Mad cow disease is caused by a prion. a prion is a malformed protein that is found in the brain tissue of infected cows, and exposure can be fatal. meat that comes in contact with infected tissue becomes contaminated with the prion. currently, there are no treatments for prion diseases because prions are hard to target and are too similar to normal proteins. to prevent the disease, scientists would most likely recommend that people avoid eating meat entirely. new medicines be developed to prevent infection. people avoid travel in countries where the disease is common. meat handlers keep brain tissue from coming in contact with other meat.