mad cow disease

mad cow disease A nickname for bovine spongiform encephalopathy (BSE), a progressive neurological disorder of cattle that results from infection by a transmissible agent. The most widely accepted theory is that the agent is a modified form of a normal cell surface component known as a prion. Evidence indicates that BSE has been transmitted to humans, primarily in the UK, causing a variant form of Creutzfeldt-Jakob disease (vCJD) and resulting in degenerative spongiform (soft and full of cavities, sponge-like) changes in the brain similar to those seen in affected cattle. Also known as bovine spongiform encephalopathy.