TALLAHASSEE, FLA. (WPVI) -- Florida's Department of Agriculture announced today that a case of mad cow disease has been detected in a 6-year-old mixed breed beef cow.The department didn't say where the cow was, but emphasized that it never entered the slaughter channels or food supply.Mad cow is a progressive neurologic disease.This form of BSE (bovine spongiform encephalopathy) is not contagious, and is different from Classic BSE, which has been linked to variant Creutzfeldt-Jakob disease (vCJD) in people.Classic BSE occurred in the United Kingdom in the 1980s, in cattle which had been given the infectious prion agent, such as meat-and-bone meal containing protein from rendered infected cattle.The FDA has prohibited mammalian protein in feed for cattle since 1997, and in all animal feed since 2009.The animal in Florida was tested as part of the USDA routine surveillance of cattle deemed unsuitable for slaughter.