The USDA announced today that a single cow infected with mad cow disease (bovine spongiform encephalopathy) has been found in central California. The animal was a dairy cow and did not enter the food supply. This is the the fourth case of mad cow ever found in the US, and the first since 2006. The animal died from an atypical, rare form of the disease that is “not likely attributable to infected feed,” according to a USDA spokesperson.
BSE usually occurs when cattle eat meat or other parts of other, infected cows; causes for the “atypical” version of the disease are unknown. BSE can be transmitted to humans who eat meat byproducts, usually from the spinal cord or brain, of infected cattle. The human form, known as variant Creutzfeldt-Jakob disease, has a long incubation period but is incurable and leads to dementia and death. The number of cases of BSE reported globally has waned dramatically: 29 cases reported in cows last year, compared with 1,000 new cases a week at the disease’s height in 1993 in the UK.
The USDA was quick to assure the public that there is no danger to the US food supply, and put out this video press release featuring Chief Veterinary officer Dr. John Clifford:
The AMI’s website states that the US “processed” 33.3 million cattle in 2009. Discovery of this BSE case, even though it was a dairy cow, will likely impact the US beef industry, which was slow to recover export contracts after discovery of the first US case in 2003. The US exported just over one million metric tons of beef in 2010; top markets are Mexico, Canada and Japan.
image by matthew_hull via MorgueFile