the lateral side of the cerebral cortex extending laterally between the temporal and frontal lobes, and turning posteriorly between the temporal and parietal lobes. Called also fissure of Sylvius, lateral cerebral sulcus.
  • urethral s. the furrow in the ventral aspect of the corpus cavernosum of the penis that accommodates the corpus cavernosum urethrae and the urethra.

• sulfa drugs [sul′f ] a group of chemical compounds used as antibacterial agents; called also sulfonamides.

• sulfabenzamide [sul″f -ben′z -mīd] a sulfonamide antibiotic, similar to sulfamethoxazole.

• sulfabrom, sulfabromomethazine a derivative of the antimicrobial drug sulfamezathine that maintains blood concentrations for long periods, up to 48 hours in cattle.

• sulfachlorpyrazine [sul″f -klor″pir-id′ -zēn] an intermediate-acting sulfonamide, used as the soluble sodium salt in drinking water as a systemic antibacterial in chickens. It is absorbed rapidly from the gut.

• sulfachlorpyridazine a sulfonamide antibacterial remedy used in pigs and calves. It is most effective against gram-negative bacteria including Escherichia coli and Salmonella spp., but is limited in its usefulness because of its rapid absorption and excretion.

• sulfadiazine [sul″f -di′ -zēn] a rapidly absorbed and readily excreted sulfonamide antibacterial agent. The sodium salt is used intravenously.

  • silver s. the silver salt of sulfadiazine, having bactericidal activity against many gram-positive and gram-negative organisms, as well as being effective against yeasts; used as a topical anti-infective for the prevention and treatment of wound infections, including wound sepsis in patients with second, and third-degree burns.
  • sodium s. an antibacterial compound used intravenously.
  • s.–trimethoprim a popular potentiated ‘sulfa’ because of its broad antibacterial spectrum and its small dose rate.

• sulfadimethoxine [sul″f -di″m -thok′sēn] a long-acting sulfonamide antibiotic; derivative of sulfadiazine.

• sulfadimidine [sul″f -di′mľ-dēn] sulfamethazine.

• sulfadoxine [sul″f -dok′sēn] a long-acting sulfonamide antibiotic; called also sulformethoxine.

• sulfafurazole [sul″f -fu′r -zōl] a sulfonamide antibacterial compound used orally, topically and parenterally, in infections of the urinary and respiratory tracts and of soft tissues. Called also sulfisoxazole.

• sulfaguanidine the first sulfonamide antibiotic designed to treat enteric infections. It is poorly absorbed and retains high concentrations in the gut; a number of similar but superior drugs are now available.

• sulfallate a thiocarbamate herbicide that is poisonous if taken in large amounts. Not poisonous if used according to instructions. Causes muscle spasms, ataxia, depression, and, in chronic cases, alopecia. No longer used in the US. Called also CDEC.

• sulfamerazine [sul″f -mer′ -zēn] a short-acting sulfonamide antibiotic.

• sulfameter a long-acting sulfonamide antibiotic, used in urinary tract infections. Called also sulfamethoxydiazine.

• sulfamethazine [sul″f -meth′ -zēn] a sulfonamide antibiotic that is rapidly absorbed from the alimentary tract, slowly excreted, with minimal precipitation in renal tubules. Used orally as an antibacterial and coccidiostat agent; also vailable also as a soluble sodium salt for injection. Called also sulfadimidine, sulfamezathine.

• sulfamethizole [sul″f -meth′ľ-zōl] a short-acting sulfonamide antibio-tic used in urinary tract infections.

• sulfamethoxazole [sul″f -mth-ok′s -zōl] an antibacterial sulfonamide, especially useful in acute urinary tract infections and in infections of wounds and soft tissues. Commonly combined with trimethoprim and popularly known as trimethoprim-sulfa (TMPS), trim-sulfa, and SMZ.

• sulfamethoxydiazine sulfameter.

• sulfamethoxypyridazine a long-acting sulfonamide antibiotic that is rapidly absorbed but slowly excreted. Called also sulfapyridazine.

• sulfamezathine sulfamethazine.

• sulfamylon mafenide.

• sulfanilamide [sul″f -nil′ -mīd] a potent antibacterial compound, the first of the sulfonamides, and the drug that opened the door into the antibiotic era.

• sulfanilate [s l-fan′ľ-lāt] used in clinical pathology, determination of clearance from the blood with blood samples collected at timed intervals after the intravenous injection of sodium sulfanilate is a sensitive test of renal insufficiency, particularly reduced glomerular filtration.

• sulfapyridine [sul″f -pir′ľ-dēn] one of the very early sulfonamides but with significant toxicity. Now replaced by safer and more effective drugs.

• sulfaquinoxaline [sul″f -kwin-ok′s -lēn] a coccidiostat that was used extensively in chickens but has been largely superseded.

• sulfarsphenamine an organic arsenical that was once used as a systemic antibacterial agent but is now largely discarded.

• sulfasalazine [sul″f -sal′ -zēn] a combination of sulfapyridine and salicylic acid, used in the treatment and prophylaxis of idiopathic colitis and other inflammatory intestinal diseases. Previously called salicylazosulfapyridine.

• sulfasuxidine see succinylsulfathiazole.

• sulfatase an enzyme that catalyzes the hydrolysis of sulfate esters.

• sulfatases [sul′f -tās] enzymes that cleave sulfate esters from a wide range of substrates such as steroids, carbohydrates, proteoglycans, and glycolipids; one of the more than 50 groups of hydrolases responsible for the digestive properties and defensive functions of lysosomes.

• sulfate [sul′fāt] a salt of sulfuric acid.

  • s. conjugation an important in vivo mechanism for the detoxication of phenols and aliphatic alcohols.
  • high-s. diets associated with increased prevalence of polioencephalomalacia in ruminants.

• sulfathiazole [sul″f -thi′ -zōl] a short-acting sulfonamide antibiotic used as the phthalyl and succinyl forms for enteric infections. See also phthalylsulfathiazole and succinylsulfathiazole.

• sulfatide [sul′f -tīd] any of a class of cerebroside sulfuric esters. Called also sulfated galactocerebroside.

• sulfatroxazole a sulfonamide antibiotic.

• sulfhemoglobin [sulf″he-mo-glo′bin] a step in the pathway of degeneration of hemoglobin and the formation of Heinz bodies.

• sulfhemoglobinemia [sulf″he-mo-glo″bin-e′me- ] high concentration of sulfhemoglobin in the blood.

• sulfhydryl [s lf-hi′dr l] the univalent radical, −SH.

  • s. compounds compounds that contain sulfhydryl groups, principally the sulfur-containing amino acids. Used as radioprotective agents.

• sulfide [sul′fīd] any binary compound of sulfur; a compound of sulfur with another element or base.

• sulfiding superficial black pigmentation in meat carcasses, especially pigs, in which, either because of hot weather or a long period between slaughtering and dressing, there is time for interaction between hydrogen sulfide formed in the gut and hemoglobin in the blood vessels of the kidney and liver.

• sulfiram monosulfiram.

• sulfisoxazole [sul″f -sok′s -zōl] a sulfonamide antibacterial used orally, topically and parenterally, in infections of the urinary and respiratory tracts and of soft tissues. Called also sulfafurazole.

• sulfmethemoglobin [sulf″m t-he′mo-glo″bin] a compound of hemoglobin and hydrogen sulfide.

• sulfobromophthalein [sul″fo-bro″mo-thal′ēn] a sulfur- and brominecontaining compound previously used in liver function tests. The commercial name for the test reagent was Bromsulphalein.

  • s. clearance test a previously used test of liver function. The compound is injected intravenously, and measurement made at intervals of its serum concentration. Too slow a clearance is an indication of hepatic insufficiency. Called also BSP test.

• sulfonamide [s l-fon′ -mīd] 1. any compound containing the −SO₂NH₂ group. 2. any of a group of drugs that are derivatives of sulfanilamide, which competitively inhibit folic acid synthesis in microorganisms, and are bacteriostatic against gram-positive cocci (streptococci and pneumococci), gram-negative cocci (meningococci and gonococci), gram-negative bacilli (Escherichia coli and shigellae), and a wide variety of other bacteria. Called also sulfa drugs and outside the US, sulphonamides or sulpha drugs.

• sulfone [sul′fōn] a compound containing two hydrocarbon radicals attached to the −SO₂− group, especially dapsone (4,4′-sulfonylbisbenzenamine) and its derivatives, which are potent antibacterials effective against many gram-positive and gram-negative organisms.

• sulfonylurea [sul″f -nl-u-re′] a class of chemical compounds that includes the oral hypoglycemic agents acetohexamide, chlorpropamide, glipizide, glyburide, gliclazide, tolazamide, tolbutamide, and tolazamide.

• sulformethoxine sulfadoxine

• sulfosalicylic acid (SSA) test [sul″fo-sal″ľ-sil′ik] a turbidometric test for protein in the urine.

• sulfoxide [s l-fok′sīd] 1. the divalent radical =SO. 2. an organic compound intermediate between a sulfide and a sulfone.

• sulfur (S) [sul′f r] a chemical element, atomic number 16, atomic weight 32.064. Elemental sulfur is fed to animals to reduce their volume of feed intake, for example, in a feedlot using self-feeders. It is also fed as an oldfashioned worm prophylaxis and coccidiostat. Application of sulfur as a fertilizer to plants decreases their uptake of selenium and may predispose selenium deficiency in grazing livestock. High concentrations of sulfur in the diet are a cause of polioencephalomalacia in ruminants. Overfeeding of elemental sulfur causes enteritis characterized by black, evil smelling diarrhea. See also hydrogen sulfide poisoning.

  • s. dioxide a poisonous gas liberated by some industrial enterprises, e.g., copper smelting, from silage to which sodium metabisulfite has been added as a preservative and in old-fashioned treatments for mange. The gas causes irritation of the upper respiratory tract and pneumonia in severe cases. Commonly used as a meat preservative where it selectively destroys thiamine and has been incriminated as a cause of thiamine deficiency, particularly in dogs and cats.
  • s. granule small, soft to mineralized bodies in the pus of lesions of actinomycosis, actinobacillosis, and botryomycosis. Called also drusen. lime-s. see lime-sulfur.
  • s. myopathy skeletal and myocardial degeneration caused by the feeding of toxic concentrations of sulfur.
  • s. nutritional deficiency ruminants may need supplemental inorganic sulfur if the bulk of their nitrogen is not in the form of protein but as urea or ammonium phosphate. A deficiency in these circumstances causes anorexia, weight loss, poor digestion, and fall in milk yield.
  • precipitated s. a scabicide, antiparasitic, antifungal, and keratolytic. Called also milk of sulfur.
  • s. sublimatum, sublimed s. a parasiticide and scabicide. See also flowers of sulfur.
  • technetium coated s. colloid used in scintigraphy of the liver and reticuloendothelial systems. Called also ^99mTc sulfur colloid.

• sulfurated lime [sul′fu-rāt″ d] see lime-sulfur.

• sulfuric acid [s l-fūr′ik] an oily, highly caustic, poisonous compound, H₂SO₄.

• sulky horse-drawn, ultra-lightweight, single-seater, two-wheeled vehicle used by Standardbreds in races. Called also bike, gig.

• sulph- for words beginning thus, see also those beginning sulf-.

• sulphur sulfur.

• sumac [soo′mak] common name used for trees and shrubs, particularly Rhus spp., but also for Toxicondendron vernix (poison sumac).

• sumatrol one of the insecticidal substances, with rotenone, in derris.

• summation [s -ma′sh n] accumulate, add up, aggregate a series of numbers or quantities or events. In radiology, radiopacity created by superimposition of more than one structure.

  • s. of effects a theory explaining clinical pruritus as the additive effects of pruritus from several causes that may raise the individual above the threshold, but pruritus from any single cause would be unlikely to do so.
  • s. gallop see gallop rhythm.
  • neurological s. physiological summation in synapses is a characteristic of the mammalian nervous system. It may be spatial, with additional synaptic junctions participating, or temporal, when succeeding stimuli catch up with the as-yet undischarged neurotransmitter. Seen in the retina of the cat, as an example of a nocturnal animal, where many millions of photoreceptors are connected to only one million axons, resulting in maximal sensitivity to light.
  • weighted s. the sum obtained by adding the numerical value for individual clinical signs, each weighted to express their importance, when making a diagnosis. The total, as a fraction or a percentage, provides an estimate of the probability of each diagnosis being the correct one.

• summer slump associated with grazing endophyte infested Festuca arundinacea. Cattle have lower feed intake, depressed weight gains, depressed milk production, higher rates of respiration, elevated rectal temperature, and increased water consumption, a rough hair coat, reduced reproductive performance, and reduced prolactin concentrations in plasma. Has major occurrence in the US.

• summer kill term used to describe mortality among cultivated finfish caused by a higher water temperature than the particular species can tolerate, and/or the reduction in dissolved oxygen resulting from the elevated temperature.

• summer pasture associated recurrent airway obstruction noninfectious respiratory disease of horses at pasture during the summer in the Southeastern US. Characterized by limitations to airflow due to bronchoconstriction, excessive accumulation of mucus in the lower airways, and increased concentration of inflammatory cells in bronchoalveolar lavage fluid samples. See equine asthma syndrome.

• summit metabolism [sum′it] when heat losses from the animal’s body exceed its ability to produce metabolic heat.

• sump oil see crankcase oil.

• sump–Penrose drain a Shirley wound drain (sump drain) enclosed within a Penrose drain.

• sun conure a parrot in the family Psittacidae, native to northeastern South America. Also known as Sun Parakeek.

• sunburn [sun′b rn] inflammation—an actual burn—of the skin caused by exposure to ultraviolet rays of the sun as it occurs in humans does not occur in animals. White pigs suffer most and may develop a chronic dermatitis along the back, some may lose the tips of the ears by sloughing. Called also primary phototoxicity. Dogs and cats, particularly those with unpigmented skin on the dorsum of the nose, eyelids, ears, or groin, may develop a chronic actinic dermatitis. Fish in cultivation ponds show white patches on the top of the head and corneal cataracts. See also solar dermatitis.

  • s. cells dyskeratotic keratinocytes, either scattered or in a continuous band in the outer stratum spinosum, are characteristic of a sunburn lesion.

• sunburst appearance, effect description of a pattern of periosteal reaction in which thin spicules of irregular periosteal new bone radiate from a bone lesion. A feature of aggressive bone lesions such as neoplasia (e.g., osteosarcoma) and osteomyelitis.

• sundews see Drosera.

• sunflower (Helianthus annuus) a plant in the family Asteraceae whose seed is used for oil and for human food. The residual cake is a high-protein supplement but lacking in lysine. Decorticated seed cake contains 44% protein, undecorticated seed cake, suitable only for ruminants because it contains the seed hulls, contains 28% protein. Leaves and stems can contain toxic amounts of nitrate and cause nitrate-nitrite poisoning in ruminants.

  • wild s. see Doronicum hungaricum, Verbesina encelioides, Wedelia asperrima.

• sunlight the actinic rays of direct sunlight are known to have disinfectant properties, to be instrumental in the production of vitamin D in the skin and to be the trigger mechanism in photosensitive dermatitis, squamous cell carcinoma of the eye, nose, and genitals of multiple species, and solar dermatitis.

• sunscreen [sun′skrēn] a topical agent that filters ultraviolet rays reaching the skin; used to prevent sunburn, actinic dermatitis (photosensitization), squamous cell carcinoma in unpigmented skin, and in the control of discoid lupus erythematosus.

• Sunshinevirus a genus in the family Sunviridae, order Mononegavirales, distantly related to the genus Ferlavirus. Associated with neurorespiratory disease and fatalities in snakes, mostly pythons.

• sunstroke [sun′strōk] causing damage to the central nervous system by penetration of tissues by actinic rays. See heat¹ exhaustion and heat¹ stroke.

• super- word element. [L.] above, excessive.

• superalimentation [soo″p r-al″ľ-mn-ta′sh n] excessive feeding; sometimes used in the treatment of wasting diseases.

• superalkalinity [soo″p r-al″k -lin′ľ-te] excessive alkalinity.

• superantigen [soo″p r-an′tľ-j n] molecules that are potent T lymphocyte mitogens that act by simultaneously binding directly to class II MHC molecules and to conserved regions of the T-cell receptor. They are often associated with staphylococcal products and are involved in enterotoxemias and toxic shock syndrome in humans.

• superbug a colloquial reference to a bacterium that carries resistance genes to many antibiotics or to a bacterium or virus of greatly enhanced virulence.

• superfamily [soo″p r-fam′ľ-le] 1. a group of proteins related in structure but different in function, e.g., immunoglobulin superfamily that includes immunoglobulins, T cell receptor, major histocompatibility class I and II, β₂-microglobulin, α/β glycoprotein, neuronal cell-adhesive molecule (NCAM), neurocytoplasmic protein 3 (NP3), and others. 2. a taxonomic hierarchy, a rank of organisms, above that of family, but below suborder.

• superfecundation [soo″p r-fe″kn-da′sh n] fertilization of two or more ova during the same ovulatory cycle, by separate coital acts.

• superfetation [soo″p r-fe-ta′sh n] the fertilization and subsequent development of an ovum when a fetus is already present in the uterus, a result of fertilization of ova during different ovulatory cycles and yielding fetuses of different ages.

• superficial [soo″p r-fish′ l] situated on or near the surface.

• superficialis [soo″p r-fish″e-a′lis] superficial.

• superficies [soo″p r-fish′e-ēz] an outer surface.

• superfine a class of Merino sheep with wool finer than that of fine-wool. Usual limit is wool of 18.5 microns or less fiber diameter.

• superhutches calf housing structures, often open on one side, designed for a small number of calves when first grouped immediately after weaning. See also hutch (2)

• superinduce [soo″p r-in- ′] to bring on in addition to an already existing condition.

• superinfection [soo″p r-in-fek′sh n] a new infection complicating the course of antimicrobial therapy of an existing infection, due to proliferation of bacteria or fungi, usually part of the normal flora, resistant to the drug(s) in use and capable of occupying the niche vacated by organisms susceptible to the drug.

• superinvolution [soo″p r-in″vo-loo′sh n] prolonged involution of the uterus after delivery, to a size much smaller than the normal, occurring in females that are still suckling their young.

• superior [soo-pēr′e- r] 1. situated above, or directed upward. 2. located toward the head in bipeds.

• superjacent [soo″p r-ja′s nt] located just above.

• superjuice Australian farmers’ remedy for almost everything; saturated solution of superphosphate prepared by soaking enough of the fertilizer in a large drum of water to ensure that there is always a residue. A cupful per cow per day wards off nutritional deficiency of phosphorus.

• superlactation [soo″p r-lak-ta′sh n] oversecretion of milk; hyperlactation.

• superlethal [soo″p r-le′th l] more than sufficient to cause death.

• supermotility [soo″p r-mo-til′ľ-te] excessive motility.

• supernatant [soo″p r-na′t nt] the liquid lying above a layer of precipitated insoluble material.

• supernumerary [soo″p r-noo′m r-ar″e] in excess of the regular number.

• supernutrition [soo″p r-noo-trľ′sh n] see superalimentation.

• superolateral [soo″p r-o-lat′r- l] above and to the side.

• superovulation [soo″p r-ov″u-la′sh n] production of more than one ovum at ovulation. 1. Planned production of a number of ova from the one cow at the same ovulation period is an essential part of the technique of bovine embryo transfer. Can be effected with a single injection of PMSG or for better results, with FSH and LH in a 5:1 ratio, twice daily for 5 days. Called also multiple ovulation or ovarian superstimulation. 2. Can occur accidentally when cows are treated with large doses of FSH as a treatment for no visible estrus.

• superoxide [soo″p r-ok′sīd] any compound containing the highly reactive superoxide ion O₂ ⁻, a common intermediate in numerous biological oxidations and an important killing mechanism generated in lysosomes of phagocytes after they have phagocytosed microorganisms.

  • s. dismutase an enzyme that converts peroxides to two kinds of molecules in different states of oxidation. Predominantly present in aerobic and facultatively anaerobic bacteria.

• superphosphate the common fertilizer for the application of phosphorus to a deficient soil. Used also to provide a direct nutritional supplement, as super-juice, the supernatant from a settled mixture of superphosphate and water. Fluorine poisoning may occur in animals with access to superphosphate made from rock phosphate with a high fluorine content.

• superpurgation [soo″p r-pr-ga′sh n] violent, watery diarrhea.

• supersaturate [soo″p r-sach′ r-āt] to dissolve more of an ingredient in a solvent than can be held in solution under normal circumstances.

• superscription [soo″p r-skrip′sh n] something written above; the first of four chief parts of a drug prescription, the prescription sign (for recipe, [L.] “take”).

• superseding taking over a case of a patient under treatment by another veterinarian. In general terms, this is poor professional etiquette unless the other veterinarian has been consulted and agrees to the change. However, there are many situations in which professional etiquette is overridden by the need to provide the best treatment for the animal.

• superstimulation see superovulation.

• supertension extreme tension or strain.

• supervascularization [soo″p r-vas″ku-lr-ľ-za′sh n] in radiotherapy, the relative increase in vascularity that occurs when tumor cells are destroyed so that the remaining tumor cells are better supplied by the (uninjured) capillary stroma.

• supervision oversight; direction. In the context of teacher–student, the observing and directing of learning activities, usually of a practical nature. In the case of management of clinical cases, the responsibility for all that is done for the patient.

  • direct s. licensed veterinarian is readily available on the premises where the patient is being treated.
  • indirect s. veterinarian has given either written or oral instructions for treatment of the patient and is readily available by telephone or other form of communication.

• supervoltage in radiation therapy, pertaining to x-rays produced by a tube voltage in the range of 500–1000 kilovolts.

• supination [soo″pľ-na′sh n] in humans, rotation of the forearm to bring the palm to face upward; in animals, the action is best accomplished in primates but is still significant in laboratory animals, cats and dogs, where the range of supination is reduced to around 90°, as for example with a squirrel holding a nut, or a cat a ball of wool or a dog a bone.

• supplejack see Ventilago viminalis.

• supplementary in addition to the already supplied basics.

• supplementation the provision of supplementary materials.

• supplements an ingredient intended to supply additional nutritional value to the diet. These include such things as vitamins, minerals, amino acids, and herbs that are marketed in forms such as feed additives, tablets, liquids, capsules, gelcaps, and powders. Supplements cannot be marketed for treating, preventing, or curing disease. See also feed supplements.

  • liquid s. molasses-based supplement that contains a nonprotein nitrogen such as urea. Often also contains minerals and other feed additives.

• suppository [s -poz′ľ-tor-e] an easily fusible medicated mass for introduction into the rectum, urethra or vagina.

• suppressant [s -pres′ nt] 1. inducing suppression. 2. an agent that stops secretion, excretion or normal discharge.

• suppression [s -presh′ n] 1. sudden stoppage of a secretion, excretion or normal discharge. 2. in genetics, restoration of a lost function by a second mutation either in a gene other than that involved in the primary mutation, or within the same gene.

• suppressor cells [s -pres′ r] see T lymphocyte.

• suppurant [sup′u-r nt] 1. promoting suppuration. 2. an agent causing suppuration.

• suppurate produce pus.

• suppuration [sup″u-ra′sh n] formation or discharge of pus.

  • lamellar s. see lamellar suppuration.

• suppurative [sup′u-ra″tiv] pertaining to or emanating from suppuration; pus in e.g., suppurative arthritis, bronchopneumonia.

• supra- word element. [L.] above or over.

• supra-acromial [soo″pr --kro′me- l] above the acromion.

• supra-auricular [soo″pr -aw-rik′u-l r] above the ear.

• supracaudal organ, gland [soo″pr -kaw′d l] see tail gland.

• suprachoroid [soo″pr -kor′oid] above or upon the choroid.

  • s. layer most superficial of the five laminae constituting the choroid; the layer is avascular and composed of collagen fibers, chromatophores, macrophages, fibroblasts.

• suprachoroidea the outermost layer of the choroid.

• supracondylar [soo″pr -kon′d-l r] above a condyle.

• supracostal [soo″pr -kos′t l] above or outside the ribs.

• supracotyloid [soo″pr -kot′ -loid] above the acetabulum.

• supradiaphragmatic [soo″pr -di″ -frag-mat′ik] cranial to the diaphragm.

• supraduction [soo″pr -duk′sh n] the turning upward of a part, especially the eyes.

• supraepicondylar [soo″pr -ep″ľ-kon′d-l r] above the epicondyle.

• supragingival [soo″pr -jin′jľ-v l] a position on the tooth located coronal to the gingival margin.

• supraglenoid [soo″pr -gle′noid] above the glenoid cavity.

• suprahyoid [soo″pr -hi′oid] above the hyoid bone.

• supraliminal [soo″pr -lim′ľ-n l] above the threshold of sensation.

• supralumbar [soo″pr -lum′bahr] above the loin or lumbar region.

• supramaxillary [soo″pr -mak′sľ-lar″e] pertaining to the upper jaw.

• supraorbital [soo″pr -or′bľ-t l] above the orbit.

  • s. foramen see supraorbital foramen.
  • s. nerve block see supraorbital block.

• suprapelvic [soo″pr -pel′vik] above the pelvis.

• suprapharmacological an amount much greater than the usual therapeutic dose or pharmacological concentration of a drug.

• suprapharyngeal diverticulumimpaction [soo″pr -f-rin′je- l] impaction of the sac in pigs fed indigestible roughage causes pharyngeal obstruction and difficulty in swallowing.

• suprapontine [soo″pr -pon′tīn] above or in the upper part of the pons.

• suprapubic [soo″pr -pu′bik] cranial to the pubes; prepubic.

• suprarenal [soo″pr -re′n l] above a kidney; adrenal.

  • s. gland adrenal gland.

• suprarenalectomy [soo″pr -re″nl-ek′t -me] adrenalectomy; excision of one or both adrenal glands.

• suprascapular [soo″pr -skap′u-l r] above or superficial to the scapula.

  • s. neuropathy lesion in the suprascapular nerve leading to paralysis and atrophy of the supraspinatus, triceps, and the infraspinatus muscles.
• Sweeney shoulder in horses.

  • s. paralysis paralysis of the suprascapular nerve that leads to atrophy of the supraspinatus and infraspinatus muscles; usually due to trauma. Called also slipped shoulder, sweeney, equine suprascapular neuropathy.

• suprascleral [soo″pr -sklēr′ l] on the outer surface of the sclera.

• suprasellar [soo″pr -sel′ r] above the sella turcica.

• supraspinal [soo″pr -spi′n l] above the spine.

• supraspinatus above or cranial to the spine of the scapula.

• suprasternal [soo″pr -ster′n l] above the sternum.

• supratrochlear [soo″pr -trok′le- r] above the trochlea.

• supravaginal [soo″pr -vaj′ľ-n l] outside or above a sheath, specifically, above the vagina.

• supravalvular [soo″pr -val′v r] above the heart valves.

  • s. aortic stenosis see aortic stenosis.
  • s. stenosis one of the forms of congenital constriction of the pulmonary trunk.

• supraventricular [soo″pr -vn-trik′u-l r] situated or occurring above the ventricles, especially in an atrium or atrioventricular node.

• supraversion [soo″pr -ver′zh n] a malocclusion where a tooth extends farther than normal in an occlusal direction; frequently seen in canine teeth of domestic cats where the condition has been called abnormal tooth extrusion.

• supravital stain [soo″pr -vi′t l] see supravital stain.

• suramin [soo′r -min] a trypanocidal agent that is also toxic to the host animal, causing degeneration of the liver, kidney, and adrenal glands. Mode of action unknown. It is also an inhibitor of reverse transcriptase, some types of growth factors, and causes suppression of the adrenal cortex, leading to investigations of its usefulness in the treatment of immunodeficiency infection in humans and cats, cancer, and hyperadrenocorticism.

• surcingle a separate, wide, thin strap or webbing passed around the horse and including the saddle and buckled tight underneath.

• surditas deafness.

• surface [sur′f s] the outer part or external aspect of a body.

  • s.-active agent any substance capable of altering the physicochemical nature of surfaces and interfaces; an example is a detergent. Called also surfactant.
  • s. area conversion chart see Table 19.
  • s. body weight see body surface area.
  • s. catalysis in the intrinsic coagulation pathway, conversion of factor XII into its active state, factor XIIa, is catalyzed by contact with glass or a similar surface.
  • s. contact plates a bacteriological preparation in which the agar surface is slightly higher than the rim of the plate and inoculation is by inversion and direct contact with the surface being sampled.

• surfactant [s r-fak′t nt] a surface-active agent, such as soap or a synthetic detergent. In pulmonary physiology, a mixture of phospholipids (mainly dipalmitoylphosphatidylcholine) secreted by the great, or type II, alveolar cells into the alveoli and respiratory air passages, which reduces the surface tension of pulmonary fluids and thus contributes to the elastic properties of pulmonary tissue. See also hyaline membrane disease.

• surgeon [sur′j n] a veterinarian who practices in surgery. In many countries, it is still the practice to continue the British tradition of having all veterinarians call themselves veterinary surgeon and for the registering legislation to be the Veterinary Surgeon’s Act.

• surgeon’s knot same as a square knot except that the first throw is a double one. It is more secure than a square and holds its position better under conditions of wound tension for the second throw. It is often reinforced by a third or fourth single throw. See also knot.

• surgery [sur′j r-e] 1. that branch of veterinary science that treats diseases, injuries, and deformities by manual or operative methods. See also veterinary surgery. 2. the place in a hospital, or doctor’s or dentist’s office where surgery is performed. 3. in some countries a room or office where a veterinarian sees and treats patients. 4. the work performed by a surgeon.

  • basic s. kit the collection of instruments, wrapped, sterilized, and ready for use in the majority of uncomplicated surgical procedures. The choice of instruments may vary from one surgeon to another, but generally there are tissue forceps, thumb forceps, sponge forceps, hemostats, towel clamps, scalpel handle, and needle holder. Scissors and needles may be added after cold sterilization.
  • bench s. surgery performed on an organ that has been removed from the body, after which it is reimplanted.
  • cold steel s. that performed with traditional cutting instruments; to distinguish from cryosurgical and electrosurgical methods.
  • cosmetic s. performed to improve the appearance, or change the appearance, of the animal; surgery that is not necessary for the health of the animal. Other than ear cropping and tail docking, where performed, generally discouraged or considered unethical for animals as it is usually done for purposes of improving their appearance in the show ring or to disguise traits that might be heritable.
  • elective s. surgery carried out at a time convenient to client and surgeon. The opposite of emergency surgery. Distinctly different to cosmetic surgery.
  • emergency s. to treat trauma or acute illness subsequent to an emergency presentation.
  • experimental s. that carried out as part of a planned experimental protocol, usually on animals selected specifically for the purpose and that are often sacrificed afterward. Increasingly, use of animals in this way is under the control of institutional or governmental authorities.
  • plastic s. that concerned with the restoration, reconstruction, correction, or improvement in the shape and appearance of body structures that are defective, damaged, or misshapen by injury, disease, or anomalous growth and development.
  • replacement s. transplanting of tissues or organs from another host. Not commonly undertaken in veterinary surgery.
• surgical [sur′jľ-k l] emanating from or pertaining to surgery.

  • s. abdomen see acute abdomen.
  • s. cap an accompaniment to the surgical gown and mask that covers the head, and sometimes facial hair, of members of the surgical team; the object is to avoid contamination of the wound.
  • s. fever resulting from extensive tissue damage in major surgery.
  • s. gown sterile outer clothing worn by a surgeon to decrease the contamination of surgical wounds during surgery from the surgeon’s skin and clothing. Made from synthetic disposable (single use) material or reusable cotton fabric that can be re-sterilized.
  • s. gut see catgut.
  • s. insemination carried out by gaining access to the uterus by surgical means including per vaginam and via laparotomy or laparoscopy.
  • s. instruments a group of instruments used in the performance of surgical operations. Nowadays there are subdivisions including ophthalmic, orthopedic, vascular, gut, thoracic, and obstetric surgery.
  • s. mask a protective covering over the mouth and nostrils of members of a surgical team, usually held in place by tapes tied over or behind the head, intended to minimize wound contamination.
  • s. needle see needle.
  • s. pins see pinning.
  • s. scissors see standard surgical scissors.
  • s. shock shock occurring as a result of massive or traumatic surgery. To a large extent the term is a contradiction because one of the principal objectives of surgery is the avoidance of shock but there are occasions, e.g., in a major resection of the gut in a horse or a cesarean in a mare, when extensive handling of heavy viscera is unavoidable, and shock must be considered as inevitable unless preventive therapy is provided.
  • sterile s. pack all of the instruments and other equipment such as drapes, gloves, etc., required for a particular operation, or part of an operation, specially arranged, wrapped, and sterilized by autoclaving then stored for future use.
  • s. suite a group of rooms designed to provide all surgical services to patients. Includes surgery, preparation, and anesthesia for the patient, sterile preparation of the surgeon, instrument and materials sterilization and storage, instrument cleaning, and recovery room.

• Suri a breed of alpaca characterized by silky locks that hang loosely from the body. See Huacaya

• surra [soor′ ] the disease occurring principally in camels and horses, caused by Trypanosoma evansi and transmitted by biting flies. The clinical syndrome includes intermittent fever, anemia, and weight loss and a high case fatality rate. See also nagana.

• surrogate [sur′o-g t] a substitute; a thing or animal that takes the place of something or some animal, as a drug used in place of another, or, in animal husbandry, an animal that takes the place of another in the family or herd environment.

• sursumduction [sur″s m-duk′sh n] the turning upward of a part, especially the eyes.

• Surti a domestic Indian breed of black or brown buffalo with two white collars; used for dairying and draft.

• surveillance [s r-vāl′ ns] keeping a watch over.

  • active s. sampling, including necropsy examination, of clinically normal samples of the population; important in the surveillance of diseases in which subclinical cases and carriers predominate.
  • epidemiological s. watching over a population and recording data likely to have epidemiological significance, usually with the aim of early detection of disease. Essentially an interventionist exercise compared with monitoring, which is passive.
  • passive s. examination of only clinically affected cases of specified diseases in the population.

• survey a comprehensive examination of an area or population for a particular purpose. The survey may be of a part, e.g., cross-sectional survey, or for a particular end-result, e.g., a prevalence survey, or by the use of a particular method, e.g., aerial survey, or a combination of these, e.g., seroepidemiological.

  S-96.

  

  Basic components of a surgical instrument.

  • s. radiograph a plain radiograph performed prior to contrast radiography.

• survivorship rate proportion of the population that are still alive at successive annual ages.

• Sus a genus of pigs, including the domestic pig (S. domestica or S. scrofa domesticus), bearded pig (S. barbatus), and wild boar (S. scrofa).

• susceptibility [s -sep″tľ-bil′ľ-te] the state of being susceptible. Refers usually to infectious disease but may be to physical factors such as wetting or to psychological factors such as harassment. Signs that suggest a state of increased susceptibility to infection are: infections in the first few weeks of life, repeated bouts of infection, infections with nonvirulent pathogens, attacks of illness after vaccination with attenuated vaccines, and low leukocyte counts. See also immune deficiency disease.

  • antimicrobial s. diagnostic test results indicating likelihood of a cultured pathogen to be inhibited or killed by a specific antimicrobial agents, usually antibiotics

• susceptible [s -sep′tľ-b l] readily affected or acted upon; lacking immunity or resistance.

• suscitate to arouse to greater activity.

• suscitation an arousal to greater activity.

• suspension [s s-pen′sh n] 1. temporary cessation, as of pain or a vital process. 2. a supporting from above, as in treatment of spinal disorders. 3. a preparation of a finely divided, undissolved substance dispersed in a liquid vehicle.

  • colloid s. see colloid.

• suspensoid [s s-pen′soid] a colloid system in which the disperse phase consists of particles of any insoluble substance, such as a metal, and the dispersion medium may be gaseous, liquid or solid.

• suspensory [s s-pen′sor-e] serving to hold up a part, such as a ligament, bone, or muscle; a sling for supporting a part.

  • s. ligament 1. the modified interosseous muscle of the horse that arises from the palmar carpal ligament behind the knee (or the hock in the hindlimb) and suspends the pair of sesamoid bones behind the fetlock. The distal continuation of the ligament is composed of the cruciate, oblique, and straight sesamoidian ligaments and the pair of extensor branches that unite with the common digital extensor tendon. 2. any ligament that acts to suspend a body part.
  • s. ligament of the lens delicate ligament suspending the lens from the ciliary body of the eye.
  • ovarian s. ligament a peritoneal fold that forms the cranial limit to the mesovarium.
  • rupture of udder s. ligament the medial attachment separates, the udder floor drops down and outward so that the teats point laterally. The cow is difficult to milk, especially with a machine.

• Sussex a solid red breed of beef cattle similar to the Devon. There are horned and polled breeds.

• Sussex spaniel a massive, strongly built dog with short, well-boned legs. It has a broad head, round, deep, and wide chest, pendulous ears, and a distinctive golden liver-colored coat that is abundant and flat with feathering on the legs, ears, and lower body. The tail may be docked to a medium length. The breed has a characteristic rolling gait. Identified as a Vulnerable Native Breed by the Kennel Club UK.

• sustained-release preparations formulations of medicines that limit their solubility so that they are delivered at a slow but steady rate into the blood supply. Includes oral preparations in the form of reticular bullets of metal or ceramic and slow-release granules, intramuscular injection of slowly soluble substances, e.g., procaine penicillin, or drugs suspended in oil or in tablets, usually deposited under the skin. Microsyringes, described as osmotic pumps, are also being used for the pulsatile delivery of hormones over a long period.

  • s.-r. p. for bloat control capsules containing anti-foaming agents or ionophores are administered by mouth.
• sustentacular [sus″t n-tak′u-l r] supporting; sustaining.

  • s. cell a supporting epithelial cell that lacks a specialist function.
• sustentaculum [sus″t n-tak′u-l m] pl. sustentaculi [L.] a support.

  • s. tali a medial process of the calcaneus, extending over the plantar aspect of the talus.

• susurrus [L.] murmur. Especially a rustling sound.

• sutilains [soo′tľ-lāns] proteolytic enzymes derived from a strain of Bacillus subtilis used for wound débridement.

• sutura [soo-tu′r ] pl. suturae [L.] suture; used in anatomical nomenclature to designate a type of joint in which the apposed bony surfaces are united by fibrous tissue, permitting little or no movement; found only between bones of the skull.

  • s. lambdoides see lambdoid suture.
  • s. sagittalis see sagittal suture.

• suturation [soo″ch -ra′sh n] the process or act of suturing.

• suture [soo′ch r] 1. the line of union of adjoining bones of the skull. See also sutura. 2. the linear union of the crystalline lens fibers at the anterior and posterior poles at all levels within the lens. May be the location of cataracts. 3. a stitch or series of stitches made to secure apposition of the edges of a surgical or traumatic wound; used also as a verb to indicate application of such stitches. 4. material used in closing a wound with stitches.

  • absorbable s. (4) a strand of organic or synthetic material used for closing wounds, which becomes dissolved in the body fluids and disappears, such as catgut and tendon or polydioxanone.
  • anchoring s. (3) the fixation of adjacent tissues by means of a suture.
  • apposition s. (3) a superficial suture used for exact approximation of the cutaneous edges of a wound.
  • approximation s. (3) a deep suture for securing apposition of the deep tissue of a wound.
  • automatic ridge s. (3) see mattress suture pattern.
  • biocidal s. (4) impregnated with a biocidal material.
  • braided s. (4) thin filaments braided into a single suture; has the virtues of strength, flexibility, ease of handling, and good knot security.
  • Bunnell s. (3) see Bunnell suture pattern.

    S-97.

    

    Sutures between the bones of a puppy’s skull. 1, Parietal bone; 2, frontal bone; 3, fontanelle (fonticulus); 4, orbit.

  • buried s. (3) one placed deep in the tissues and concealed by the skin.
  • button s. (3) a mattress suture that includes a button on either side of the wound to prevent cutting of the wound by the suture.
  • Caslick s. (3) see Caslick operation.
  • catgut s. (4) see catgut.
  • Chinese finger cuff s. (3) a method of securing a thoracostomy tube to the thoracic wall in which the suture is placed deeply into the skin and underlying tissue, and the ends are wrapped around the protruding tube in a spiral pattern (‘Chinese finger cuff’) and tied.
  • circular s. (3) one applied around the circumference of a hollow viscus to close it, or to a portion of the wall to bring about inversion of the wall.
  • cobbler’s s. (3) one made with suture material threaded through a needle at each end.
  • Connell s. (3) see Connell suture pattern.
  • continuous s. (3) one in which a continuous, uninterrupted length of material is used. Called also whip stitch.
  • continuous lock s. (3) see lock-stitch suture pattern.
  • coronal s. (1) the line of union between the frontal bone and the parietal bones.
  • cotton s. (4) a multifilament suture used mainly for closure of skin.
  • cranial s. (1) the lines of junction between the bones of the skull.
  • cruciate s. (3) see cruciate suture pattern.
  • Cushing s. (3) see Cushing suture pattern.
  • Czerny s. (3) see Czerny suture.
  • Czerny–Lembert s. (3) see Czerny–Lembert suture.
  • false s. (1) a line of junction between apposed surfaces without a serrated union of the bones.
  • far–near–far s. (3) see near–far–far–near suture pattern.
  • far–near–near–far s. (3) used on tendons, the first bite is made farthest from the severed end, across the gap, and emerging close to the severed edge of the distal end. The second bite is close to the end of the proximal segment, crosses the gap, and emerges farther from the end of the distal segment. See also tendon suture (below).
  • figure-eight s. (3) a row of surgical pins are placed through both edges of the wound, and suture material is wound back and forth around each pin, as with a shoelace.
  • four stitch interrupted s. (3) see mattress suture pattern.
  • furrier’s s. (3) simple continuous suture.
  • Gambee s. (3) see Gambee suture pattern.
  • Gély’s s. (3) see Gély’s suture pattern.
  • Goetze’s s. (3) see Goetze’s suture pattern.
  • Halsted s. (3) see Halsted suture pattern.
  • horizontal mattress s. (3) an everting suture pattern. See mattress suture pattern.
  • interrupted s. (3) one in which each stitch is made with a separate piece of material.
  • intradermal s. (3) one placed in the lower dermis; a buried suture. May be interrupted or continuous.
  • intracutaneous s. (3) one totally within the substance of the skin, not emerging externally and not into the subcutaneous tissues. See also intradermal suture (above).
  • inverting s. (3) one that turns the edges of the incision inward so the exposed surfaces, usually serosa, contact each other, and the edges of the incision are buried. Used in closure of hollow viscera such as the stomach, uterus, intestine, or visceral stumps. Includes the Connell, Cushing, Halsted, Lembert, and Parker–Kerr suture patterns.
  • Kessler s. (3) see locking-loop suture (below).
  • lambdoid s. (1) the line of union between the upper borders of the occipital and parietal bones, shaped like the Greek letter lambda; called also sutura lambdoides.
  • Lembert s. (3) see Lembert suture pattern.
  • locking-loop s. (3) a tension suture used for apposition of severed tendon ends.
  • McLean s. (3) a mattress-type corneoscleroconjunctival suture.
  • mattress s. (3) see mattress suture pattern.
  • Mersilene s. (4) an uncoated polyester suture material.
  • metal s. (4) stainless steel is used universally. There are also special metal devices including Michel clips and skin staples and staples for intestinal repair.
  • near–far–far–near s. (3) see near–far–far–near suture pattern.
  • nonabsorbable s. (4) includes silk, steel, polyester, polymerized caprolactam, polypropylene, polyethylene, nylon, and cotton.
  • nylon s. (4) may be braided or monofilament.
  • Parker–Kerr s. (3) see Parker–Kerr suture pattern.
  • s. pattern (3) the placement of suture material, usually designed to achieve a particular purpose in relation to the tissue, organ or surgical procedure being performed, e.g., inversion or eversion of wound edges, relief of tension on the wound, or cosmetic results.
  • s. pin (4) sharp-pointed pins that can be pushed through tissue, e.g., vulval lips, and secured at both ends by knobs so that they stay in situ.
  • polyester s. (4) a multifilament strand, Dacron impregnated or coated with Teflon, silicone, or polybutilate used as nonabsorbable sutures. Their virtue is their strength, their disadvantage the difficulty encountered in tying a knot that holds.
  • pull-out s. (3) see pull-out suture pattern.
  • purse-string s. (3) a type of suture commonly used to bury the stump of the appendix, a continuous running suture being placed about the opening, and then drawn tight.
  • relaxation s. (3) any suture so formed that it may be loosened to relieve tension as necessary.
  • retention s. (3) used in the replacement of vaginal and uterine prolapse in cattle. Usually thick, heavy suture material, sometimes tape, is placed through adjacent tissues.
  • round-wound s. (3) used for tension relief, it consists of surgical pins placed through both sides of the wound and suture material wound around the protruding ends and across the incision.
  • safety s. (3) used in the surgical correction of patent ductus arteriosus, particularly in small dogs, to ensure that any slippage of ligatures or tissue will not result in excessive blood loss before being controlled by other means.
  • sagittal s. (1) the line of union of the two parietal bones, dividing the skull anteroposteriorly into two symmetrical halves; called also sutura sagittalis.
  • silk s. (4) braided silk is used as a nonabsorbable suture. It may be coated with wax or silicone to reduce its absorption of fluids. Its great advantages are its ease of handling and good knot-holding quality.
  • squamous s. (1) a suture where the uniting bones overlap such as the suture between the pars squamosa of the temporal bone and parietal bone.
  • stainless steel s. (4) see wire suture (below).

    S-98.

    

    Types of suture patterns: (A) simple continuous, (B) simple interrupted, and (C) cruciate suture.

  • stent s. (3) a tension suture for closing wounds created by placing a roll of bandage along the line of incision and tying the sutures over the top of it.
  • subcuticular s. (3), subcutaneous s. a method of skin closure involving placement of stitches in the subcuticular tissues parallel with the line of the wound.
  • tendon s. (3) see Bunnell suture pattern, far-near-near-far suture (above), three-loop pulley suture (below).
  • tension s. (3) one placed to relieve tension on the incision; may be the same suture pattern that closes the incision or a separate suture or line of sutures of a different pattern.
  • three-loop pulley s. (3) a complicated suture pattern used on tendons. See tendon suture (above).
  • U-s. (3) see mattress suture pattern.
  • vertical mattress s. an everting suture pattern. See mattress suture pattern.
  • vest-over-pants s. (3) see vest-over-pants suture pattern.
  • walking s. (3) a pattern of interrupted sutures used in closing large skin wounds. Each suture is placed first in the deep dermis and then into the deeper tissues, usually fascia, at a point closer to the center of the wound. The effect is to move the skin closer to the closing position with each suture, obliterate dead space, and relieve tension on the sutures eventually placed to close the wound edges.
  • wire s. (4) stainless steel wire used as suture material as monofilament or braided. Problems are kinking, bulk knots, tearing of tissues, and the need for special cutting instruments.
  • Zimmerman’s aluminum wire s. (3) a technique used for tension support. The stitches are placed with a cannula, and ends are rolled instead of being tied.

• suture knot may be tied manually or by instrument in several patterns. See also square knot, surgeon’s knot.

• suxamethonium [suk″s -m-tho′ne- m] see succinylcholine.

• Sv sievert.

• SV-5 virus simian virus type 5; see Parainfluenzavirus 2.

• SVD swine vesicular disease.

• SVE special visceral efferent.

• Svedberg (S) a unit used to express sedimentation coefficients.

• swab [swahb] 1. a small pledget of cotton or gauze wrapped around the end of a slender wooden stick or wire for applying medications or obtaining specimens of secretions, etc., from body surfaces or orifices. 2. use of a swab to collect a specimen, e.g., collection of a sample of saliva for testing horses for doping.

• swage [swāj] 1. to shape metal by hammering or by adapting it to a die. 2. to fuse, as suture material to the end of a suture needle.

• Swainsona [swān′s -n] Australian genus of plants in the legume family Fabaceae, closely related to Astragalus; contain the toxic indolizidine alkaloid swainsonine that causes tremor, incoordination, mania, and death from an acquired lysosomal storage disease through inhibition of α-mannosidase so that mannose accumulates in nervous and other tissues. Toxic species include S. brachycarpa (small-flowered Darling pea), S. canescens (gray Swainson pea), S. galegifolia (smooth Darling pea), S. greyana (Darling pea), S. luteola (dwarf Darling pea), S. procumbens (Broughton pea), S. swainsonioides. See also mannosidosis, Astragalus, Oxytropis, swainsonine, lysosomal storage diseases.

  S-99.

  

  Tendon sutures.

• swainsonine an indolizidine alkaloid is an α-mannosidase and mannosidase II inhibitor that causes lysosomal storage disease and alters glycoprotein processing. Several plant species worldwide contain swainsonine. Found in Swainsona spp., Astragalus spp, Oxytropis spp Ipomoea spp. and Sida spp. It induces an acquired lysosomal storage disease; inhibits lysosomal α-d-mannosidase and Golgi mannosidase II and causes accumulation of large quantities of oligosaccharides composed of mannose and N-acetylglycosamine in lysosomes. In Astragalus and Oxytropis species swainsonine is produced by a fungal endophyte belonging to the Undifilum genus.

• Swale gag see Bayer gag.

• Swaledale sheep English carpetwool, meat sheep, black face, gray muzzle; similar to Black-faced mountain sheep.

• swallow 1. the amount of ingesta that can be swallowed at one time. 2. to perform the act of swallowing.

  • barium s. see barium swallow.
• swallowing [swahl′o-ing] the taking in of a substance through the mouth and pharynx and into the esophagus. It is a combination of a voluntary act and a series of reflex actions. Once begun, the process operates automatically. Called also deglutition.

  • s. disorders difficulty in swallowing may be caused by foreign body obstruction, by inflammation of the lining or by a defect in nervous control. The nerves involved are the sensory and motor branches of the trigeminal nerve, the hypoglossal, the facial, and the glossopharyngeal nerves. Called also dysphagia.
  • s. reflex begins as soon as the bolus of ingesta approaches the entry to the pharynx. In a series of reflex actions: breathing is halted, the soft palate elevates and closes the entrance to the nasal cavities, the tongue is clamped into the fauces, closing the exit from the pharynx back into the mouth, the epiglottis closes off the larynx, the pharynx contracts and forces the bolus into the esophagus, peristalsis-like movements in the esophagus carry the food to the cardia that relaxes, and the food is propelled into the stomach. Called also palatal reflex.
  • repeated s. a sign of partial esophageal obstruction.

• swamp cancer a common lesion of the skin and mucosae of horses in tropical and subtropical regions. The lesions are dense granulation tissue in the form of an ulcer that may rapidly extend to 8-in. diameter. The tissue may contain cores of necrotic yellow or black, sometimes calcified, material referred to colloquially as leeches, grains, or kunkurs. Distribution of the lesions varies with the etiology, but is concentrated mostly on the legs and ventral abdomen, below the medial canthus of the eye and on the muzzle and nearby mucosae. The cause may be any one of the following: Habronema megastoma larvae, or one of the fungi Pithium insidiosum, Basidiobolus ranarum, or Conidiobolus coronatus. Called also hyphomycosis, bursatti, cutaneous habronemiasis, summer sore, equine phycomycosis, equine pythiosis, Florida horse leech.

• swamp fever 1. equine infectious anemia. 2. leptospirosis.

• swamp itch see schistosome dermatitis.

• swampy back said of sheep and cattle; an exaggerated depression of the back between the withers and the loin.

• swan a member of the genera Cygnus (true swans) or Coscoroba (South American swan) in the family Anatidae (ducks, geese, and swans). Swans are the largest members of the family; most species are white, except for the Australian black swan (C. atratus). They have long flexible necks, paddle and swim, but they do not dive.

  S-100.

  

  Swaledale sheep.

• Swan–Ganz catheter [swahn′ ganz′] a balloon-tipped, end-hole, flowdirected catheter primarily used for right heart catheterization for the purpose of measuring pulmonary capillary wedge pressure or for quantification of cardiac output via thermodilution technique

• swan plant Gomphocarpusphysocarpus.

• Swann Report a 1969 report by the Swann Committee in Great Britain on the use of antibiotics in animal husbandry and veterinary medicine concluded there was a significant problem with regard to antimicrobial use in both human and veterinary practice and that the administration of antibiotics to farm livestock, particularly at sub-therapeutic levels, poses certain hazards to human and animal health.

• swarming [swawr′ming] 1. a phenomenon observed in cultures of Proteus spp. on solid media in which there is progressive spreading over the surface of the agar from the parent colony because of the high level of motility of the organism. 2. the periodic bee migration of the old queen and accompanying workers and drones from a full original hive that is left to be fought over by the new young queens.

• Swartzia madagascariensis see Bobgunnia madagascariensis.

• sway-backed [swa′bak] a marked lordosis in the back of a horse.

• sway response clinical test used in horses and cattle in which the animal is pulled laterally by the tail or pushed sideways on the rump while it is walking. Absence of the normal response, a resistance to being swayed or a smart sidestep to save from falling, is taken as indicating that normal balancing reflexes are not functioning.

• swayback one of the syndromes caused by a primary nutritional deficiency of copper. It may be congenital with lambs unable to stand or suck, spastic paralysis, sometimes blindness, or delayed, appearing at 3–6 weeks of age. There is incoordination and spasticity. See also enzootic ataxia.

• sweat [swet] the excretion of the sweat (sudoriparous) glands of the skin; perspiration. Sweating produces an evaporative cooling of the body, the importance varying between species, and also serves an excretory function. Substances eliminated in sweat include water, sodium chloride, and small amounts of urea, lactic acid, and potassium ions. In humans the ability to lose heat by sweating is much greater than that in domestic animals. Cattle have a high sweat rate (150 g/m²/h at 40°C), sheep lose less (32 g/m²/h), and dogs lose an insignificant amount. Horses probably have the highest sweat rate of all. Excessive sweating is called diaphoresis, hyperhidrosis.

  • s. glands the glands that secrete sweat, situated in the corium or subcutaneous tissue, and open onto the surface of the skin. They are of two types. (1) The atrichial (eccrine) sweat glands are simple unbranched, coiled, tubular glands that open directly onto the surface of the skin. They are innervated by cholinergic nerve fibers. In dogs, cats, rats, mice, and hamsters they are confined mainly to the footpads; in ruminants and pigs, the nasolabial region; the carpus of pigs; and the frog region of ungulates. (2) The epitrichial (apocrine) sweat glands are large, branched, specialized glands that empty into the upper portion of a hair follicle; located in haired areas of skin, as well as the external ear canal, eyelids, interdigital glands of small ruminants, the mental organ of pigs, and anal sacs of dogs and cats. They are sensitive to epinephrine (adrenaline) in the bloodstream. Called also sudoriferous, or sudoriparous, glands.
  • paratrichial s. gland see apocrine sweat gland.
  • s. scraper a semicircular band of metal with a handle to be dragged over a horse’s skin like a squeegee to remove excess moisture quickly.
• sweating [swet′ing] 1. the production of sweat. Its importance as a cooling mechanism varies between species, being important in horses but not so in pigs or dogs. See also sweat. 2. meat that has been in cold store condenses air moisture onto it when it comes out into room temperature and is said to sweat. 3. see fell-mongering.

  • s. pens pens in which sheep are held before shearing.

    S-101.

    

    Swamp cancer (habronemiasis).

  • s. sickness a tick toxicosis of young cattle caused by the bites of Hyalomma truncatum (syn. H. transiens) characterized by hyperemia of the mucosae and an extensive moist eczema that may lead to sloughing. Called also dyshidrosis tropicale, sweetsiekte.
• Swedish cattle indigenous to Sweden.

  • S. Friesian cattle Swedish version of Friesian.
  • S. red-and-white cattle red with small white markings, Swedish dairy cattle, originated from local breed plus Ayrshire.

• Swedish cattledog see Swedish Vallhund.

• Swedish Lapphund a medium-sized, spitz-type dog with a thick, standing haircoat in black or liver, sometimes with white marks on the chest, feet, and tip of tail. Very similar to, but larger than, the Finnish Lapphund. The breed is affected with hereditary neuronal abiotrophy and glycogenosis type II (Pompe’s disease). Called also Swedish Lapland dog.

• Swedish red spotted cattle a breed of red cattle with small white markings, a white-spotted red cow; used for dairying. Called also Swedish red and white cattle.

• Swedish Vallhund a small (20–32 lb), powerfully built, spitz-type, working dog with a long body, long head, pointed erect ears, and moderately short legs. (The breed standards call for a height to body length ratio of 2:5.) The coat is medium length, abundant, and woolly in shades of gray, brown, red, or yellow. The tail be curled, naturally short, or docked to a medium length. Called also Swedish cattle dog. Swedish shepherd.

• sweeney [swe′ne] see suprascapular paralysis.

• sweet [swēt] opposite of sour; taste of honey or sugar, not bitter, not salty, not sour.

  • s. feed a mixture of rolled grain and molasses used to tempt convalescent horses and cattle.
  • s. itch see equine allergic dermatitis.
• sweetbread an abattoir expression for calf thymus.

  • gut s. pancreas.
  • true s. thymus.

• sweetsiekte sweating sickness.

• swell body the alar fold in the nostril of dogs.

• swelled head [swel′hed] a disease of rams, a form of malignant edema caused by Clostridium septicum or other Clostridia spp. The swelling and emphysema are present only on the head and neck. The disease is thought to occur as a result of fighting. Called also ovine bighead.

• swellhead a disease of sheep caused by photosensitization. See also swelled head.

• swelling [swel′ing] 1. transient abnormal enlargement of a body part or area not due to cell proliferation. 2. an eminence, or elevation.

  • epiglottal s. the enlargements that appear on the floor of the pharynx of the embryo and subsequently take part in the formation of the lateral ventricles.
  • genital s. labioscrotal swelling (below).
  • labioscrotal s. in the male embryo overlie the inguinal canal development; in the female shift anteriorly and, in most species, disappear before birth.
  • lingual s’s. primordia of the tongue, the median swelling and the distal and proximal swellings arise from the ventral aspect of the stomodeum.
  • laryngeal s. eminences that develop lateral to the laryngotracheal groove in the embryo.
  • scrotal s. primordial scrotum.

• swept gain controls see time gain compensation.

• swill cooked edible garbage fed to pigs.

• swimmer see flat puppy syndrome.

• swimmer’s ear an explanation for otitis externa in dogs that swim or are bathed carelessly so that water enters the external ear canal. Excessive moisture in the ear predisposes to bacterial and fungal colonization.

• swimmer’s itch see schistosomiasis.

• swine pertaining to or emanating from swine (pigs, hogs). See also porcine.

  • African s. fever see African swine fever.
  • classical s. fever see classical swine fever.
  • s. dysentery a contagious chronic diphtheritic typhylocolitis of young pigs caused by Brachyspira hyodysenteriae and B. hampsonii, characterized by severe porridge-like diarrhea, sometimes dysentery, dehydration, and heavy morbidity, but usually low case fatality rates. See also drug augmented, drug delayed, drug diminished, and drug resistant swine dysentery.
  • s. erysipelas see erysipelas.
  • s. fever see classical swine fever, African swine fever.
  • s. infertility and respiratory syndrome see porcine reproductive and respiratory syndrome.

    S-102.

    

    Swelled head.

  • s. influenza a highly contagious upper respiratory disease of pigs associated with influenza A virus subtypes H1N1, H1N2, H3N2 belonging to the genus Orthomyxovirus; clinical signs include fever, stiffness, recumbency, labored breathing, sneezing, paroxysmal cough, and nasal and ocular discharge. Clinical signs in pigs are often enhanced by concurrent infection with Haemophilus influenzae. Since the 1930s, H1N1 viruses of swine origin have been occasionally recognized as zoonotic, but in 2009, there was a dramatic zoonotic pandemic, and many countries commenced national, mass, emergency, hastily implemented human vaccination programs. Although human infection has caused some deaths, usually in individuals with other medical conditions that compromise their immune systems, most uncomplicated human infections have been relatively mild compared to regular seasonal human influenza, with recovery in a few days.
  • s. paramyxovirus see paramyxovirus encephalomyelitis.
  • s. paratyphoid see salmonellosis.
  • s. plague historic disease with fibrinous pneumonia caused by Pasteurella multocida. Occurred in outbreak form with a number of litters of young pigs being affected within a short time.
  • s. vesicular disease is a highly infectious disease of pigs caused by an enterovirus related to human Coxsackie B5 virus. It is clinically indistinguishable from foot-and-mouth disease in pigs. Strains vary in virulence and disease may be subclinical, mild, or severe. Spread is by direct contact between pigs or indirectly by contact with contaminated feces and by swill feeding. Vesicular lesions occur at the coronet, causing severe lameness, and in the mouth and on the snout.
  • vesicular exanthema of s. see vesicular exanthema of swine.

• swineherd’s disease see leptospirosis.

• swinepox a disease caused by either of two pox-viruses, true swine poxvirus (suipoxvirus) or vaccinia virus. There are typical pox lesions, most commonly on the abdominal skin in adult pigs. Piglets may have lesions on the face and have a concurrent conjunctivitis, and some may die. Haematopinus suis is thought to transmit the disease in older pigs, whereas suckers probably are infected by contact with the sow’s udder.

  S-103.

  

  Colitis in swine dysentery.

• swinge coat a haircoat that is short, sparse, and curly.

• swingle-bar wooden spreader used to keep trace chains apart behind draft animals.

• Swiss frill a breed of canary characterized by a curved body and voluminous, frilled breast feathers, and a mantle with feathers falling symmetrically over the shoulders.

• Swiss mountain dog see Sennenhund.

• switch [swich] 1. in an x-ray machine, the on–off switch controls the input of electricity to the x-ray machine. 2. the hairy part of the tail of a cow. 3. in immunology refers to the change from the production of one form or class of antibody by a B lymphocyte to another; the differentiation occurs only in the C region of their heavy chain.

  • s. sites repetitive nucleotide sequences located between most of the C genes.

• switchgrass see Panicum virgatum.

• swollen head syndrome a disease of domestic poultry caused by a combination of a pneumovirus and adventitious bacteria, usually Escherichia coli. Often associated with outbreaks of rhinotracheitis in turkeys, thought to be caused by the same virus. Clinically the disease occurs in broiler breeders causing swelling of the periorbital and infraorbital sinuses and submandibular edema. Young birds also show signs of severe respiratory disease.

• swordtail a popular and colorful aquarium fish, Xiphophorus spp., characterized by its elongated caudal fins. Includes the green swordtail (X. hellerii) and many related species and hybrids.

• Sx abbreviation for surgery; used in medical records.

• sydecans a class of proteoglycans that are integral membrane proteins that function in cell matrix adhesion, interact with the cytoskeleton and may bind external signal molecules thereby participating in cell–cell signaling.

• Sydney silky see Silky terrier.

• sylade a chemical additive used in the making of ensilage. A strong suspect at one time to be related in some way to the etiology of the pyrexia–pruritus–hemorrhage syndrome of cattle.

• sylvatic [s l-vat′ik] found in the woods; occurring in animals of the forest.

  • s. plague see sylvatic plague.
  • s. rabies see sylvatic rabies.
  • s. ringworm see sylvatic dermatophytosis.

• sylvian aqueduct [sil′ve- n] see cerebral aqueduct.

• sylvian fissure [sil′ve- n] see sylvian sulcus.

• Sylvilagus the rabbit genus of lagomorphs in the family Leporidae; the cottontail rabbits.

• sym- word element. [Gr.] union, association.

• symballophone [sim-bal′o-fōn] a stethoscope with two chest pieces, making possible the comparison and localization of sounds.

• symbiont [sim′bi-ont, sim′be-ont] an organism or species living in a state of symbiosis.

• symbiosis [sim″bi-o′sis] the biological association of two individuals or populations of different species, classified as mutualism, commensalism, parasitism, amensalism or synnecrosis, depending on the advantage or disadvantage derived from the relationship.

• symbiote [sim′bi-ōt] symbiont.

• symbiotic mange [sim″bi-ot′ik] chorioptic mange.

• symbiotics commercial products that combine prebiotics with probiotics.

• symblepharon [sim-blef′ -ron] adhesion of conjunctiva to conjunctiva or to cornea due to ulceration of both surfaces and exposure of subepithelial corneal or conjunctival stroma. Occurs most frequently as a sign of feline herpesvirus infection in cats or following chemical burns in any species.

  S-104.

  

  Swinepox.

• symblepharopterygium [sim-blef″ -ro-tr-ij′e- m] symblepharon in which the adhesion is a cicatricial band resembling a pterygium.

• symmelus [sim′ -l s] a fetus with fused legs.

• symmetrical [sľ-met′rľ-k l] being identical on each side of a point or plane.

• symmetry [sim′ -tre] correspondence in size, form, and arrangement of parts on opposite sides of a plane, or around an axis. Often used to describe conformation.

  • bilateral s. the configuration of an irregularly shaped body (such as the body of a higher animal) that can be divided by a longitudinal plane into halves that are mirror images of each other.
  • radial s. that in which the body parts are arranged regularly around a central axis.

• sympathectomize [sim″p -thek′t -mīz] to deprive of sympathetic innervation.

• sympathectomy [sim″p -thek′t -me] excision or interruption of some portion of the sympathetic nervous pathway. The operation produces temporary vasodilatation leading to improved nutrition of the part supplied by the vessel.

  • chemical s. the interruption of the transmission of impulses through a sympathetic nerve by chemical agents.
  • periarterial s. surgical removal of the sheath of an artery containing the sympathetic nerve fibers; it produces temporary vasodilatation.
• sympathetic [sim″p -thet′ik] pertaining to the sympathetic nervous system.

  • acute s. blockade trauma to the cervical spinal cord may be associated with bradycardia and hypotension.
  • s. chain the sympathetic trunk whose ganglia suggest a chain of beads.
  • s. cholinergic vasodilator fibers a system of efferent dilator nerves distributed only to skeletal muscles; the existence of the system has been verified only in cats and dogs; in other species where it is not present, vasodilation is achieved only by relaxation of vasoconstrictor tone.
  • s. nerves 1. see sympathetic trunk (below). 2. any nerve of the sympathetic nervous system.
  • s. nervous system the part of the autonomic nervous system whose preganglionic fibers arise from cell bodies in the thoracic and lumbar segments of the spinal cord; postganglionic fibers are distributed to the heart, smooth muscle, and glands of the entire body.
  • s. outflow the preganglionic fibers from the nerve cells in the thoracolumbar cord.
  • s. regurgitation see neurotic regurgitation.
  • s. trunk two long ganglionated nerve strands, one on each side of the vertebral column, extending from the base of the skull to the coccyx.
  • s. trunk ganglia ganglia situated segmentally along the paired sympathetic trunks beside the vertebral bodies.

• sympathicoblast [sim-path′ľ-ko-blast″] sympathoblast.

• sympathicoblastoma [sim-path″ľ-ko-blas-to′m ] a malignant tumor containing sympathicoblasts.

• sympathicolytic [sim-path″ľ-ko-lit′ik] sympatholytic.

• sympathicomimetic [sim-path″ľ-ko-mi-met′ik] sympathomimetic.

• sympathicotonia [sim-path″ľ-ko-to′ne- ] a stimulated condition of the sympathetic nervous system marked by vascular spasm, heightened blood pressure, and the dominance of other sympathetic functions.

• sympathicotripsy [sim-path″ľ-ko-trip′se] surgical crushing of a nerve, ganglion, or plexus of the sympathetic nervous system.

• sympathicotropic [sim-path″ľ-ko-tro′pik] 1. having affinity for, or exerting its principal effect, on the sympathetic nervous system. 2. an agent with such properties.

• sympathicus the sympathetic nervous system.

• sympathoadrenal [sim″p -tho--dre′n l] 1. pertaining to the sympathetic nervous system and the adrenal medulla. 2. involving the sympathetic nervous system and the adrenal glands, especially increased sympathetic activity that causes increased secretion of epinephrine (adrenaline) by the adrenal medulla and norepinephrine (noradrenaline) by the postganglionic sympathetic nerve endings.

  • s. discharge the sympathoadrenal system can discharge as one unit and prepare the animal in all systems for immediate fight or flight. There is an increase in heart rate, ventricular contractile strength, cardiac output, blood pressure plus pupillary dilatation, increased respiratory rate, bronchiolar dilatation, diversion of blood flow from the splanchnic to skeletal muscle circulation, and elevation of the blood glucose concentration.

• sympathoblast [sim-path′o-blast″] an embryonic cell that develops into a sympathetic nerve cell. See also sympathogonium.

• sympathoblastoma [sim″p -tho-blas-to′m] sympathicoblastoma.

• sympathogonioma [sim″p -tho-go″ne-o′m] sympathicoblastoma.

• sympathogonium [sim″p -tho-go′ne- m] pl. sympathogonia [Gr.] an embryonic cell that develops into a sympathetic cell.

• sympatholytic [sim″p -tho-lit′ik] antiadrenergic: blocking transmission of impulses from the adrenergic (sympathetic) postganglionic fibers to effector organs or tissues, inhibiting such sympathetic functions as smooth muscle contraction and glandular secretion. Also, an agent that produces such an effect.

• sympathomimetic [sim″p -tho-mi-met′ik] 1. producing effects resembling those of impulses transmitted by the adrenergic postganglionic fibers of the sympathetic nervous system. 2. an agent that produces such an effect.

• sympathy [sim′p -the] an influence produced in any organ by disease or disorder in another part. See also sympathetic ophthalmia.

• symphalangism [sim-fal′ n-jiz- m] congenital ankylosis of the proximal phalangeal joints.

• Symphoromyia [sim″for-o-mi′y ] a genus of flies that is ordinarily predatory on other flies but that are blood-suckers and do inflict a painful bite. They are members of the family Rhagionidae. Includes S. atripes, S.crassicornis and S. hirta.

• symphyseal, symphysial [sim-fiz′e- l] pertaining to a symphysis, as the join between two sides of the mandible at their front ends.

  • mandibular s. fracture separation of the two mandibles at their symphysis; a common injury in dogs and cats caused by blunt force trauma.

• symphysiodesis surgical fusion or thermal destruction of the pubic symphysis in young dogs with hip dysplasia to increase the angle of the acetabulum and reduce hip joint laxity. Called also juvenile pubic symphysiodesis (JPS).

• symphysiorrhaphy [sim-fiz″e-or′ -fe] suture of a divided symphysis.

• symphysiotomy [sim-fiz″e-ot′ -me] surgical division of a symphysis.

  • mandibular s. performed in order to achieve better access to the pharynx and posterior buccal cavity.
  • pubic s. performed to facilitate delivery, most commonly in under-age or overfat heifers. In the management of chronic obstipation in cats, the pelvic diameter is enlarged by symphysiotomy and maintained with an iliac bone graft.
• symphysis [sim′fľ-sis] pl. symphyses [Gr.] a type of joint in which the apposed bony surfaces are firmly united by a plate of fibrocartilage or cartilage; e.g., intermandibular joint, pelvic symphysis. There is usually cartilage against each bone and fibrous tissue or fibrocartilage in the middle.

  • ischiatic s. the line of fusion between the bodies of the ischia.
  • mandibular s. the joint between the two halves of the mandible that allows each half to rotate, as in the jaws of the dog, cat, ruminants, and many other species, is a cartilaginous symphysis. In the jaws of horses and pigs, the mandibles are fused together.
  • pelvic s. the combined pubic and ischiatic symphyses, a cartilaginous symphysis.
  • pubic s., s. pubis the line of union of the bodies of the pubic bones in the median plane.

• Symphytum [sim′fľ-t m] genus in plant family Boraginaceae; contain pyrrolizidine alkaloids and can cause poisoning if eaten in large quantities. Include S. asperum (rough comfrey), S. officinale (comfrey), S. × uplandicum (Russian comfrey).

• Symplocarpus foetidus North American member of the plant family Araceae; contains calcium oxalate raphide crystals that cause stomatitis; called also skunk cabbage.

• sympodia [sim-po′de- ] fusion of the lower extremities.

• symport [sim′port] the process of transporting two substances across a membrane in the same direction by a common carrier mechanism.

• symptom [simp′t m] any indication of disease perceived by the patient and a term therefore not applicable to animals.

• symptomatic [simp″to-mat′ik] 1. pertaining to or of the nature of a symptom. The word symptom is not used in veterinary medicine because the subjective sensations of our patients are not known to us. However, because there is no comparable word relating to clinical sign, the principal means by which veterinarians arrive at diagnoses, it is customary to use the word symptomatic in this context, that is as pertaining to or in the nature of a clinical sign. 2. indicative (of a particular disease or disorder). 3. exhibiting the symptoms of a particular disease but having a different cause. 4. directed at the allaying of symptoms, as symptomatic treatment.

  • s. anthrax see blackleg.

• symptomatology [simp″t -m-tol′ -je] 1. the study of the science of clinical signs. 2. the combined clinical signs of a disease.

• symptomatolytic [simp″to-mat″o-lit′ik] causing the disappearance of clinical signs.

• sympus [sim′p s] symmelus.

  S-105.

  

  Rostral view of feline mandibular symphysis. From Colville T, Bassert, JM Clinical Anatomy and Physiology for Veterinary Technicians, 3rd Edition, Elsevier. 2016.

• syn- word element. [Gr.] union, association.

• Synadenium South African plant genus in the family Euphorbiaceae; some used as tropical garden shrubs; contain a milky sap (latex) that irritates mucosae, causes diarrhea, but the toxin has not been identified. Includes S. cupulare (S. arborescens crying tree), S. grantii (African milk bush).

• synanthropic ecologically associated with humans.

• Synapis [sľ-nap′sis] see Sinapis.

• synapse [sin′aps] the junction between the processes of two neurons or between a neuron and an effector organ, where neural impulses are transmitted by chemical means. The impulse causes the release of a neurotransmitter (e.g., acetylcholine or norepinephrine) from the presynaptic membrane of the axon terminal. The neurotransmitter molecules diffuse across the synaptic cleft, bind with specific receptors on the postsynaptic membrane, causing depolarization or hyperpolarization of the postsynaptic cell. See also neuron.

  • adrenergic s. the neurotransmitter is norepinephrine. See also adrenergic (1).
  • axoaxonic s. see axoaxonic.
  • axodendritic s. see axodentritic.
  • axodendrosomatic s. one between the axon of one neuron and the dendrites and body of another.
  • axosomatic s. see axosomatic.
  • cholinergic s. the neurotransmitter is acetylcholine. See also cholinergic.
  • dendrodendritic s. one from a dendrite of one cell to a dendrite of another.
  • excitatory s. a synapse in which the transmission of impulses is electrical not chemical. Found only in fish and invertebrates.
  • inhibitory s. hyperpolarizing electrical current is used to raise the threshold for the stimulation of a discharge of an impulse from the particular kind of nerve cell, found only in fish.

• synapsis the pairing off and union of homologous chromosomes from male and female pronuclei at the start of meiosis.

• synaptic [sľ-nap′tik] pertaining to a synapse.

  • s. cleft a narrow space between the plasma membranes of the presynaptic and postsynaptic cells.
  • s. junction see synapse.
  • s. vesicle one located in the axon terminal of a presynaptic cell, containing neurotransmitter substances.

• synaptosomes [sin-ap′to-sōm″] discrete units of pre- and postsynaptic membranes.

• synarthrodia [sin″ahr-thro′de- ] synarthrosis.

• synarthrodial [sin″ahr-thro′de- l] pertaining to a synarthrosis.

• synarthrophysis [sin-ahr″thro-fi′sis] any ankylosing process.

• synarthrosis [sin″ahr-thro′sis] pl. synarthroses [Gr.] previously used term for a form of joint in which the bony elements are united by continuous intervening strip of fibrous or cartilaginous tissue to make them immobile. Called also fixed joint.

• synbiotic a food product that contains both probiotics and prebiotics.

• syncanthus [sin-kan′th s] adhesion of the eye to the orbital structures.

• syncephalus [sin-sef′ -l s] conjoined twins with heads fused into one, there being a single face, with four ears.

• synchilia [sin-ki′le- ] congenital adhesion of the lips.

• synchiria [sin-ki′re- ] reference of sensation to the opposite side on application of a stimulus.

• synchondrosis [sin″kon-dro′sis] pl. synchondroses [Gr.] a type of cartilaginous joint such as found in most growing long bones in which the diaphysis and epiphysis are united by the cartilage of a growth plate that is usually converted into bone before or during early adult life and that serves to allow growth. Such joints similarly occur in the intermandibular, intersternebrales (syn. sternales), spheno-occipitales locations.

  • intersphenoidal s. between the presphenoid and basisphenoid bones; in some achondroplastic conditions the presence of this synchondrosis contributes to the abnormal growth of the skull creating a brachycephalic deformity such as occurs in bulldog calves.

• synchondrotomy [sin″kon-drot′ -me] division of a synchondrosis.

• synchronism [sing′kr -niz- m] occurrence at the same time.

• synchronization [sing″kr -nľ-za′sh n] arranging that events shall occur at the same time.

  • estrus s. see estrus synchronization.
• synchronous [sing′kr -n s] occurring at the same time.

  • s. timer an oldfashioned timer on an x-ray machine that permits of very short exposure times but has to be reset after each exposure. Use of this kind of timer is no longer legal in most countries.
• synchysis [sin′kľ-sis] a softening or fluid condition of the vitreous body of the eye.

  • s. scintillans floating mobile cholesterol crystals in the vitreous body; develops as a secondary degenerative change. Once called cholesterolosis bulbi.

• synclonus [sin′klo-n s] muscular tremor or successive clonic contraction of various muscles together.

• syncope [sing′k -pe] a temporary suspension of consciousness due to cerebral dysfunction, especially hypoxia; fainting.

  • cardiac s. sudden loss of consciousness due to cerebral hypoxia caused by ventricular asystole, extreme bradycardia or ventricular fibrillation.
  • drug-induced s. can result from abnormalities of cardiac rhythm, caused by treatment with digitalis, and hypotension caused by drugs such as diuretics, promazine and phenothiazine tranquilizers, and peripheral vasodilating agents.
  • laryngeal s. tussive syncope.
  • Stokes–Adams s. see Stokes–Adams disease.
  • swallow s. syncope associated with swallowing, a disorder of atrioventricular conduction mediated by the vagus nerve.
  • tussive s. brief loss of consciousness associated with paroxysms of coughing.
  • vasovagal s. see vasovagal attack.
• syncytial [sin-sish′ l] pertaining to or producing a syncytium.

  • bovine s. virus see Retroviridae.
  • feline s. virus see Retroviridae.
  • s. giant cell multinucleated mass of protoplasm formed by the fusion of a number of cells; a stage in the formation of a syncytium.

• syncytiotrophoblast [sin-sit″e-o-tro′fo-blast] the outer syncytial layer of the trophoblast in the human placenta.

• syncytium [sin-sish′e- m] a multinucleate cellular mass produced by the fusing of cells.

  • s.-forming virus members of the family Retroviridae, genus Spumavirus. The best known of these viruses are found in cats and cattle. It should be noted, however, that viruses of several families, including herpesviruses, paramyxoviruses, coronaviruses, and retroviruses, produce syncytia.

• syndactylia [sin″dak-til′e- ] syndactyly.

• syndactylism [sin-dak′t -liz- m] syndactyly.

• syndactyly [sin-dak′t -le] fusion of the claws or digits. Typical cases of syndactylism are externally recognized by the presence of a single hoof-like structure instead of the normally paired claws. An inherited defect in several breeds of cattle. Some affected animals are also susceptible to hyperthermia. Also an inherited defect in Birman cats.

• syndectomy [sin-dek′t -me] peritectomy.

• syndesis [sin′d -sis, sin-de′sis] 1. arthrodesis. 2. synapsis.

• syndesmectomy [sin″d z-mek′t -me] excision of a portion of ligament.

• syndesmitis [sin″dez-mi′tis] 1. inflammation of a ligament. 2. conjunctivitis.

  • s. ossificans ossification of a ligament. The ventral longitudinal ligament may be affected, especially in young Boxer dogs.

• syndesm(o)- word element. [Gr.] connective tissue, ligament.

• syndesmochorial [sin″d z-mo-kor′e- l] see syndesmochorial placenta.

• syndesmography [sin″d z-mog′r -fe] a description of the ligaments.

• syndesmology [sin″d z-mol′ -je] scientific study of the ligaments and joints.

• syndesmoma a tumor of connective tissue.

• syndesmoplasty [sin-dez′mo-plas″te] plastic repair of a ligament.

• syndesmosis [sin″d z-mo′sis] pl. syndesmoses [Gr.] a joint in which the bones are united by fibrous connective tissue forming an interosseous membrane or ligament that allows a modest amount of movement.

• syndesmotomy [sin″d z-mot′ -me] incision of a ligament.

• syndrome [sin′drōm] a combination of clinical signs resulting from a single cause or so commonly occurring together as to constitute a distinct clinical picture. For specific syndromes, see under the specific name, as flat puppy syndrome, Cushing’s syndrome.

  • s. recognition a preliminary stage in the making of a diagnosis based on the recognition of a particular combination of clinical signs.
  • testicular feminizing s. see testicular feminization syndrome.
  • triple XXX s. see XXX.
  • sick sinus s a group of abnormal heart rhythms caused by a malfunction of the sinus node,

• syndrome of inappropriate secretion of antidiuretic hormone (SIADH) a syndrome in which the secretion of antidiuretic hormone (ADH) is not inhibited by appropriately by hypotonicity of extracellular fluid or nonosmotic stimuli. Euvolemic hyponatremia is produced, with hyposmolar plasma and increased urine sodium excretion. Rare in dogs and cats, SIADH has been associated with neoplasia, central nervous system disorders, canine heartworm disease, liver disease, and certain drugs.

• syndromic [sin-drom′ik] occurring as a syndrome.

• syndromology [sin″drom-ol′ -je] the field concerned with the taxonomy, etiology, and patterns of congenital malformations.

• synechia [sľ-nek′e- ] pl. synechiae [Gr.] adhesion, as of the iris to the cornea or the lens.

  • annular s. adhesion of the whole pupillary rim of the iris to the lens; a precursor to iris bombe.
  • anterior s. adhesion of the iris to the cornea.
  • peripheral anterior s. adhesion of the peripheral iris root to the cornea.
  • posterior s. adhesion of the iris to the anterior lens capsule.
  • total s. adhesion of the whole posterior surface of the iris to the anterior lens capsule.
  • s. vulvae a congenital condition in which the labia are sealed in the midline, with only a small opening below the clitoris through which urination may occur.

• synechotomy [sin″ -kot′ -me] incision of a synechia.

• synencephalocele [sin″ n-sef′ -lo-sēl″] encephalocele with adhesions to adjoining parts.

• synencephaly [sin″ n-sef′ -le] a fetal anomaly in which there are two bodies and one head. Called also disomus.

• syneresis [sľ-ner′ -sis] a drawing together of the particles of the disperse phase of a gel, with separation of some of the disperse medium and shrinkage of the gel. Occurs as a result of liquefaction of the vitreous as a normal aging change or following pathology resulting in vitreal hemorrhage, for example.

• synergism [sin′ r-jizm] the joint action of agents so that their combined effect is greater than the sum of their individual parts, e.g., antibiotic synergism or potentiation..

• synergist [sin′ r-jist] an agent that acts with or enhances the action of another.

• synergy [sin′ r-je] correlated action by two or more structures or drugs such that the combined effect is greater than the sum of the individual effects.

• syngamiasis infestation with Syngamus trachea in fowl, turkey, pheasant, guinea fowl, goose, and wild birds. Causes pneumonia while migrating through the lungs. In the trachea, causes tracheitis and anemia because of heavy blood-sucking. The predominant clinical signs are dyspnea, head shaking, and spasmodic gaping.

  S-106.

  

  Calf with syndactyly.

• Syngamus [sin′g -m s] a genus of nematodes in the strongyloid family Syngamidae.

  • S. skrjabinomorpha found in the domestic goose and in chickens.
  • S. trachea found in fowl, turkey, pheasant, guinea fowl, goose, and wild birds. Commonly referred to as ‘gapeworm’. Causes pneumonia while migrating through the lungs. In the trachea causes tracheitis and anemia because of heavy blood-sucking. The predominant clinical signs are dyspnea, head shaking, and spasmodic gaping.

• syngamy [sing′g -me] a method of reproduction in which two individuals (gametes) unite permanently and their nuclei fuse; sexual reproduction. A common form of reproduction in protozoa.

• syngeneic [sin″j -ne′ik] in transplantation biology, denoting individuals or tissues having almost identical genotypes, i.e., animals of the same inbred strain, or their tissues. Grafts can be as readily exchanged between syngeneic animals as between identical twins that are called isogeneic.

• syngenesis [sin-jen′ -sis] 1. the origin of an individual from a germ derived from both parents and not from either one alone. 2. the state of having descended from a common ancestor.

• syngraft [sin′graft] see isograft.

• Synhimantus a large genus of nematodes that infect birds; members of the family Acuariidae.

  • S. spiralis, S. nasula found in the walls of the proventriculus, esophagus, gizzard, and sometimes intestine of most domestic and wild bird species, mainly in water birds, e.g., pelicans, but also in hawks and owls. It causes severe lesions and affected birds waste away and die. Losses may be heavy.

• synkaryon [sin-kar′e-on] hybrid cell with one nucleus that was formed by fusion of the nuclei from two different parental cells.

• synkinesis [sin″ki-ne′sis] an associated movement; an unintentional movement accompanying a volitional movement.

• synnecrosis [sin″ -kro′sis] symbiosis in which the relationship between populations (or individuals) is mutually detrimental.

• synodontia see fusion tooth.

• synonym an alternative name for the same disease, sign, bacteria, etc. A key word or sign may have a number of synonyms.

• synophthalmus, synophthalmos, synophthalmia [sin″of-thal′m s] cyclops.

• synorchism, synorchidism [sin′or-kiz- m] congenital fusion of the testes into one mass.

• synosteotomy [sin″os-te-ot′ -me] dissection of the joints.

• synostosis [sin″os-to′sis] pl. synostoses [Gr.] normal or abnormal union of two bones by osseous material.

  • radioulnar s. occurs between the radius and ulna as a result of unsatisfactory reduction of fractures.

• synotia [sľ-no′she- ] a developmental anomaly with fusion of the ears, or their location near the midventral line in the upper part of the neck.

• synotus [sľ-no′t s] a fetus exhibiting synotia.

• synovectomy [sin″o-vek′t -me] excision of a synovial membrane, as of that lining the capsule of the knee joint.

• synovia [sľ-no′ve- ] synovial fluid; the yellow-white transparent viscid fluid secreted by the synovial membrane and found in joint cavities, bursae, and tendon sheaths that lubricates moving parts and nourishes articular cartilage.

• synovial [si-no′ve-?l] of, pertaining to, or secreting synovia.

  • s. fluid a protein-free dialysate of plasma with added hyaluronate, glycoproteins, and other unidentified substances added by the synovial membrane. Called also synovia.

    S-107.

    

    Lens subluxation in a fox terrier. A focal posterior synechia adheres to the anterior lens capsule at the 2- o’clock position.

  • s. folds pleats of synovial membrane infoldings into joint cavities.
  • s. fossa cartilage-free nonarticulating areas in synovial joint articular surfaces found in the larger joints of larger animals. They are recessed below the surface of the cartilage and are unevenly sculpted.
  • s. gout see articular gout.
  • s. joint a specialized form of articulation permitting more or less free movement, the union of the bony elements being surrounded by an articular capsule enclosing a cavity lined by synovial membrane. Formerly called diarthrosis.
  • s. membrane the inner of the two layers of the articular capsule of a synovial joint; composed of loose connective tissue and having a free smooth surface that lines the joint cavity; it secretes the synovia.
  • s. mucin the lubricant in synovial joints; an acidoglycoprotein, the acid polysaccharide portion of which is hyaluronan.
  • s. villus see synovial villus.

• synovialis [sľ-no″ve-a′lis] synovial.

• synovialoma, synovioma [sľ-no″ve- -lo′m] a tumor of synovial membrane origin.

• synoviocytes [sľ-no′ve-o-sīt] cells of the synovial membrane are of two types: type A are mainly phagocytic and pinocytic; type B are chiefly synthesizers. Seen in cytological examination of joint fluid.

• synovioma [sľ-no″ve-o′m ] synovialoma. Tumor of the synovium.

• synoviorthese [sľ-no″ve-or-the′sis] irradiation of the synovium by intraarticular injection of radiocolloids to destroy inflamed synovial tissue.

• synovitis [sin″o-vi′tis] inflammation of a synovial membrane, usually painful, particularly on motion, and characterized by fluctuating swelling, due to effusion in a synovial sac.

  • dry s. synovitis with little effusion.
  • granulomatous s. see granulomatous synovitis/arthritis.
  • infectious avian s. an infectious disease of broiler chickens and young turkeys caused by Mycoplasma synoviae and manifested by acute or chronic exudative synovitis, tenosynovitis, or bursitis. The birds are lame, the joints are often swollen, and there is difficulty in moving and in maintaining a standing posture.
  • lymphocytic s. see lymphocytic–plasmacytic synovitis (below).
  • lymphocytic–plasmacytic s. an immune-mediated inflammatory joint disease seen most often in the stifle of dogs, with signs of joint laxity and instability resembling rupture of the cranial cruciate ligament. The synovial membrane is greatly thickened. Concurrent cranial cruciate ligament degeneration may be present.

    S-108.

    

    Congenital metatarsal bone synostosis in a dog.

  • pigmentary villonodular s. a disease of humans characterized by the development of nodular and villous synovial proliferations; similar lesions are reported in horses and dogs; pigmentation results from deposition of blood pigments.
  • purulent s. synovitis with effusion of pus in a synovial sac.
  • serous s. synovitis with copious nonpurulent, serous effusion.
  • s. sicca dry synovitis.
  • simple s. synovitis with clear or slightly turbid effusion.
  • tendinous s. inflammation of a tendon sheath.
  • villonodular s. proliferation of synovial tissue, especially of the knee joint, composed of synovial villi and fibrous nodules infiltrated by giant cells and macrophages.

• synovium [sľ-no′ve- m] a synovial membrane.

• synsacrum [sin-sa′kr m] the fused lumbar and sacral vertebra and pelvic girdle of birds.

• synsarcosis [sin-sahr-ko′sis] union of parts of the skeleton by muscles, e.g., attachment of the thoracic limb to the trunk in any of the domestic animals.

• syntenic groups [sin-ten′ik] see linkage (2).

• synteny [sin′t -ne] 1. the co-localization of two gene loci on the same chromosome. 2. in genomics, the gene order is conserved along the chromosomes of two species.

• synthase [sin′thās] any enzyme that catalyzes a synthetic reaction, classified as belongng to the lyase family. Originally defined as enzymes not using energy from nucleoside triphosphates, but now covers all synthetic enzymes.

• synthesis [sin′th -sis] creation of a compound by union of elements composing it, done artificially or as a result of natural processes. See also biosynthesis.

• synthesize [sin′th -sīz] to produce by synthesis.

• synthetase [sin′th -tās] ligase; any of a class of enzymes that catalyze the joining together of two molecules coupled with the breakdown of a pyrophosphate bond in ATP or a similar triphosphate.

  • aminoacyl-tRNA s’s see tRNA.
  • heme s. see ferrochelatase.
• synthetic [sin-thet′ik] artificially produced.

  • s. organic dyes includes azo, acridine, and rosaniline dyes. Used topically as weak antimicrobial agents.
  • s. reaction a metabolic reaction in which a substance is formed from two precursors.
  • s. rubber may contain tricresyl phosphate and cause intoxication of animal having access to litter made of it.

• syntopy [sin′t -pe] the position of an organ relative to other organs.

• syntrophoblast [sin-trof′o-blast] syncytiotrophoblast.

  S-109.

  

  Structure of a synovial joint, the knee or stifle.

• Syphacia obvelata [si-fa′se- ] a pinworm of the family Oxyuridae, found in the colon of mice and hamsters; a common parasite in laboratory colonies.

• syphilis [sif′ľ-lis] in rabbits, see spirochetosis (2).

• syringe [sľ-rinj′, sir′inj] an instrument for introducing fluids into or withdrawing them from the body.

  • bulb s. a compressible rubber bulb with a pierced, pointed end that allows suction and expulsion of fluids. Useful in irrigating ears or small cavities as in abscesses.
  • s. driver an electronically controlled syringe or pump used for delivering small volumes of fluid at a constant rate.
  • hypodermic s. one for introduction of liquids through a hollow needle into tissues.
  • pole s. a syringe on a long pole so that the syringe can be operated from a distance, e.g., through the bars of a cage.
  • projectile s. see blow dart.

• syringectomy [sir″in-jek′t -me] excision of a fistula.

• syringitis [sir″in-ji′tis] inflammation of the pharyngotympanic (auditory, eustachian) eustachian tube.

• syring(o)- word element. [Gr.] tube, fistula.

• syringoadenoma [sľ-ring′go-ad″ -no′m] synonym for a sweat gland adenoma

• syringobulbia [sľ-ring′go-bul′be- ] the presence of fluid-filled cavities in the medulla oblongata and pons.

• syringocarcinoma [sľ-ring″go-kahr″sľ-no′m ] neoplasm of a sweat gland.

• syringocele [sľ-ring′go-sēl] a cavity-containing herniation of the spinal cord through the bony defect in spina bifida.

• syringocystadenoma [s -ring″go-sis-tad″--no′m] adenoma of the sweat glands; called also hidradenoma.

• syringocystoma [s -ring″go-sis-to′m] a cystic tumor of a sweat gland.

• syringomeningocele meningocele resembling syringomyelocele.

• syringomyelia [sľ-ring″go-mi-e′le- ] 1. the presence of fluid-filled cavities in the substance of the spinal cord, with destruction of nervous tissue. Clinical signs are posterior paralysis, or if the animal is able to stand the posture is a wide spacing of the feet and overextension of the legs when walking. An inherited trait in Weimaraner dogs. See also spinal dysraphism. 2. Also commonly used to refer to a condition in Cavalier King Charles spaniels and other small breeds that involves abnormal occipital bone formation and herniation of the caudal part of the cerebellum through the foramen magnum in addition to pockets of fluid within the spinal canal. Clinical signs include scratching at the side of the shoulder or neck due to apparent dysesthesia, and paroxysms of screaming in pain with no or minimal inciting stimuli. Other terms used for this condition include caudal occipital malformation syndrome (COMS) and Chiari-like malformation due to its similarity to Arnold Chiari Type I malformation in humans.

• syringomyelitis [sľ-ring″go-mi″ -li′tis] inflammation of the spinal cord with the formation of cavities.

• syringomyelocele [sľ-ring″go-mi′ -lo-sēl] hernial protrusion of the spinal cord through the bony defect in spina bifida, the mass containing a cavity connected with the central canal of the spinal cord.

• Syringophilus a genus of trombidiform mites found inside the quills of feathers of birds. Includes S. bipectinatus (fowl), S. columbae (pigeons), and S. uncinatus (syn. Cheyletoides uncinata) (peacocks).

• syringotomy [sir″in-got′ -me] incision of a fistula.

• syrinx [sir′inks] 1. a tube or pipe; a fistula. 2. the principal voice organ of birds; a laterally compressed cartilaginous box at the caudal end of the trachea and the beginning of the bronchi.

  • s. membrane one that creates the voice of birds; comprises two pairs of vibrating membranes, the internal and external tympanic membranes.

• syrinxitis inflammation of the syrinx in birds; may be characterized by snoring, coughing, gagging, cyanosis, and a threat of asphyxiation.

• Syrmaticus reevesii Reeves pheasant.

• syrup [sir′ p] a viscous concentrated solution of a sugar, such as sucrose, in water or other aqueous liquid; combined with other ingredients, such a solution is used as a flavored vehicle for medications.

• systaltic [sis-tawl′tik] alternately contracting and dilating; pulsating.

• system [sis′t m] 1. a set or series of interconnected or interdependent parts or entities (objects, organs, or organisms) that act together in a common purpose or produce results impossible by action of one alone. 2. an organized set of principles or ideas. An open system is one in which there is an exchange of matter, energy, and information with the environment; in a closed system, there is no such exchange. A living system cannot survive without this exchange, but in order to survive it must maintain pattern and organization in the midst of constant change. Control of self-regulation of an open system is achieved by dynamic interactions among its elements or components. The result of self-regulation is referred to as the steady state; that is, a state of equilibrium. homeostasis is an assemblage of organic regulations that act to maintain steady states of a living organism. Definitions of individual systems are to be found under those titles, e.g., alimentary system.

  • general s’s theory a theory of organization proposed by Ludwig von Bertalanffy in the 1950s as a means by which various disciplines could communicate with one another, and duplication of efforts among scientists could be avoided. The theory sought universally applicable principles and laws that would hold true regardless of the kind of system under study, the nature of its components, or the interrelationships among its components. Since the introduction of the general systems theory, theoretical models, principles, and laws have been developed that are of great value to scientists in all fields, including those of medicine, nursing, other health-related professions, and in veterinary medicine.
  • heterogeneous s. a system or structure made up of mechanically separable parts, as an emulsion or suspension.
  • homogeneous s. a system or structure made up of parts that cannot be mechanically separated, such as a solution.

• systema [Gr.] system.

• systematic [sis″t -mat′ik] in an organized manner; according to some system.

• Systematized Nomenclature of Medicine (SNOMED) see SNOMED.

• Système International d’Unités the International System of Units; introduced in 1977, a universally accepted system of units of measure and providing units for the health professions; abbreviated SI. See Table 1. See also SI Units.

• systemic [sis-tem′ik] pertaining to or affecting the body as a whole.

  • s. vascular resistance resistance to blood flow through the systemic circulation excluding the pulmonary circulation. Prime determinant is the length and diameter of small arteries, and resistance is determined by the length of vessels, autonomic tone affecting diameter of the resistance vessels, and by blood viscosity. Drugs that cause vasoconstriction increase systemic vascular resistance. Vasodilation (arterial) decreases systemic vascular resistance.
    Calculated using the formula:

    Resistance ((dyne × sec)/cm⁵) = 80 × (Mean Arterial Pressure – Mean Venous Pressure or CVP) / Cardiac Output,

    where CVP is central venous pressure or right atrial mean pressure.
    See also pulmonary vascular resistance.
• systole [sis′to-le] the contraction, or period of contraction, of the heart, especially of the ventricles, during which blood is forced into the aorta and pulmonary artery.

  • atrial s. contraction of the atria by which blood is forced into the ventricles; it precedes ventricular systole.
  • extra s. see extrasystole.
  • ventricular s. contraction of the ventricles, forcing blood into the aorta and pulmonary artery.

• systolic [sis-tol′ik] pertaining to or emanating from systole.

• syzygy [siz′ -je] 1. the fusion of organs without the loss of identity by either. 2. an association of two protozoa laterally or end-to-end for the asexual exchange of genetic material. 3. the pairing of chromosomes during meiosis.