Sheep and Deer Deer Deworming Welfare

Parasite control in sheep and deer involves significant welfare considerations, with both the welfare harm of parasite burden and the welfare impact of treatment methods requiring careful management.

Key Facts

Gastrointestinal nematodes are the most economically significant disease of sheep in the UK, causing weight loss, diarrhoea and death
Anthelmintic resistance is a growing problem in sheep parasites, with resistance to three of four drug classes documented in the UK
Targeted selective treatment rather than routine whole-flock treatment reduces resistance development and treats only animals that need it
SCOPS (Sustainable Control of Parasites in Sheep) provides evidence-based guidance on integrated parasite management
Liver fluke, carried by freshwater snails, causes significant welfare harm and mortality in sheep on wet land

Welfare Considerations

Sheep parasite welfare involves balancing the harm caused by parasites against the harm caused by treatments. Untreated heavy parasite burdens cause chronic weight loss, nutrient malabsorption, anaemia, diarrhoea and death — significant welfare harms. However, routine whole-flock anthelmintic treatment regardless of individual parasite burden drives resistance, reducing the effectiveness of treatments in future — a long-term welfare harm. Targeted selective treatment based on faecal egg counts and clinical assessment treats animals that need treatment while preserving drug efficacy. This welfare-positive approach is also economically beneficial, reducing treatment costs and maintaining tools that will be needed in future.

What You Can Do

Support farms using targeted selective treatment approaches through purchasing certified welfare-conscious lamb
Engage with SCOPS guidance and share it with sheep farming contacts at www.scops.org.uk
Advocate for veterinary training in integrated parasite management to be standard in sheep health planning
Support research into anthelmintic alternatives including vaccines and biological control methods
Engage with the long-term welfare implications of anthelmintic resistance for future sheep farming