Prevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in ovine from São Paulo State, Brazil.

Serum samples from 597 sheep from São Paulo State, in the southeastern region of Brazil, were tested to determine the prevalence of antibodies directed against Toxoplasma gondii (> or = 1:64) and Neospora caninum (> or = 1:50) using the indirect fluorescent antibody test (IFAT). The animals were divided into three groups based on their age: < or = 1 year, 1-4 years, and > or = 4 years. Antibodies to T. gondii were observed in 34.7% of the samples with titers ranging from 64 to 16,384 and IgG antibodies directed against N. caninum were observed in 9.2%, with titers ranging from 50 to 3200. Only 3.5% of the sheep were positive for both agents. All farms had at least one positive animal for T. gondii, and 26 of the 30 farms had at least one positive animal for N. caninum. An association between seroprevalence and age was observed for T. gondii (P = 0.001), but not to N. caninum (P = 0.343). It was not possible to associate seroprevalence to T. gondii and the presence of domestic or feral cats, since in all farms there was at least one positive sheep. There was no association between seropositivity to N. caninum and the presence of domestic (P = 1.000) and feral dogs (P = 0.550).