HANFORD, Calif. — The discovery of mad cow disease in a dead dairy cow came soon after it arrived at a nondescript building in the heart of California's dairy country.
The finding, announced Tuesday, is the first new case of the disease in the U.S. since 2006 and the fourth ever discovered in the country. The test was performed when the animal was brought to the building, a transfer facility for a processing plant near Hanford.
The cow had died at one of the region's hundreds of dairies. A plant official said the cow hadn't exhibited outward symptoms of the disease: unsteadiness, incoordination, a drastic change in behavior or low milk production. When the animal arrived April 18 at the facility with a truckload of other dead cows, it met government testing criteria: older than 30 months and a fresh corpse.
“We randomly pick a number of samples throughout the year, and this just happened to be one that we randomly sampled,” said Dennis Luckey, Baker Commodities executive vice president. “It showed no signs” of disease.
The samples went to the food safety lab at the University of California, Davis. By April 19, markers indicated the cow could have bovine spongiform encephalopathy (BSE), a disease that is fatal to cows and can cause a deadly human brain disease in people who eat tainted meat. It was sent to a Department of Agriculture lab in Iowa for further testing.
Tuesday, federal agriculture officials announced the findings: the animal had atypical BSE. That means it didn't get the disease from eating infected cattle feed, said John Clifford, the Agriculture Department's chief veterinary officer.
It was “just a random mutation that can happen every once in a great while in an animal,” said Bruce Akey, director of the New York State Veterinary Diagnostic Laboratory at Cornell University. “Random mutations go on in nature all the time.”
In humans, experts say it can occur in one in 1 million people, causing spongelike holes in the brain. But they say not enough is known about how and how often the disease strikes cattle.
The California Department of Public Health and the state Department of Food and Agriculture quickly worked to assure consumers that the food supply is safe. The cow hadn't been destined for human consumption and people cannot become ill from drinking milk, experts say. The building where the cow was selected to be tested sends animals to rendering plants, which process animal parts for products not going into the human food chain.
Farm's name not given
Among the unknowns about the case is whether the animal died of the disease and whether other cattle in its herd are similarly infected. The name of the dairy where the cow died hasn't been released.
“It's appropriate to be cautious, it's appropriate to pay attention and it's appropriate to ask questions, but now let's watch and see what the researchers find out in the next couple of days,” said James Culler, director of the UC Davis dairy food safety laboratory and an authority on BSE.