Long-acting anthelmintics - a study in Australia and New Zealand

Authors: Rolls N
Publication: Proceedings of the Australian Veterinary Association (AVA) Annual Conferences, Volume 2014 AVA Annual Conference, Perth, Issue Sheep / Industry, May 2014
Publisher: Australian Veterinary Association

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Abstract: The development of bolus anthelmintic delivery technology and novel chemistry has given sheep farmers the option of treating animals with long acting (LA) anthelmintic products prior to or during periods of high larval challenge or low immunity. The aim of these treatments is to control parasitic nematode infections present at time of treatment, prevent the establishment of new infections by killing incoming larvae and to significantly reduce the subsequent exposure of other sheep to incoming third stage infective larvae. This technology has been embraced by farmers in Australia and New Zealand such that LA products currently account for approximately 25% of the sheep drench market by value, largely associated with pre-lambing treatment of ewes. However, the major downside of treatment with LA products is that they are widely considered to be a high risk activity in terms of selection for anthelmintic resistance. 1 Over time this can have severe consequences for worm control on commercial sheep farms.

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