Mad cow disease, bovine spongiform encephalopathy (BSE), is a cattle disease of the central nervous system. First identified in Britain in 1986, BSE is a transmissible spongiform encephalopathy (TSE), a disease characterized by the damage caused to the brain tissue. The tissue is pierced with small holes like a sponge. The disease is incurable, untreatable, and fatal. Researchers believe BSE is linked to Creutzfeldt-Jakob disease (CJD) in humans through the consumption of contaminated bovine products. CJD is a fatal illness marked by brain tissue deterioration and progressive degeneration of the central nervous system.