A neurodegenerative disease found in domestic cattle which is related to a number of other similar diseases found in other animal species, including humans.
The most well-known of these other diseases are scrapie, found in sheep, and Creutzfeldt-Jakob Disease, found in humans. The family of diseases is caused by an abnormally-configured protein called a prion. The function of the protein in its normal configuration is not certain. The diseases are similar to Alzheimer's disease in humans, except the progressive loss of brain function is more rapid.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.