A prion is a membrane glycoprotein particle that lacks nucleic acid (DNA/RNA) and is hydrophobic. Prions have been found to be the source of several diseases such as scrapie in sheep, bovine spongiform encephalopathies (BSE), or mad cow disease in cattle, and chronic wasting disease in cervids. Prions are also the basis for human degenerative diseases such as Kuru and Creutzfeldt-Jakob disease. As a whole these diseases are referred to as transmissible spongiform encephalopathies, or TSEs. TSEs are characterized by a buildup of pathogens in the neurological tissue of animals.
Check out the web pages that my classmates have made for some of the mammals affected by prions.