Canine visceral leishmaniosis (CVL) may be an important factor preceding human outbreaks of the disease. We report that the prevalence of canine visceral leishmaniosis infection has been increasing in recent years in Anastácio town, located in the central western region of Brazil. Serological investigations showed that 75.3% of dogs presented antibody titres ranging from 1/40 to 1/160 in the indirect immunofluorescence antibody test (IFAT). Bone marrow and lymph node aspirates provided positive cultures and furnished parasites for enzymological and serological typing in 42.5% and 41.1% of the cases, respectively. All the strains were typed as Leishmania (L.) chagasi. This is primarily a canine disease that spills over into the human population as a zoonosis. The study showed the epidemiological features of the infection in a region in which the problem of visceral leishmaniosis has been underestimated.