According to Bloomberg, The first U.S. case of mad cow disease in six years has been found in a dairy cow in central California, John Clifford, the U.S. Department of Agriculture’s chief veterinarian, told reporters today in a briefing in Washington. The cow was found at a rendering facility as part of routine testing for the disease, known as bovine spongiform encephalopathy (BSE), Clifford said. Its meat didn’t enter the food chain and the carcass will be destroyed, he said.
This is the fourth confirmed case of BSE found in the United States.
Washington State: On December 23, 2003, the U.S. Department of Agriculture (USDA) announced a presumptive positive case of BSE in a Holstein cow slaughtered in the State of Washington. The infected cow entered the United States on September 4, 2001, as part of a shipment of 81 animals from the source herd in Canada. Of these 81 animals, 25 were considered to be higher risk as defined by the Office International des Epizooties (OIE): animals born on a known source premises within 12 months of an affected animal, either before or after.
Texas: In June 2005, an inconclusive bovine spongiform encephalopathy (BSE) sample from November 2004, that had originally been classified as negative on the immunohistochemistry test, was confirmed positive on SAF immunoblot (Western blot). The U.S. Department of Agriculture (USDA) identified the herd of origin for the index cow in Texas; that identification was confirmed by DNA analysis.
Alabama: On February 27, 2006, an Alabama cattle producer contacted his herd veterinarian and reported that he owned a cow that was down and unable to rise. He had last seen the cow approximately three days prior and had not noted any abnormalities at that time. Upon examination the veterinarian found the cow in right lateral recumbency with her feet pointing uphill. The cow was unable to rise after being rolled onto her sternum. The differential diagnoses at the time of the visit included hypocalcemia (milk fever) and hypomagnesemia (grass tetany). Grass tetany is a common cause of downer cows in Alabama during this time of the year. Intravenous and oral mineral supplements were administered with minimal clinical improvement. After treatment, the cow displayed tremors of the head and neck and was still unable to rise. On the following day, February 28, the cow remained in lateral recumbency and she was euthanized and the obex removed to test for bovine spongiform encephalopathy (BSE). On March 15, NVSL completed immunohistochemical testing on the tissues, confirming the second native case of BSE in the United States.
In 2008, concerns over mad cow disease prompted the USDA to force Hallmark and Westland Meat Packing Company of Chino, California to recall 143,383,823 pounds of raw and frozen beef products – the largest meat recall in United States history. This recall lead to the Agriculture Secretary Tom Vilsack in 2009 to announce a complete ban on the slaughter of cattle that become non-ambulatory disabled (The Downer Cow Rule) after passing initial inspection by Food Safety and Inspection Service (FSIS) inspection program personnel.