Scrapie is a prion disease of sheep and goats causing progressive neurological deterioration and is invariably fatal, with welfare implications for affected animals and management challenges for affected flocks.
Scrapie causes progressive welfare deterioration as neurological signs advance: the intense pruritus that drives affected sheep to rub compulsively causes skin damage and distraction from normal grazing; incoordination impairs the ability to compete for food and water; and progressive neurological decline eventually renders affected animals unable to maintain themselves. Because there is no treatment and disease is invariably fatal, welfare management focuses on monitoring flocks for early signs, prompt identification of affected animals, and timely euthanasia before welfare deteriorates severely. Genetic selection for scrapie resistance is one of the most effective examples of preventive genetic welfare management in livestock, offering protection through breeding rather than through repeated intervention.