Re: Ivermectin-resistant Ostertagia circumcinta from sheep in the lower North Island and their susceptibility to other macrocyclic lactone anthelmintics

Abstract

Extract

Leathwick et al (2000) examined the efficacy of 3 macrocyclic lactone anthelmintics against a 23-day-old infection with an ivermectin-resistant strain of Ostertagia circumcincta. The efficacy of moxidectin against this strain was 99.9–100%. The efficacy of abamectin, at 92–96%, was higher than the efficacy of ivermectin but less than that of moxidectin.