Feline Leukemia Virus in Free-ranging Neotropical Wild Felids and in Domestic Cats Found Inside Protected Areas...

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses that cause severe diseases in domestic cats. Recently, they have emerged as a concern for wild felids. The aim of this study was to evaluate the exposure to feline retroviruses in free-ranging Neotropical wild felids from southern Brazil. A total of 48 road-killed wild felids belonging to three species were sampled: Geoffroy's cat (Leopardus geoffroyi), margay (Leopardus wiedii), and Southern tiger cat (Leopardus guttulus). In addition, 28 domestic cats found inside protected areas were investigated. Both the wild and domestic felids were tested for the presence of FeLV and FIV with lateral flow immunoassay (LFA) and molecular methods. Three wild felids (two Geoffroy's cats and one margay) were positive to FeLV by LFA (antigen), PCR (proviral DNA), and quantitative reverse-transcription PCR (viral RNA). From the 28 free-roaming domestic cats sampled inside protected areas, 10 (35%) were positive for FeLV. None of the domestic or wild felids were positive for FIV. In addition to the occurrence of FeLV in two species of free-ranging Neotropical felids, FeLV-positive domestic cats appear to be relatively common in protected areas from southern Brazil, posing an important risk of FeLV transmission to threatened wild felids inside those areas.