1732: Scrapie, a fatal neurological disease that produces subacute spongiform encephalopathy in adult sheep, is first recorded. Similar disease occurs naturally in goats and captive mule deer and elk.
1794-1799: Disease called "the Rubbers'' is described in Young's Annals of Agriculture. Some flocks lose several hundred animals "from their seeming to rub themselves to death.''
1883: Case of scrapie in a cow reported by a French veterinarian.
1908: Meat and bone meal used in ruminant feeds; use of meat byproducts in animal feed is mentioned.
1920-1921: Hans-Gerhard Creutzfeldt and Alfons Mari Jakob, Austrian neurologists, each report cases of what become known as Creutzfeldt-Jakob disease, an incurable human brain-wasting disease.
1939-45: During Second World War, United Kingdom responds to food scarcity by advising use of non-food, industrial byproducts in compound feeds.
1945: Scrapie becomes reportable disease in Canada under federal Health of Animals Act. Scrapie was last diagnosed in goats in Canada in 1973.
1976: United States Department of Agriculture decides carcasses of sheep and goats with scrapie should not be used for human or animal food.
1985: First cow dies from "a novel progressive spongiform encephalopathy'' (CBE) in United Kingdom.
1986: Bovine spongiform encephalopathy (BSE) — commonly called mad cow disease — is first identified in the U.K. About 3.7 million cattle are slaughtered before disease is brought under control.
1996: Following BSE outbreak in Great Britain, European Union prohibits feeding rendered remains of any mammals to all food animals.
Source: The BSE Inquiry: The Report (Inquiry into BSE and variant CJD in the United Kingdom); Merck website