Worms cost the Western Australian sheep industry up to $120 million every year, and anthelmintic (drench) resistant worms account for an increasing proportion of this amount. Resistant strains of sheep worms have been found on about 95 per cent of farms tested. This alarmingly high level indicates that all farmers should have a resistance management strategy which includes having a resistance test done on their farms before they drench their sheep. However, only about 20 per cent of farmers have had a resistance test done. Farmers often believe drench resistance is not a problem on their farms, mainly because production losses from the presence of resistant worms may not be obvious.
For maximum productivity and increased profits, farmers should incorporate a sheep worm control programme that includes a resistance management strategy based on a resistance test and periodic faecal worm egg counts into their sheep management programme
"New approach to control of drench-resistant sheep worms on farms,"
Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 31
, Article 5.
Available at: http://researchlibrary.agric.wa.gov.au/journal_agriculture4/vol31/iss3/5