The rapid appearance of anthelmintic resistance on a sheep farm

Authors: Probert AD, West DM
Publication: New Zealand Veterinary Journal, Volume 37, Issue 3, pp 126-127, Sep 1989
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Alimentary system/gastroenterology, Anthelmintics, Parasite control, Parasites - internal, Animal remedies/veterinary medicines, Nematode, Treatment/therapy
Article class: Correspondence

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Abstract: Anthelmintic resistance has been reported with increasing frequency in New Zealand sheep and the following case highlights how quickly this can develop in a flock. In March 1988 an egg count depression test conducted by Dr. A.R. Butler indicated that drenches from three action families: ivermectin, levamisole and oxfendazole, were effective on this farm. There was some concern about the efficacy of oxfendazole against Nematodirus spp., but the pretreatment counts were too low to establish a diagnosis of resistance…

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