Helminthoses of the digestive tract of sheep in the steppe zone of Transbaikalia

The infection of sheep with helminthiases of the digestive tract in the steppe zone of the Trans- Baikal Territory, the species composition of parasites and the degree of infestation by them were studied. Based on the results of complete helminthological dissections (PHV) and incomplete helminthological dissections (IGV), 20 species of helminths were collected and identified, of which 2 species belong to the cestode class and 18 species belong to the nematode class. The most common helminthiases are nematodirosis, ostertagiosis, trichostrongylosis, strongyloidiasis, and bunostomiasis, esophagostomiasis, and chabertiosis were found much less frequently. In some farms, strongyliasis of the digestive system is very widespread, affecting sheep with an extensiveness of invasion (EI) up to 96,7 %, and moniesiasis infects with EI up to 60,2 %.