Anthelmintic resistance in sheep worms is a growing welfare and production crisis. Understanding sustainable parasite management protects sheep welfare without relying on failing drugs.
Sheep parasite management sits at a welfare crossroads — routine anthelmintic use is driving resistance that will eventually render available drugs ineffective, threatening the welfare of future flocks. The welfare consequences of inadequate parasite control are severe: Haemonchus-infested sheep can develop fatal anaemia within weeks. The transition to targeted selective treatment — treating only animals with high worm burdens rather than whole flocks — requires greater management skill and monitoring but preserves drug efficacy for when it is genuinely needed. This is not merely an economic efficiency question but a genuine welfare imperative: maintaining functional anthelmintics through sustainable use ensures they remain available to protect animal welfare in future. Genetic selection for parasite resistance offers the most sustainable long-term solution.