Internal parasites are a major problem of Australian sheep. Anthelmintics have been the mainstay of sheep worm control, but their role is increasingly threatened by resistance in the target parasite species. There have been no enduring solutions to the problem of anthelmintic resistance, and the problem is getting worse.
One option, perhaps the only option, is to sidestep the problem by significantly reducing reliance on drug-based worm control. This Primefact discusses: