Leptospira Infections in Cats—What Do We Know?

The incidence of Leptospira spp. infections in cats did not seem to be of major importance until the early 21st century. The relatively rare occurrence of individuals presenting antibodies against Leptospira spp. and the almost unheard of clinical cases appeared to suggest that felids are poorly prone to Leptospira infections. Considering the close contact of cats with rodents (mice, rats, etc.), which are the main reservoir of leptospires, the above observations may, on the one hand, be surprising, but on the other hand, may reflect species-specific biological or ecological factors influencing susceptibility, although the underlying mechanisms remain poorly understood. The suspicions indicating cats as incidental hosts or asymptomatic carriers of Leptospira spp., their proximity to humans, and the “One Health” approach—particularly relevant recently in control of zoonoses—contributed in recent decades to greater research interest in feline leptospiral infections. Recent increasingly frequent data on the occurrence of antileptospiral antibodies in cats, cases of isolation of leptospiral DNA or viable spirochetes from blood or urine samples, and finally cases of clinical disease may support these hypotheses, although the available evidence remains limited and warrants further investigation. This review presents the current data on the incidence and pathogenesis of infections caused by Leptospira spp. in cats and their potential epidemiological role, including their possible contribution to environmental contamination and zoonotic transmission.