Scrapie

Scrapie is a disease of sheep and goats caused by a very small infectious agent. The agent is smaller than a virus and its exact identity is still unknown. The agent infects the central nervous system (brain) and, after a long incubation period (years) , affected animals show clinical signs of itching, incoordination, stumbling in the hind legs, head tremor, and weight loss. Although not all clinical signs are seen in every affected animal, the disease is ultimately fatal