Wyoming state officials feared they had a direct link from a bull in Wyoming to a case of mad cow disease in Canada earlier this week, but it turned out to be a false alarm.

Canadian and United States officials were tracking down 24 animals that may have been linked to the single mad cow in Alberta and found them in Montana. Briefly, they thought one of them had been sent to Wyoming.

Wyoming State Veterinarian Jim Logan got a phone call from his Montana counterpart on Wednesday night.

"It appeared then that we had one of those bulls in Wyoming," he said. The five-year-old bull had been sold at Miles City Livestock in August of 2000, Logan said. The buyer was an agent to sometimes purchased cattle for the Torrington Livestock operation, he said.

By late Thursday, Logan and his staff had established that the bull did not go to Torrington, but was shipped to St. Paul, Minn. Logan said it was likely that the bull was headed for slaughter, but that Minnesota officials will have to trace it down.

Logan said he and his staff continue to use their extensive records to back trace any connections with the Canadian herds of concern.

"We haven't found any," Logan said.

Ron DeHaven, a deputy administrator for the Agriculture Department, said Thursday that officials are trying to determine which five of the 24 bulls kept on the Montana farm were connected to the case in Canada.

It is proving to be a difficult task, he said, because 23 of them were shipped to plants in six states sometime from 1999 to 2002. Investigators are still gathering information on one bull.

Two weeks ago, Canadian officials found that a cow in Alberta was infected with mad cow disease, or bovine spongiform encephalopathy, a brain-wasting illness. The United States immediately banned all imports of Canadian beef and cattle as a precaution.

However, the investigation expanded this week after officials found five bulls linked to the sick cow were sent to Montana in 1997. It's the first time the investigation has moved into the United States from Canada, but officials have said chances are slim that the bulls were infected.

Still, they want to be sure.

Through interviews and documents, investigators found that the bulls were sent to Minnesota, Montana, Nebraska, South Dakota, Texas and Wyoming.

"Even if these animals did go into the animal feed or the human feed chain, we think it's highly unlikely that any of these animals would have been infected," DeHaven said.

U.S. officials determined that:

-Five bulls were slaughtered in Minnesota, possibly for human consumption or animal feed.

-One was slaughtered in Montana for private consumption.

-Three were sent to Nebraska for slaughter or for animal feed.

-A dozen were killed for human consumption or animal feed in South Dakota.

-Two were slaughtered in Texas, perhaps for human food or animal feed.

Humans cannot get sick from eating meat from an infected cow unless it contains tissue from the animal's brain or spinal cord. The human form of the disease is known as variant Creutzfeldt-Jakob Disease, which can cause paralysis and death.

Nearly 130 people in Britain died of it after a large mad cow outbreak in the 1980s.

Mad cow disease can spread among cattle if they eat feed containing tissue from the brain and spinal cord of an infected animal. The United States and Canada have had a ban on such feed since 1997.

Cattle still can be rendered for animal feed for other species like dogs that aren't known to get sick from infected tissue.