[2] Following the identification of Bovine Spongiform Encephalopathy (BSE) in the Canadian cattle herd in May 2003, exports of beef from Canada were shut down worldwide, including to Korea. (asiapacific.ca)
Degenerative brain diseases like mad cow disease (officially known as bovine spongiform encephalopathy, or BSE), scrapie in sheep, and vCJD in humans are thought to be caused by prions, misfolded versions of a normal cellular protein called PrPC. (sciencemag.org)
The disease is part of a group known as transmissible spongiform encephalopathies, which includes mad cow and a few other rare diseases. (sciencedaily.com)