[Endoparasites of donkeys and horses kept in communal housing in Upper Bavaria; species spectrum and incidence].

In this epidemiological study of endoparasites 37 donkeys and 23 horses were included, which were examined coproscopically in regular intervals over a 15 month period. The animals derived from ten farms, in which regular prophylactic treatments with anthelmintics had been practiced at least for two years before this investigation. This study revealed the presence of at least twelve parasite species in donkeys, Eimeria leuckarti, Gasterophilus intestinalis, Fasciola hepatica, Anoplocephala perfoliata, Strongyloides westeri, Parascaris equorum, Dictyocaulus arnfieldi, Trichostrongylus axei and small strongyles, whose third stage larvae were characterized by eight, twelve, 16 or 18 intestinal cells. At least four parasite species were established in horses, E. leuckarti, G. intestinalis, P. equorum and small strongyles, whose third stage larvae were provided with eight intestinal cells. Infections with E. leuckarti, S. westeri and P. equorum were encountered in foals only and with D. arnfieldi in 16.2% of the donkeys. Incidences for small strongyles were highest, exhibiting neither age- and farm-dependent nor host species-dependent differences and amounting to 91.9% in donkey and 86.6% in horses. Considering all donkeys and horses, 35.1% and 43.5%, respectively, were infected at least with two, and 29.7% and 4.3%, respectively, with three parasite species. The species composition of the endoparasite fauna was always dominated by small strongyles. This field study indicates that the species composition of the endoparasite fauna in comparison to former investigations has not or only slightly changed in spite of widespread use of broad-spectrum anthelmintics for years. In addition, it has to be considered that donkeys continue to act as reservoir of D. arnfieldi and as source of infection for horses.