Sheep Scrapie: Prion Disease and Welfare

Scrapie is a fatal prion disease of sheep that causes progressive neurological deterioration and significant suffering. Genetic resistance breeding offers hope for eradication.

Key Facts

Scrapie has been present in sheep for over 250 years and is endemic in many countries
It is caused by misfolded prion proteins that destroy brain tissue progressively over months
Affected sheep show intense itching (hence the name — from scratching against fences), ataxia, and behavioral changes
The disease is invariably fatal — no treatment exists
Certain PrP gene variants (ARR/ARR genotype) confer near-complete resistance to classical scrapie
The EU's National Scrapie Plan mandates breeding for resistant genotypes to reduce flock prevalence

Welfare Considerations

Scrapie causes severe, prolonged suffering. The intense pruritus causes self-traumatization through rubbing; progressive ataxia makes walking painful and falls frequent; behavioral changes include anxiety and social withdrawal. The terminal phase involves recumbency, inability to eat or drink, and a slow death. Since there is no treatment, welfare management focuses on early identification and prompt humane euthanasia of affected animals. Genetic selection toward ARR/ARR genotypes is the only route to eradication and represents a major long-term welfare intervention.

What You Can Do

Farmers should implement genotype-based breeding selection using ARR/ARR rams
Euthanize suspected scrapie cases promptly — do not allow prolonged suffering
Report suspected scrapie cases to veterinary authorities for confirmatory testing
Support national scrapie eradication programs through compliance with breeding recommendations