The USDA has confirmed the nation’s first case since 2006 of bovine spongiform encephalopathy (BSE) in a dairy cow from central California.
Samples from the animal in question were tested at USDA’s National Veterinary Services Laboratories in Ames, Iowa. Confirmatory results using immunohistochemistry and western blot tests indicated the animal was positive for atypical BSE, a very rare form of the disease not generally associated with an animal consuming infected feed.
According to USDA Chief Veterinary Officer John Clifford, the carcass of the animal is being held under State authority at a rendering facility in California and will be destroyed. The animal was never presented for slaughter for human consumption, so at no time presented a risk to the food supply or human health.
“Evidence shows that our systems and safeguards to prevent BSE are working, as are similar actions taken by countries around the world,” said Clifford. “In 2011, there were only 29 worldwide cases of BSE, a dramatic decline and 99% reduction since the peak in 1992 of 37,311 cases. This is directly attributable to the impact and effectiveness of feed bans as a primary control measure for the disease.”
The USDA is conducting an epidemiological investigation in conjunction with California animal and public health officials and the FDA. The agency will also share laboratory results with international partners in Canada and England which have extensive experience diagnosing atypical BSE and will review the test results. The USDA stated that it has no reason to believe that any other U.S. animals are currently affected and that this detection should not affect U.S. trade.
BSE is a progressive neurological disease among cattle that is always fatal. It belongs to a family of diseases known as transmissible spongiform encephalopathies. Affected animals may display nervousness or aggression, abnormal posture, difficulty in coordination and rising, decreased milk production, or loss of body weight despite continued appetite.
Consumption of meat contaminated with BSE can cause the human disease known as Variant Creutzfeldt-Jakob Disease (vCJD) in which the brain tissue develops holes and takes on a sponge-like texture due to an infectious protein called a prion. The rare disease is degenerative and invariably fatal.