Distribution of helminths of the gastrointestinal tract of horses in Central Altai

The results of the studies (2021, 2022) on the spread of helminth infectious agents in horse breeding farms are presented. Parasitic worms of two classes Nematoda and Cestoda participate in the formation of the helminthic complex of Central Altai animals. Nematodes of two suborders Strongylata and Ascaridata (Parascaris equorum) were recorded. Two species Anoplocephalaperfoliata and Paranoplocephalamamillana were identified in cestodes represented by the tapeworms of suborder Anoplocephalata. In the province (87.8%) and in some administrative districts, infestation of whole-hoofed animals with gastrointestinal strongylates is much higher than infection with helminthes of suborder Ascaridata (14.1%) and cestodes of suborder Anoplocephalata (10.9%). Nematodes of suborder Strongylata play the main role in forming the nosological profile of intestinal helminth infections. Strongylates form the core of the helminthocomplex of the digestive system, and the infestation of whole-hoofed animals with them and their share in the structure of the helminthocomplex both in the province and in individual administrative districts is the highest. The values of IP (invasion prevalence) and PCI (parasite complex index) of strongyloides vary by administrative regions from 53,3 and 69,1% to 95,2 and 80,8%, respectively, and amount to 87,8 and 77,8% on average in the Central Altai. It was found that in most areas, the infestation of whole-hoofed animals with helminths of the digestive system in general and nematodes of suborder Strongylata diﬀers insignificantly. Infestation of whole-hoofed animals by Parascaris equorum and cestodes of suborder Anoplocephalata is registered in the region at 14,1 and 10,9% with PCI 12,5 and 9,7 respectively, which is 6-8 times lower than analogous indices for strongylatosis of animals. Reliable direct correlation between the release of strongylate eggs into the external environment and the index of animal infestation was established. The number of propagative forms released into the environment increases with increasing values of animal infestation with strongylates.