A second case of BSE or "mad cow disease" has been confirmed in the US, officials say.
The first US case of BSE was recorded in Washington State
It was verified by tests conducted by a laboratory in Britain after a suspect test was announced earlier this month by the US Department of Agriculture.
The department said there was no public health risk as no meat from the animal - which died last November - had entered the food chain.
The first US case was found in the state of Washington in 2003.
That discovery - in a cow imported from Canada - halted billions of dollars worth of American beef exports and raised questions about the safety of the US food supply.
The Department of Agriculture says it is investigating where the latest infected animal originally came from.
Speaking on Friday at a news conference after the second case had been confirmed, Agriculture Secretary Mike Johanns said the presence of the disease was extremely low in the US:
"This animal was blocked from entering the food supply because of the firewalls we have in place. Americans have every reason to continue to be confident in the safety of our beef."
He added: "I enjoyed beef this noon for lunch."
A form of the disease in people, called variant Creutzfeldt-Jakob disease, has been linked to eating contaminated meat.
The disease has killed about 150 people worldwide, mostly in Britain, the epicentre of an outbreak in the 1990s.