Possible role of domestic cats in the epidemiology of leishmaniasis: evidence of genital lesions and vertical transmission.

Feline leishmaniasis has been increasingly reported in countries endemic for zoonotic leishmaniasis, including Brazil, Spain, Italy, Portugal, and Israel, raising questions about the role of cats in disease transmission. Although dogs are the primary reservoirs, cats may contribute to the maintenance and spread of Leishmania spp. This study investigated genital lesions associated with feline leishmaniasis and explored the potential for vertical transmission. ELISA results showed seropositivity in 33.7% of females and 43.8% of males, while PCR on genital secretions was positive in 31.5% and 18.8%, respectively. Concordance between ELISA and PCR occurred in 33.3% of females and 7.1% of males. The most frequent genital lesions were endometritis in females and epididymitis or testicular degeneration in males. Epididymitis was significantly more frequent (p < 0.01) and more severe (p < 0.01) in seropositive males, while other lesions showed no significant association with infection. Among the four pregnant cats analyzed, one was seropositive and two were PCR-positive. Importantly, all carried at least one PCR-positive fetus (8/13; 61.5%), supporting the occurrence of vertical transmission. In conclusion, feline leishmaniasis is associated with genital lesions, particularly epididymitis in males, and may involve transplacental transmission. These findings strengthen the evidence that cats could play an epidemiological role in leishmaniasis and highlight the need for further investigation.