WASHINGTON – A second American animal has tested positive for mad cow disease, Agriculture Department officials said Friday night. The sample, from a downer cow in Texas that died last November, was retested earlier this week at the request of the USDA inspector general’s office.
The animal had been deemed disease-free last fall, but when a sample was subjected to a more precise test, the result a “weak positive,” according to USDA Secretary Mike Johanns. He said that because of the differing results from the two tests, the sample would be sent next week to the world’s top mad cow lab in Weybridge, England, for a final set of testing.
Johanns said repeatedly Friday night that the new result did not mean that people face any greater health risk from eating beef because meat from the animal did not enter the human food chain, or the beef feed chain. He also said the result should not have an impact on long and difficult negotiations under way to resume the exporting U.S. beef to Japan and Korea, or the re-opening of the Canadian border to live cattle.
But if the positive finding is confirmed in England, the international reaction against U.S. beef that occurred when a Mabton, Wash., dairy cow tested positive in 2003 could be repeated.
While the first U.S. mad cow case involved an animal born and raised largely in Canada and then shipped to Washington state, USDA chief veterinarian John Clifford said Friday night that the agency had “no information” that the possible second case was “an imported animal.” He said the Texas animal was a beef cattle and was older but declined to give any more specifics.
He did not indicate, for instance, whether the animal was born before or after the United States implemented a ban on feeding animal parts to cows in 1997. Mad cow infection is only known to spread through the consumption of beef parts that were fed to some cows in the 1990s, and the 1997 feed ban was designed to keep mad cow disease from spreading through the U.S. herd.
The three Canadian animals that have tested positive for mad cow disease, as well as the Washington state animal, were all found to have been born prior to the feed ban.
Over the past year, the USDA has tested about 375,000 animals as part of an enhanced surveillance program and had found only three inconclusive results, Johanns said.