New data about the fauna of nematodes of Baruscapillaria genus have been obtained which show that they parasitize domestic geese in the Poltava region of the Ukraine. It has been established that the species composition of Capillariidae is represented by two species—B. anseris (Madsen, 1945, Moravec, 1982) and B. obsignata (Madsen, 1945, Moravec, 1982). For the first time in the Ukraine, parasitisation with non-specific geese species of Capillariidae family, B. obsignata, have been substantiated. It was found that capillariosis of geese was more frequent in the co-invasions of the birds’ digestive channel; the prevalence of invasion was 41.97 %. According to the results of helminthological dissection and identification of isolated pathogens, 40 varieties of co-invasions were found, where nematodes of the Baruscapillaria genus were combined with cestodes of two species: Drepanidotaenia lanceolata (Bloch, 1782) and Tschertkovilepis setigera (Froehlich, 1789), as well as with nematodes of four other species: Аmidostomum anseris (Zeder, 1800), Trichostrongylus tenuis (Mehlis, 1846), Heterakis gallinarum (Schrank, 1788) and Heterakis dispar (Schrank, 1790). Most often, we recorded capillariosis as a part of two- (prevalence—17.75 %) and three-component (11.75 %) co-invasions, and the main coexisting helminths of Capillariidae from Baruscapillaria genus were nematodes A. anseris (prevalence 22.78 %) and H. dispar (14.15 %).
