Table 11.1.
Physical Findings.
| Abnormality | Potential Diagnosis |
|---|---|
| Pale mucous membranes, extremities, or eyes | Anemia (if rat appears otherwise relatively normal) |
| Excessive or too frequent blood collection | |
| Circulatory deficiency (if animal appears weak or depressed) | |
| Alopecia with normal, intact skin | Physical abrasion from cage or feeder |
| Self-grooming or barbering from cage mate | |
| Alopecia with crusted, inflamed, or ulcerated skin | Ectoparasites or dermatophytes |
| Bacterial opportunists such as Staphylococcus aureus | |
| Pruritic syndromes | |
| Dermal or subcutaneous masses | Tumors of skin or mammary origin |
| Lymphadenopathy | |
| Abscess, granuloma, cyst | |
| Nodular deformity of ears | Auricular chondritis |
| “Red” or “bloody” tears | Chromodacryorrhea caused by Harderian gland secretions (can also be seen on front paws and over the back from grooming) |
| Frequent clinical sign of coronaviral infection but can also be a nonspecific finding of illness or distress | |
| Circumferential, annular constrictions on tail | Ringtail (generally seen in suckling animals under conditions of low humidity and a cool or poorly insulated environment) |
| Head tilt, circling or spinning when lifted by tail | Bacterial or mycoplasmal otitis interna/media |
| Tumor or other space-occupying brain lesion | |
| Hairless, swollen, or bleeding plantar lesions | “Sore hock” syndrome associated with large and/or aged rats kept on wire or mesh flooring |
| Salivation, weight loss, swollen oral tissues | Malocclusion |
| Fecal staining | Diarrheal enteritis |
| Dyspnea/rales/hyperventilation | Mycoplasma pulmonis, Filobacterium rodentium (formerly CAR bacillus), Corynebacterium kutscheri, or Streptococcus pneumoniae infection |
| Overheating | |
| Facial swellings | Parotid and/or submandibular salivary gland swelling from coronavirus infection |
| Abscess of lymph nodes (lymphadenitis) | |
| Zymbal gland tumor at the base of the ear | |
| Abdominal distension (pot-bellied appearance) | Ascites |
| Intestinal distension from toxicity (chloral hydrate) | |
| Enteritis (possibly megaloileitis associated with Tyzzer's disease) | |
| Obesity | |
| Abdominal mass (tumor, abscess) | |
| Pregnancy | |
| Excessively wet hair coat and/or bedding | Diabetic polyuria |
| Leaking bottle or automatic water system | |
| Behavioral water wastage from “playing” | |
| Overheating | |
| Eye lesions | Blepharospasm, corneal opacities, keratitis due to coronaviral infection |
| Cataracts (aging lesion) |