Ovine Eimeria infections in southern Brazil - prevalence and risk factors

Eimeria infections are common in sheep industry worldwide, however information about their epidemiology is scarce in southern state of Rio Grande do Sul, Brazil. Therefore, a cross-sectional study was carried out to determine the prevalence, species characterization, and associated risk factors between Eimeria species and sheep flocks. Fecal samples from 428 sheep from 21 farms were tested for the presence of oocysts. 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 (85.71%) was the most common, followed by Eimeria crandallis (80.95%), Eimeria granulosa (78.95%), Eimeria ahsata (61.90%), Eimeria faurei (42.86%), Eimeria bakuensis (38.10%), Eimeria punctata (14.29%), and Eimeria pallida (9.52%). 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). The wide distribution of this protozoan and the high frequency of pathogenic species show the importance and potential damage of coccidiosis in sheep flocks in Rio Grande do Sul.