Scrapie

Scrapie, fatal disease of sheep and goats that attacks the central nervous system, causing deterioration of the brain cells. The deterioration leads to a characteristic staggering gait and other behavioral abnormalities, before death. Scrapie is caused by the presence of an abnormal version of the brain protein PrP and is related to bovine spongiform encephalopathy, the disease known as mad cow disease in cattle and Creutzfeldt–Jakob disease in humans. It is transmissible.

In 1996 Dutch researchers announced a test for detecting abnormal PrP in the tonsils of affected sheep before the symptoms of scrapie become apparent.