Host specificity of abomasal nematodes in free ranging alpine ruminants

Abomasums from 641 alpine wild ruminants representing five different specie s (Cervus elaphus, Capreolus capueolus, Rupicapra rupicapra, Capra ibex, Ov is musimon) and from 19 domestic sheep (Ovis aries) from alpine areas were examined in order to investigate the host-specificity of abomasal helminths . Nine out of 20 helminth species were found in at least five different hos t species. A discriminant analysis was able to significantly discriminate t he hosts on the basis of their helminth community composition with the exce ption of O. musimon and O. aries. Based on the correlation between each var iable represented by helminth species with the most explanatory discriminan t axis, it was possible to classify helminths into specialists and generali sts. Specialists are represented by the dominant species in a community of an host species or family while generalists appear in the communities of ma ny different hosts as intermediate species. Due to the pathogenic potential of some of these generalist species (i.e. Haemonchus contortus, Trichostuo ngylus axel) and their ability to adapt easily to the conditions found in s everal different hosts, they appear to be the most important from a sanitar y point of view. (C) 2000 Elsevier Science B.V. All rights reserved.