A MODEL TRANSMISSION OF ANTHELMINTIC RESISTANT NEMATODES BY WILD RUMINANTS

The experiment was carried out to demonstrate a possible role of wild ruminants in spreading anthelmintic resistant nematodes between flocks of sheep and/or goats. A benzimidazole resistant strain of Haemonchus contortus, originally isolated from sheep in the USA, was passaged th rough three mouflons (Ovis musimon) and subsequently used to infect tw o worm-free lambs. As the parasite isolate was passaged, the level of its benzimidazole resistance was estimated using an egg hatch assay in all used hosts: sheep, mouflons and lambs. The level of ED(50) did no t change significantly, ranging from 0.69 to 0.8 mu g.ml(-1).