Gastrointestinal nematodes remain a leading cause of welfare and production loss in sheep globally, with anthelmintic resistance now threatening the mainstays of parasite control.
Parasitic gastroenteritis causes significant and protracted suffering in sheep: affected animals show lethargy, bottle jaw from protein loss, reduced appetite, weight loss, and vulnerability to secondary infections. In acute Haemonchus infestation, anaemia develops rapidly and can be fatal. As anthelmintic resistance increasingly limits effective treatment options, farms face escalating welfare challenges. Targeted selective treatment, quarantine drenching of introduced stock, and integration of alternative strategies including copper oxide wire particles and bioactive forages represent the welfare-protective future for parasite management.