Table 7.9.

Infectious Diseases of Rats

Pathogen	Common Names of Diseases	Fatal/Self-Limiting	Effects on Research
Parvovirus	Kilham rat virus; rat parvovirus	Asymptomatic	Immunomodulatory
Staph infection	Staphylococcus aureus	Dermatitis; septicemia	Significant clinical illness can result in necessity for euthanasia of the animal
Mycoplasmosis	Mycoplasma pulmonis Mycoplasma arthritidis Mycoplasma neurolyticum Mycoplasma collis	Rhinitis Otitis media Chronic pneumonia Infertility Can be fatal	Cause clinical disease Compromise experiments involving respiratory tract Alter immunological responses Contamination of cell lines and tumors
Cilia-associated respiratory (CAR) bacillus	Bacillus sp.	Respiratory disease Clinical disease—rare
Helicobacteriosis	Helicobacter hepaticus Helicobacter bilis, Helicobacter muridarum, Helicobacter rodentium, Helicobacter typhlonius	IC—asymptomatic IDS— inflammatory bowel disease, diarrhea, rectal prolapse	Affects liver enzymes in some strains of rats Morbidity and mortality in rats Alter immune function
Mycobacteriosis	Mycobacteria avium-intracellulare Mycobacteria leprae-murium	Granulomatous pneumonia and microgranulomas in other major organs	Morbidity
Pneumocystosis	Pneumocystis carinii	IC—asymptomatic IDS—severe disease; pneumonia May be fatal	Pneumonia in IDS rats; may be fatal
Nematodes (Mouse pinworms)	Syphacia obvelata Aspicularis tetraptera	Asymptomatic with gastrointestinal lesions such as enteritis and fecal impaction	Unthriftiness in mice Alter the immune responses in animal
Acariasis (Mite Infestation)	Myobia musculi Myocoptes musculinus Radfordia affinis	Skin lesions, excessive pruritus (scratching), hair loss, dermatitis	Disrupt immunological responses Severe clinical disease

IC, immune competent; IDS, immune compromised.