what causes mad cow disease and other such spongiform encephalopathies?
Bovine Spongiform Encephalopathy (BSE), or Mad Cow Disease. BSE (bovine spongiform encephalopathy) is a progressive neurological disorder of cattle that results from infection by an unusual transmissible agent called a prion. The nature of the transmissible agent is not well understood. Currently, the most accepted theory is that the agent is a modified form of a normal protein known as prion protein.