By Kathryn McConnell
Washington File Staff Writer

Washington - A beef cow in the United States has tested positive for bovine spongiform encephalopathy (BSE), or mad cow disease, according to the U.S. Department of Agriculture (USDA).

No parts of the cow entered the human or animal food chain, John Clifford, chief veterinarian of USDA's Animal and Plant Health Inspection Service (APHIS), told reporters March 13.

As APHIS' investigation goes on, "we will continue to be very transparent in sharing information with the public and with our trading partners around the world," Clifford said.

He said USDA does not expect U.S. beef exports to be affected.

An inconclusive result of a March 10 routine test on a 10-year-old, nonambulatory cow in the state of Alabama indicated the presence of the disease. That result then was confirmed by the USDA National Veterinary Services Laboratories in Iowa.

APHIS is doing a third type of test, known as immunohistochemistry, and plans to release those results within days, Clifford said.

The agency is investigating the origin of the cow and of the herds with which it was raised. After a veterinarian took tissue samples from the ailing cow, the animal was euthanized and buried on the farm where it had lived for less than a year. The cow was born before 1997 - prior to the U.S. ban on feed containing bovine-derived material. That ban was designed to limit the spread of BSE in cattle.

All animals determined to have come into contact with the infected cow will be tested for BSE, Clifford said. However, worldwide experience has shown that it is "highly unusual" to find BSE in more than one animal in a herd or in an infected animal’s offspring, he added.

This is the third case of BSE found in the United States since an enhanced surveillance program was put into place in mid-1994.

The surveillance program involves a "system of interlocking safeguards" intended to ensure that any cases of BSE are identified and contained quickly and accurately.

Since the surveillance program began, approximately 650,000 cows have been tested for the disease, said Jim Rodgers, an APHIS spokesman.

The science-based surveillance program is in accordance with standards from the World Organization for Animal Health, and Clifford urged other countries to join the United States and base their BSE-testing procedures on these standards.

The full text of Clifford’s statement is available on the USDA Web site.