Triple anthelmintic resistance in Trichostrongylus spp. in a German sheep flock

Multiple anthelmintic resistance in small ruminant nematodes is widespread in some overseas and tropical countries but is a relatively new problem in Europe. A population of Trichostrongylus spp. 100% resistant to ivermectin and albendazole and partially resistant to levamisole was identified in a Dorper sheep flock in Southern Germany using a faecal egg count reduction test and larval cultures. This is the first reported case of triple anthelmintic resistance in small ruminant gastrointestinal nematodes in Germany.