The apparently isolated, random case is only the fourth-ever discovery of the disease in the U.S.
The California dairy cow that tested positive for bovine spongiform encephalopathy (BSE) in April never presented a risk to the U.S. food supply or human health, and the U.S. system of interlocking safeguards against BSE remains effective, USDA said Aug. 3 in its final report on the case.
The investigation began after the nearly 11-year-old Holstein was sampled for the disease at a rendering facility in central California. The animal was never presented for slaughter for human consumption, USDA said.
The animal was humanely euthanized after it developed lameness and became recumbent, and was sampled by a renderer contracted to collect samples as part of USDA’s ongoing BSE surveillance.
Results from immunohistochemistry and Western blot tests at USDA’s National Veterinary Services Laboratories confirmed the animal positive for atypical BSE. Samples were also sent to the World Organization for Animal Health reference laboratories in Canada and England. The laboratories confirmed that the index cow was positive for atypical (L-type) BSE.
It was the fourth-ever BSE discovery in the U.S.
In the investigation that followed, two offspring of the index animal were designated as at-risk cattle. One was traced out-of-State and depopulated with “not detected” BSE test results. The other offspring was stillborn. The carcass of the index animal and some 90 other carcasses being held at the renderer’s transfer station were disposed of in a landfill in accordance with all federal, state and local regulations. The carcass of the index animal did not enter the human or animal food chain, USDA stressed.
In conjunction with USDA’s investigation, the U.S. Department of Health and Human Services’ Food and Drug Administration (FDA) and the California Department of Food and Agriculture (CDFA) conducted an extensive feed investigation. Twelve feed suppliers were identified to the index premises; one of which was no longer in business. The remaining 11 were found to be in compliance with FDA and CDFA regulations and requirements.
Click here to read FDA’s report on the feed investigation.