Resistance to anthelmintic (worming) drugs in livestock is a growing crisis that threatens the ability to control parasites causing significant welfare harm in sheep and cattle.
Anthelmintic resistance threatens to leave farmers without effective tools to control gastrointestinal parasites in livestock, potentially causing widespread welfare suffering. Parasitic gastroenteritis in lambs causes significant distress, weight loss, diarrhoea, anaemia and death. The welfare implications of resistance are serious: if effective drugs are no longer available, parasite burdens will increase. Responsible anthelmintic use - using drugs only when needed based on faecal egg count monitoring, rotating classes appropriately, and preserving refugia - slows resistance development and protects both welfare and the utility of treatments for future generations.