Seropositivity for Pathogenic Leptospira in Dogs, Cats, and Horses at a Teaching Veterinary Hospital in Southern Chile

At a veterinary hospital in southern Chile, we conducted an epidemiological study involving domestic dogs, cats, and horses to determine the seropositivity for pathogenic Leptospira spp., identify the infecting serogroups, measure antibody titers, and characterize seropositive animals by sex and age. None of the sampled animals showed clinical signs of leptospirosis. The microscopic agglutination test, using a panel of eight serogroups, was used for diagnosis. The seropositivity was 36.5% (95% confidence interval [CI] = 24.5–48.4) in dogs, 12.9% (95% CI = 2.6–23.1) in cats, and 45.2% (95% CI = 30.1–60.2) in horses. Serological reactions were detected for the Tarassovi and Canicola serogroups in dogs, Sejroe, Canicola, Icterohaemorrhagiae, and Grippotyphosa in horses, and Tarassovi in cats. The most frequent antibody titers were 1:200 and 1:400 in dogs, 1:400 in cats, and 1:800 in horses. The distribution of seropositivity varied by sex and age across different animal species. The seropositivity for pathogenic Leptospira in dogs, cats, and horses attending a veterinary hospital underscores the role of domestic animals as sentinels for zoonotic diseases. This finding has implications for epidemiological surveillance systems in increasing awareness of seropositivity and establishing specific prevention measures to mitigate the risk of leptospirosis transmission.