Mad cow case in California found by USDA testing

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.