LAUSR

Introduction. Parasitic diseases are one of the main problems of horse breeding, in particular, helminthic infestations. The helminths are able to induce mechanical, toxic, inoculation effect. Moreover they absorb the nutrients necessary for the horse body. Thereby the helminths inflict significant harm on the horse population, not only due to animals deaths, but also due to weakening the protective functions of the body as well as working capability, sports and breeding qualities of horses. The aim of the present work is to study the epizootological aspects of helminthiases in horses at the territory of Tyumen region.Materials and methods. The study was carried out taking into account the horses keeping and care practices in twenty-two administrative districts of the region, located in the subzones of the northern and southern forest-and-steppe and subtaiga areas. To determine the infestation extensity (IE), the parasitological research methods of Kotelnikov-Khrenov, Fülleborn’s, Darling's modification method and the method of studying the scrapings of the perianal folds of the horse were applied. Results. During the research it has been found that the infestation extensity in horses infested with helminths in the Tyumen region averages to 27.9 ± 1.43 %. Whereas, the maximum helminthic infestation was found in horses in the subzone of the northern forest-and-steppe area IE 38.7 ± 1.97 % and the minimum in the subzone of the southern forest-and-steppe area IE 22.5 ± 1.16 %. It was found that in the conditions of year-round keeping in the stables with regular walking, the intestinal helminths parasitised in horses with the following infestation extensity (IE): Parascaris equorum 70.1 ± 2.53 %, suborder Strongylata 48.3 ± 1.97 %, Oxyuris equi 36.1 ± 1.63 %, the representative of Strongyloides westeri 20.9 ± 1.19 %. In the conditions of herd farming, the maximum infestation extensity in horses was observed for the helminths of suborder Strongylata with IE 74.0 ± 2.31 %, also spotted were parasites Parascaris equorum with IE of 41.2 ± 1.67 %, Oxyuris equi with IE — of 13.2 ± 0.87 % and the minimum infestation extensity was recorded for the parasites Strongyloides westeri with IE of 6.5 ± 0.21 %. In horses in the conditions of improved herd farming, the maximum infestation extensity was observed for the helminths of suborder Strongylata with IE of 79.4 ± 2.52 % and the minimum was for Strongyloides westeri with IE of 0.8 ± %. When studying the distribution of infestation in relation to the keeping and care practices, the data was obtained confirming that under practices of keeping in stables the helminths Parascaris equorum prevail with IE of 70.1 ± 2.53 % and under practices of herd and improved-herd farming the helminths of the suborder Strongylata with IE of 74.0 ± 2.31 % and IE 79.4 ± 2.52 %, respectively.Discussion and conclusions. Thus, in the result of studying the epizootic aspects of helminthiases in horses, it was found that helminthic infestation is recorded in various climatic zones throughout the whole territory of Tyumen region.