Anthelmintic resistance in sheep parasites is a growing welfare and sustainability crisis. Understanding resistance mechanisms and management strategies protects flock health long-term.
Anthelmintic resistance creates a long-term welfare crisis by gradually undermining the tools available to control gastrointestinal parasites that cause significant suffering. Haemonchus contortus infection causes severe anaemia and death from blood loss. As resistance spreads, farmers have fewer effective options to protect flock health. The short-term welfare of individual animals must be balanced against the long-term welfare of the flock and industry through stewardship practices that preserve drug efficacy. Sustainable parasite management protects future flock welfare by maintaining the tools needed to treat clinically important parasitism.