The U.S. Department of Agriculture confirmed the United States’ fourth case of bovine spongiform encephalopathy, also known as Mad Cow disease, in a dairy cow from central California, the agency reported today.
The cow was not presented for slaughter for human consumption and did not pose a risk to the food supply or human health, according to the USDA. As of this morning, the cow was being held at a rendering facility in California and will later be destroyed.
The positive test will not affect the United States’ bovine spongiform encephalopathy status as determined by the World Organization for Animal Health (OIE), nor will the detection affect U.S. trade, the USDA said.
The USDA’s National Veterinary Services Laboratories in Ames, Iowa, confirmed the animal was positive for bovine spongiform encephalopathy using immunohistochemistry and western blot tests. The tests revealed an atypical form of BSE, not generally associated with an animal consuming infected feed, according to the USDA.
The agency will share its laboratory results with animal health reference laboratories in Canada and England, which have official OIE reference labs and more experience diagnosing atypical BSE. The USDA will also conduct an epidemiological investigation in conjunction with California animal and public health officials and the U.S. Food and Drug Administration.
“This finding is not cause for alarm because the tissues of any infected cows that pose a food safety risk, i.e., specified risk materials or SRMs, have been kept out of the human food supply since early 2004,” said Ron DeHaven, CEO of the American Veterinary Medical Association. “What this finding does confirm is that the safeguards put in place by the USDA several years ago are working as they are intended.”
Those safeguards include surveillance, a mammalian feed ban and removal of SRMs and nonambulatory cattle from the food chain and surveillance. The measures implemented by the U.S. and abroad have likely played a role in the decline in reported cases of BSE from a peak of 37,311 in 1992 to just 29 last year, according to the USDA.