Neoplastic and non-neoplastic diseases associated with feline leukaemia virus (FeLV) in cats in southern Brazil

The objective of this study was to categorise diseases associated with FeLV infection in cats. A total of 154 cats were submitted to necropsy, histopathology exam and anti-FeLV immunohistochemistry (IHC), and 83 (50.9 %) were IHC FeLV-positive. The cats age means of 4.1 years, including 3.6% kittens, 34.9 % junior, 37.4% prime, 18.1 % mature, 2.4 % senior, 3.6 % unknown age. Neoplastic diseases were most prevalent with leukaemia and lymphoma being most predominant, followed by viral diseases, bacterial, trauma, degenerative, intoxications, parasitic, malformation and others. FeLV+ cats were 5.73 times more likely to be diagnosed with neoplasms than other diseases. The odds ratio (OR) of FeLV+ cats developing leukaemia (OR = 7.75) and lymphoma (OR = 6.75) was higher than other neoplasms. FeLV infection was more prevalent in the mixed breed, junior to prime, male, with neoplastic diseases, including leukaemia and lymphoma. Therefore, understanding the diseases associated with FeLV is of paramount importance in Brazil due to its high prevalence, and it may encourage the implementation of prophylactic measures to reduce its dissemination.