U.S. probes mad cow report

The U.S. government is checking a possible case of mad cow disease in an animal previously cleared of being infected, the Agriculture Department said Friday.

Agriculture Secretary Mike Johanns said more tests were needed to confirm the disease, but he emphasized that the animal did not enter the food supply.

Only one case of mad cow disease has been confirmed in the U.S., in a dairy cow in Washington state in December 2003. Since then, preliminary tests have indicated the existence of the disease in three cows, but testing had ruled out mad cow disease.