USDA still not coming clean on reasons for new mad cow tests

The U.S. Agriculture Department's inspector general is still not coming clean on why new tests were ordered unexpectedly on brain tissue from a cow declared free of mad cow disease seven months ago.

According to a statement released Wednesday by Inspector General Phyllis Fong's office, auditors noticed "an unusual pattern of conflicting test results" while reviewing the government's program of testing for mad cow disease.

Other than that there is no more information and apparently the audit findings will not be released until late summer.

The U.S. Agriculture Department said on Friday it is checking into a possible U.S. case of mad cow disease in an animal previously declared free of infection.

Although initial tests last November indicated the existence of the disease in the cow, subsequent tests had ruled out any infection.

The inspector general ordered a third round of tests last week, and the cow turned up positive.

A sample from the animal's brain is being sent to an internationally recognized laboratory in Weybridge, England, and the Agriculture Department will conduct further tests.

Apparently the cow did not present a threat to people or other animals. The department says it was a "downer" cow, one that is unable to walk, and downer cows are banned from the food supply.