Leptospirosis is an emerging zoonotic disease of worldwide distribution. A cross-sectional study was conducted in urban and rural environments in southern Chile (1) to detect domestic cats with serologic evidence of exposure to Leptospira spp.; (2) to determine the prevalence of anti-Leptospira antibodies; (3) to describe seroprevalences according to different characteristics of the animals, and (4) to identify risk factors associated with the seropositivity in the Microscopic Agglutination Test (MAT). Blood samples were taken from 124 owned cats. A frequentist and Bayesian approach were applied for prevalence estimation. The overall apparent prevalence of anti-Leptospira antibodies was 8.1% (95% Confident Interval = 3.9–4.3). With the Bayesian approach, the overall True Prevalence (TP) was 5.2% (95% Credibility Interval (CrI) = 0.6–12.4). The TP for urban cats was 1.8% (95% CrI = 0.1–7.2) and the TP for rural felines was 25.2% (95% CrI = 9.3–46.6). Cats that live in a place where agricultural activities are performed with water that flows in streams or backwater and cats that live in places near flooded areas had a higher risk of seropositivity in MAT. The exposure to Leptospira spp. in domestic cats of urban and rural origin in Southern Chile is a public health concern that requires an increased awareness and the implementation of preventive measures.

A cross-sectional study using 99 serum samples of dogs from southern Chile was conducted to determine the diagnostic utility of a rapid immunochromatography assay for the detection of Leptospira specific IgM antibodies as screening test and as a potential aid in the diagnosis of leptospirosis in animals with and without clinical suspicion of the disease. The Microscopic Agglutination Test (MAT) was used as reference assay. Anti-Leptospira antibodies were detected in 37.3% of the dogs with MAT. Using the immunochromatography test, specific IgM antibodies were found in 13.1% of sampled dogs. The sensitivity of the rapid test as screening assay was 29.7% (95% Confidence Interval=16.4-47.2) and the specificity was 96.7% (95% Confidence Interval=87.8-99.4). 40.0% of the canines with clinical suspicion of leptospirosis and 37.1% of dogs without clinical signs were serological reactors to MAT, but none of MAT reactive dogs with clinical suspicion tested positive in the rapid test. Rapid and user-friendly diagnostic procedures for canine leptospirosis such as this immunochromatography assay could be important tools to use in clinical practice, however, further studies are needed to obtain more information about their utility, considering that diagnostic tests could not have similar performances in different geographic locations, clinical and epidemiological contexts.