Seroprevalence of pathogenic leptospira in domiciled and stray dogs from subtropical Mexico

Leptospirosis is a zoonotic bacterial disease of public health concern. Dogs are hosts that can carry and eliminate diverse serovars of Leptospira for long periods. Available vaccines can protect against only two to four serovars of Leptospira, and some additional virulent serovars not included in the vaccines may circulate in the environment. The objective of this study was to estimate the seroprevalence of circulating Leptospiras in owned vaccinated, owned unvaccinated, and stray dogs, and to assess the risk factors associated with the presence of antibodies. Owned vaccinated, and owned unvaccinated dogs were selected, which were randomly recruited from different veterinary clinics, and a questionnaire was given to their owners to obtain their background; samples from stray dogs were obtained from the animal control center of the municipality of Merida. The MAT test against 11 serovars was used. A total of 335 samples were obtained, 215 from domiciled dogs and 120 from stray dogs. The seroprevalence was 34.02% (33/97) in vaccinated domiciled dogs, 38.98% (46/118) in nonvaccinated domiciled dogs and 39.16% (47/120) in stray dogs. The main serovars found were Australis, Bratislava, Autumnalis, and Pyrogenes in the three groups of dogs. A high seroprevalence of Leptospira spp. was detected in all groups of evaluated dogs including pathogenic serovars not serovars not contained in the commercial vaccines; since no relevant risk factors were detected all pet and stray dogs are at the same risk to become in contact with pathogenic leptospiras.