Farm Animal Welfare

Sheep Welfare and Internal Parasite Resistance

Anthelmintic resistance in sheep nematode parasites is a major and growing welfare and production challenge. Targeted selective treatment programmes preserve drug efficacy.

Key Facts

Resistance to multiple anthelmintic drug classes is widespread in UK sheep nematodes
Blanket treatment of whole flocks is a key driver of resistance development
Targeted selective treatment (TST) uses FAMACHA and body condition to identify treatment-priority individuals
Refugia - maintaining susceptible worm populations - slows resistance development
Genetic selection for worm resistance reduces treatment need in some breeds

Welfare Considerations

Anthelmintic resistance threatens long-term worm control, creating welfare vulnerability as drug options narrow. Responsible use through TST programmes preserves efficacy and maintains welfare protection.

What You Can Do

Work with your vet to implement targeted selective treatment programmes
Seek faecal egg count monitoring to guide treatment decisions
Learn about anthelmintic resistance and refugia management
Support research into alternative parasite control strategies