The U.S. Department of Agriculture says it has confirmed a case of Mad Cow disease in a cow in central California. It is the fourth case found in the country in recent years.
The animal was a dairy cow and "at no time presented a risk to the food supply or human health," U.S.D.A. Chief Veterinary Officer John Clifford said in a statement.
The cow, which will be destroyed, tested positive for "atypical" bovine spongiform encephalopathy, which is "a very rare form of the disease not generally associated with an animal consuming infected feed."
Clifford said the cow was found at a redering plant through U.S.D.A. sample testing. The cow was never meant for human consumption and milk does not transmit mad cow.
In the statement, Clifford said the finding should not affect U.S. trade.
Update at 3:56 p.m. ET. 'No Cause For Alarm':
"There is really no cause for alarm here with regard to this animal," Clifford told reporters at a press conference, according to the AP. The news service adds:
"There have been three confirmed cases of BSE in the United states, in a Canadian-born cow in 2003 in Washington state, in 2005 in Texas and in 2006 in Alabama.
"The Agriculture Department is sharing its lab results with international animal health officials in Canada and England, Clifford said."
Update at 6:17 p.m. ET. A Bit More On What 'Atypical' Means:
The AP spoke to to Bruce Akey, director of the New York State Veterinary Diagnostic Laboratory at Cornell University. Basically, he explained, this cow's disease is the result of a random genetic mutation "that can happen every once in a great while in an animal."
Mike Doyle, director of the University of Georgia's Center for Food Safety, also told the AP that in this case the testing system worked "because it caught what is a really rare event."
Also, the AP adds in its latest write-through, after an outbreak in the early 90s in England, the U.S. banned the use of "recycled meat and bone meal" in cattle feed and that has stopped the spread of the disease in the country.