Chronic Wasting Disease is a fatal prion disease affecting deer populations in North America, with welfare implications and risk of spread to other continents.
Chronic Wasting Disease causes prolonged, progressive neurological deterioration in affected deer - a welfare tragedy affecting thousands of individual animals in North America. The disease follows a relentlessly negative trajectory: initial subtle changes in behaviour progress to obvious neurological impairment including staggering, loss of fear responses, difficulty swallowing, and severe weight loss before death. The extended incubation period means deer may carry the disease for up to two years before showing symptoms, during which time they spread prions through saliva, urine, and faeces. Management options for wildlife agencies are limited and often involve culling programmes to reduce transmission risk - creating a welfare dilemma where mass killing is justified on welfare grounds because it prevents the slower, more painful progression of the disease itself. The potential arrival of CWD in Europe would have significant consequences for deer welfare and management, and strict biosecurity around imported deer products is essential prevention.