The first-ever U.S. case of mad cow disease is suspected in a single cow in Washington state, but the American food supply is safe, Agriculture Secretary Ann Veneman said Tuesday.
"We remain confident in the safety of our food supply," said Veneman.
She told a news conference that a single Holstein cow that was either sick or injured -- thus never destined for the U.S. food supply -- tested presumptively positive for the brain-wasting illness.
Mad cow disease, known also as bovine spongiform encephalopathy, is a disease that eats holes in the brains of cattle. It sprang up in Britain in 1986 and spread through countries in Europe and Asia, prompting massive destruction of herds and decimating the European beef industry.
"This incident is not terrorist-related," Veneman said Tuesday. "I cannot stress this point strongly enough."
Veneman said the apparently diseased cow was found at a farm in Mabton, Wash., about 40 miles southeast of Yakima. She said the farm has been quarantined.
"Even though the risk to human health is minimal, we will take all appropriate actions out of an abundance of caution," she said.
Samples from the cow have been sent to Britain for confirmation of the preliminary mad cow finding, she said.
Mad cow disease has never been found in the United States before this incident despite intensive testing for it.
However, there was a case of mad cow disease in Canada last May that officials described as a single, isolated incident.
Veneman said a tissue sample from the suspect U.S. cow was taken on Dec. 9 and had been tested at a lab in Ames, Iowa.
She said the Agriculture Department has had safeguards in place since 1990 to check for mad cow disease and that 20,526 cows had been tested in 2003 in the United States.
"This is a clear indication that our surveillance and detection program is working," Veneman said.
She said U.S. beef remains "absolutely safe to eat," adding that she plans to serve it at her Christmas dinner Thursday.