Epidemiological and clinicopathological findings of feline immunodeficiency virus and feline leukemia virus infections in domestic cats from the Brazilian semiarid region.

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses of great importance for domestic cats with a worldwide distribution. A retrospective study was conducted to determine the epidemiological and clinicopathological aspects of the infection by FIV and FeLV in cats from the Brazilian semiarid region. Cats treated between 2011 and 2021 at the teaching veterinary hospital of the Federal Rural University of the Semi-Arid Region that were submitted to a point-of-care (POC) test to detect anti-FIV IgG antibodies and FeLV antigen were enrolled in the study. Overall, 454 cats were selected, of which 30.2% [95% CI = 26.0% - 34.3%] were FIV-positive, 1.1% [95% CI = 0.9% - 1.2%] were FeLV-positive, and 0.7% [95% CI = 0.1% - 1.3%] were coinfected by both retroviruses. No statistical association was found between the studied retroviruses (P = 0.144). Multivariable analysis detected significant associations between FIV infection and male sex [OR = 5.7, 95% CI = 3.0-10.7, P < 0.0001), age between 19 and 78 months [OR = 5.2, 95% CI = 2.2-12.1, P < 0.0001], age greater than 78 months [OR = 12.8, 95% CI = 5.1-31.9, P < 0.0001], crossbreed [OR = 4.1, 95% CI = 1.2-13.4, P = 0.021], the presence of oral disease [OR = 2.1, 95% CI = 1.3-3.4, P = 0.004], reduced red blood cell (RBC) count [OR = 3.7, 95% CI = 1.9-7.2, P < 0.0001], and an albumin:globulin (A:G) ratio lower than 0.6 [OR = 3.4, 95% CI = 1.6-7.1, P = 0.001]. No statistical analyses were performed for FeLV infection due to the low number of positive animals. In the quantitative analyses of hematological parameters, FIV-positive cats presented lower values for RBC, hemoglobin, hematocrit, lymphocytes, and platelets compared to the negative animals. In the biochemical profile, cats infected with FIV showed higher creatinine, urea, total protein, and globulin values, while lower values for albumin and A:G ratio were observed (P < 0.05). The findings of this study characterized the prevalence, clinicopathological findings, and risk factors associated with FIV and FeLV in cats from the Brazilian semiarid region. They may help support veterinary practitioners in diagnosing feline retroviruses. The FIV prevalence observed is among the highest reported in Brazil, demonstrating the need for prevention and control strategies for this retrovirus.