ABSTRACT. Cordeiro M.D., de Meireles G.S., da Silva J.B., de Souza M.M.S. & da Fonseca A.H. [Seroprevalence for Borrelia spp. in dogs at the Municipality of Seropédica in the State of Rio de Janeiro]. Soroprevalência para Borrelia spp. em cães no município de Seropédica, estado do Rio de Janeiro. Revista Brasileira de Medicina Veterinária, 34(3):251-256, 2012. Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465 km 7 Seropédica, RJ 23890-000, Brasil. E-mail: firstname.lastname@example.org This study aimed to verify the presence of IgG antibodies against Borrelia burgdorferi in stray and domiciled dogs from municipality of Seropédica, RJ. Blood was collect from 293 dogs in four areas of the municipality of Seropédica-RJ. Serum samples were analyzed through of the indirect enzyme-linked immunosorbent assay (ELISA), using crude antigens of B. burgdorferi G39/40 strain from North America. To confirm the presence of anti-Borrelia spp. antibodies, 102 positive samples were tested by Western Blotting (WB). Ticks were also collected through of inspection of the animals. The specimens were manually removed and stored in polypropylene bottles and later identified. The association between seropositive animals and variables were performed using the χ2. Of the 293 sera tested, 154 (52.56%) were positive for homologous antibodies anti-B. burgdorferi. It was found a prevalence of 43.75% (14/32) in “54 km”, 51.72% (45/87) in “49 km”, 46.67% (42/90) in “40 km” and 63.1% (53/84) in Universidade Federal Rural do Rio de Janeiro (UFRRJ) campus. Significant difference was observed between the prevalence of dogs from UFRRJ campus and Seropédica urban areas. The group of dogs over two years old had greater frequency of positive animals (p <0.05). There were no statistical differences (p> 0.05) between the variables: presence of ticks, animal sex, habits, frequenting pastures and age of the animals. At least 64.5% (189/293) dogs were infested with ticks at the moment of collection. Only Rhipicephalus sanguineus and Amblyomma cajennense were identified. Of the 102 samples tested by WB as a confirmatory test, 85.29% (87/102) had at least five of the ten specific bands. The presence of antibodies anti-B. burgdorferi in dogs from Seropédica is an indicative of the presence of spirochetes in dogs.