Farm Animal Welfare

Cattle Anthelmintic Resistance and Strategic Worming

Anthelmintic resistance is growing in cattle worm populations, threatening the welfare tool kit available for parasite control.

Key Facts

Resistance to macrocyclic lactones and benzimidazoles is increasingly reported in cattle
Ostertagia ostertagi is the primary stomach worm affecting cattle welfare
Strategic use of anthelmintics rather than routine treatment is recommended
Faecal egg count monitoring guides targeted treatment decisions
Refugia-based management preserves susceptible worm populations

Welfare Considerations

Worm burden causes weight loss, ill thrift, diarrhoea, and reduced welfare in cattle. Growing anthelmintic resistance threatens the effectiveness of treatments that currently provide welfare protection. Strategic, evidence-based parasite management is needed to preserve drug efficacy while maintaining herd health - an approach that serves both welfare and sustainability goals.

What You Can Do

Support strategic worming training for cattle producers
Advocate for faecal egg count monitoring before treatment
Share guidance on refugia-based parasite management with farmers