Resistance to ivermectin in a field strain of <i>Ostertugia</i> spp. in goats

Abstract

The occurrence of a field strain of Ostertagia spp. showing a resistance to ivermectin in Angora goats is reported. In a controlled anthelmintic trial using naturally-infected goats, ivermectin at a dose rate of 0.2 mg/kg demonstrated an efficacy of 87% against this strain.