Scrapie is a serious disease of sheep, and sometimes goats. The animal becomes restless, loses weight, and — this is how the name came — rubs and scrapes its body against walls, fences, and posts because the skin and nerves feel wrong. There is no simple cure; sick animals are usually killed so the rest of the flock stays safer. It belongs to the same group of brain diseases as mad cow disease in cattle: a wrongly shaped protein in the brain, not an ordinary germ you treat with medicine. You will meet the word in farming and animal-doctor English, almost never in daily chat. People do not casually catch scrapie from a lamb dinner the way the mad-cow scare made everyone worry about beef, though scientists have watched this family of diseases very carefully for years.

羊搔癢症