Journal of the Department of Agriculture, Western Australia, Series 4


Sheep, Helminths, Anthelmintics, Drug resistance, Surveys, Western Australia

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The Department of Agriculture launched the CRACK approach to worm control in September 1985 in response to finding that anthelmintic (drench) resistant worms were present on 68 per cent of a random selection of Western Australian sheep farms.

The high cost of internal parasites in terms of lost production and drench costs, together with the high prevalence of resistant worms of farms, confirmed that changes were needed to existing parasite control measures in sheep.l