Epidemiology of feline foamy virus and feline immunodeficiency virus infections in domestic and feral cats: a seroepidemiological study

Although foamy viruses (Spumaviruses) have repeatedly been isolated from bo th healthy and diseased cats, cattle, and primates, the primary mode of tra nsmission of those common viruses remains undefined. A database of the feli ne foamy virus (FeFV) and feline immunodeficiency virus (FN) antibody statu s, age, and sex of 389 domestic eats presented to veterinarians was assembl ed. A similar database for 66 feral (wild) cats was also assembled. That Fe FV antibody status reflects infection was validated by PCR Both FeFV and FN infection rates were found to gradually increase with age, and over 70% of cats older than 9 years mere seropositive for FeFV. In domestic cats, the prevalence of FeFV infection was similar in both sexes, In feral cats, FeFV infection was more prevalent in female cats than in male cats. Although bo th FeFV and FIV have been reported to he transmitted by biting, the pattern s of infection observed are more consistent with an interpretation that tra nsmission of these two retroviruses is not the same. The prevalence of FIV infection is highest in nondesexed male cats, the animals most likely to di splay aggressive behavior. The gradual increase in the proportion of FeFV-i nfected animals is consistent with transmission of foamy viruses by intimat e social contact between animals and less commonly by aggressive behavior.