Opportunistic infections associated with retroviral infections in cats.

Naturally occurring infection of cats with feline leukemia virus and feline immunodeficiency virus is common. A wide variety of clinical manifestations occur in retrovirus-infected cats including gastrointestinal tract disease, respiratory tract disease, central nervous system disease, ophthalmic disease, hepatic disease, urogenital tract disease, dermatologic disease, hematologic disease, and musculoskeletal disease. Clinical signs are often directly attributable to the primary viral infection, but because both feline leukemia virus and feline immunodeficiency virus can induce immunodeficiency, opportunistic secondary infections may cause the clinical manifestations of disease in some cats. Diagnosis, treatment, and zoonotic potential of the common opportunistic agents associated with feline retroviral infections are reviewed.