ABSTRACT:
The objective was to evaluate the occurrence, clinical signs and risk factors associated with seropositivity to Toxoplasma gondii and Neospora caninum in sheep. We used 294 sheep with history of reproductive disorders from 28 farms located in the state of São Paulo, southeastern Brazil. Producers were interviewed, and blood samples were collected to perform indirect immunofluorescence tests (1:64 and 1:50 respectively). The frequency of T. gondii infection was found to be 29.9% (88/294), the frequency of N. caninum was 18% (53/294), and 3.7% (11/294) of the sheep were seropositive for both. We observed the following risk factors associated with T. gondii infection: crossbred sheep (p=0.04), Santa Inês breed (p=0.006), pasture supply (p<0.001) or associated with concentrate (p<0.001), exclusive use of natural breeding (p=0.002), and presence of birds on farms (p=0.001). For N. caninum the factors were: female sheep (p=0.031), absence of barns (p<0.001), and semi-intensive system (p<0.001). In relation to the history of reproductive problems, N. caninum and T. gondii infected sheep presented a reduction in the risk of having an abortion (p=0.044) and repeated estrus (p=0.025) respectively. T. gondii was more serologically present than N. caninum in sheep with a history of reproductive disorders and, despite their similarities, differed epidemiologically in aspects related to breeding characteristics such as race, sex, breeding system, type of feeding and reproductive management.
INDEX TERMS:
Antibodies; anti-Toxoplasma gondii; anti-Neospora caninum; risk factors; sheep; reproductive disorders; abortion; toxoplasmosis; neosporosis; repeat breading; parasitoses