Serosurvey for tick-borne diseases in dogs from the Eastern Amazon, Brazil Pesquisa Sorológica por doenças transmitidas por carrapatos em cães da Amazônia oriental, Brasil

Canine ehrlichiosis and babesiosis are the most prevalent tick-borne diseases in Brazilian dogs. Few studies have focused attention in surveying tick-borne diseases in the Brazilian Amazon region. A total of 129 blood samples were collected from dogs living in the Brazilian eastern Amazon. Seventy-two samples from dogs from rural areas of 19 municipalities and 57 samples from urban stray dogs from Santarém municipality were collected. Serum samples were submitted to Indirect Immunofluorescence Assay (IFA) with antigens of Babesia canis vogeli, Ehrlichia canis, and six Rickettsia species. The frequency of dogs containing anti-B. canis vogeli, anti-E. canis, and anti-Rickettsia spp. antibodies was 42.6%, 16.2%, and 31.7%, respectively. Anti-B. canis vogeli antibodies were detected in 59.6% of the urban dogs, and in 29.1% of the rural dogs (P < 0.05). For E. canis, seroprevalence was similar among urban (15.7%) and rural (16.6%) dogs. For Rickettsia spp., rural dogs presented significantly higher (P < 0.05) prevalence (40.3%) than urban animals (21.1%). This first study on tick-borne pathogens in dogs from the Brazilian eastern Amazon indicates that dogs are exposed to several agents, such as Babesia organisms, mostly in the urban area; Spotted Fever group Rickettsia organisms, mostly in the rural area; and Ehrlichia organisms, in dogs from both areas studied.Ehrliquiose canina e babesiose canina são as doenças parasitárias transmitidas por carrapatos de maior prevalência em cães do Brasil. Poucos estudos pesquisaram doenças transmitidas por carrapatos na região da Amazônia brasileira. Um total de 129 amostras de sangue foram colhidas de cães da Amazônia oriental brasileira. Setenta e dois cães eram de áreas rurais de 19 municípios do Estado do Pará, e 57 amostras foram colhidas de cães errantes vadios da área urbana do município de Santarém-PA. As amostras de soro foram submetidas ao ensaio de imunofluorescência indireta, com antígenos de Babesia canis vogeli, Ehrlichia canis, e seis espécies de Rickettsia. A frequência de cães com anticorpos anti-B. canis vogeli, anti-E. canis, e anti-Rickettsia spp. foi de 42,6%, 16,2% e 31,7%, respectivamente. Anticorpos anti-B. canis vogeli foram detectados em 59,6% dos cães urbanos, e em 29,1% dos cães rurais (P < 0.05). Para E. canis, a soroprevalência foi parecida entre os cães urbanos (15,7%) e rurais (16,6%). Para Rickettsia spp., cães rurais apresentaram prevalência (P < 0.05) significativamente maior (40,3%) do qu