Sheep Scrapie Prion Disease and Welfare

Scrapie is a fatal prion disease of sheep and goats that causes progressive neurological degeneration over months, making affected animals a significant welfare concern in infected flocks.

Key Facts

Scrapie is caused by abnormal prion proteins that trigger a cascade of neurological destruction
It is one of the oldest known prion diseases, documented in sheep since the 18th century
Affected sheep show intense pruritus causing them to rub against fences and scrape off their wool
Progressive neurological signs include tremor, incoordination, and eventual recumbency
The disease is invariably fatal with an incubation period of 2-5 years
Genetic resistance to scrapie exists — sheep with the ARR/ARR genotype are highly resistant
EU-wide eradication programmes have used selective breeding for resistant genotypes to reduce incidence

Welfare Considerations

Scrapie causes prolonged suffering over months of progressive neurological decline. The intense pruritus driving the characteristic rubbing behaviour is genuinely distressing — affected sheep scrape themselves raw against any available surface. The progressive loss of motor coordination makes accessing food and water increasingly difficult. In the final stages, sheep become recumbent and cannot rise, developing secondary complications including pressure sores and starvation. Because the disease progresses slowly, there is a prolonged period of impaired welfare before death. Euthanasia when clinical signs are evident is the most welfare-positive intervention. Prevention through breeding for genetic resistance is the most ethical long-term approach.

What You Can Do

Work with your vet and flock health adviser to implement scrapie resistance breeding programmes
Cull clinically affected sheep humanely at first sign of neurological disease
Report suspected scrapie cases to your national veterinary authority as required by law
Support national scrapie eradication programmes that reduce flock-level disease prevalence
Maintain biosecurity when purchasing breeding sheep to avoid introducing scrapie to clean flocks