Exposure of dogs and wild carnivores to canine distemper virus, canine parvovirus, Leishmania infantum, and Toxoplasma gondii in the Xingu River basin, Brazilian Amazon: Prevalence, spatial distribution, and association with land cover types

Infectious diseases transmitted by domestic dogs can have important consequences for wildlife health. This study aimed to investigate the exposure to four selected pathogens in dogs and wild carnivores in six municipalities in the Xingu River Basin (Pará state, Brazil). The prevalence of positive animals, their spatial distribution, and the association with land cover types were analyzed. Blood samples from 298 dogs and 11 free-ranging wild carnivores were tested through serological diagnoses. The seroprevalence to canine distemper virus, canine parvovirus, Leishmania infantum, and Toxoplasma gondii was 68.6, 75.4, 14.8, and 47.1%, respectively. The seroprevalence to canine distemper virus and T. gondii was significantly higher in dogs than in wild carnivores. Spatial analyses revealed a broad distribution of seropositive animals, except for animals seropositive to L. infantum, which were concentrated in the southern region close to the margins of the Xingu River. Spatial clusters of seropositive animals were detected for all tested pathogens, indicating areas with a greater risk of exposure. Positive results for canine distemper virus, T. gondii, and L. infantum were associated with different types of land cover, and thus were considered risk factors for pathogen exposure. The high seroprevalence of dogs to canine distemper virus and to canine parvovirus are concerning, suggesting risks of transmission to wild species inhabiting areas close to the surveyed communities.