Mad cow disease still posing a threat?

Despite the absence of mad cow disease for the last six years, an infected cow has been found in California. The farm that the cow belonged to said it wouldn’t have been a problem even if they had not found it because that cow was not going to be sold for the meat. Still, this poses a threat that mad cow disease may still cause problems. This was the fourth case of mad cow disease found in the United States. Authorities are working to dispose of the body by a method that will destroy the disease as well.

http://www.nytimes.com/2012/04/25/health/case-of-mad-cow-disease-is-found-in-us.html?_r=1&ref=science#