Atypical scrapie in a sheep in a closed uk flock with endemic classical natural scrapie

NATURAL scrapie has affected sheep in Europe for at least 250 years ([Detwiler and Baylis 2003][1]) and its occurrence is now known to be associated with the PrP genotype of the sheep ([Hunter and others 1996][2]). The relative risk of scrapie for each genotype has been formalised in the National