Prevalência e fatores de risco associados à infecção por Eimeria spp. em ovinos no sul do Brasil

Abstract

Traditionally, the sheep industry has always been relevant to the economy of the Rio Grande do Sul state, Brazil. However, in last decades sheep farming has declined in the area. Among the main obstacles for sheep farming to become commercially viable, parasitic problems stand out. Epidemiology data of Eimeria spp. infection in the state are scarce. This protozoan interferes with animal growth and weight gain, and can cause diarrhea, anorexia, weakness and underdevelopment, especially in young sheep. Therefore, a cross-sectional study was carried out to report epidemiological data of Eimeria spp. infections in sheep from southern Rio Grande do Sul, Brazil. Fecal samples from 502 sheep were tested for the presence of oocysts. 21 farms located in 11 municipalities were included in the study A structured questionnaire was administered, to assess the knowledge of sheep health and husbandry and farm management practices, this information was used to search for risk factors associated with Eimeria infection. The overall prevalence of Eimeria spp. was 68.69% and was significantly affected by age of the sheep, with highest prevalence in animals under 18 months of age. Eight Eimeria species were identified. Eimeria ovinoidalis was the most common, followed by Eimeria crandallis, Eimeria granulosa, Eimeria ahsata, Eimeria faurei, Eimeria bakuensis, Eimeria punctata and Eimeria pallida. All herds were positive, with concomitant infections. Among management and husbandry practices; farm size, animal density, farming system, breeding objectives, and pasture system influenced the prevalence of Eimeria species. The infection was more prevalent on small farms with high animal density, in sheep raised for meat, semi-intensive system, and rotational grazing (p < 0.05). This research describes for the first time the occurrence of E. crandallis and E. ovinoidalis in the study area. These results show the importance and potential damage of coccidiosis in sheep flocks in Rio Grande do Sul.