Can Mad Cow Disease Reach Our Shores?: Part 2

The Food and Drug Administration (FDA) has confirmed that a Texas cattle herd was mistakenly given feed with a small amount of prohibited animal by-products that could conceivably carry mad cow disease.

The cattle will be barred from the human food supply, even though the risk of a mad cow outbreak is small and there's never been a case of the illness in the United States. But, as CBS News correspondent Vince Gonzales reports in part 2 of a three-part series, in the American West a mad-cow-like disease is now destroying animal brains and killing deer and elk.

Wyoming State veterinarian Tom Thorn says that mad cow disease has drawn a lot of attention to this other disease. "What we watch for in an affected deer is kind of a hollow look in their eyes. They drink a lot. They don't eat very much."

The animals waste away, which is why the always-fatal disorder is called chronic wasting disease, or CWD. The animals also behave strangely, losing their fear of humans as CWD destroys their brains. But an infected animal can look totally normal in the early stages of the disease.

CWD was first noticed at a Colorado research facility in 1967. Mike Miller of the Colorado Division of Wildlife told a government committee recently, "What we are seeing is an epidemic occurring in slow motion."

Scientists say the epidemic is slowly spreading among wild deer and elk in Nebraska, Wyoming, and Colorado, where at least 15% of some wild herds are infected. It's also been found on game farms in five states and one Canadian province.

In a video produced by wildlife officials in Colorado and Wyoming, hunters are told that "relatively little is known about chronic wasting disease." And they're warned to wear gloves and avoid touching or eating parts of the animal where the disease is concentrated: the brain, spinal column, lymph nodes, tonsil, spleen, and bone marrow.

When it was detected in Montana, drastic measures were taken. Scores of game farm elk were incinerated. Dozens of deer on nearby land were hunted by helicopter, killed, and tested to keep this highly contagious disease from spreading.

Hunters are being used to control the spread of CWD in the wild. In Colorado the hunting season was extended this year in some disease areas as a way to try and lower the diseased-animal population. Hunters in some sections of the state must drop off deer heads for CWD testing. Testing is voluntary in Wyoming and Nebraska.

Wildlife officials insist that as long as hunters are informed about CWD and take precautions, the disease is not a human health threat.

Thorn argues, "You cannot say with 100% certainty that it won't transmit to people, but there is no evidence that it will transmit to people."

When asked if he was concerned about CWD, Thorn said, "No. I've lived here quite a long time. I've hunted here. I just have not seen any credible evidence that it's going to kill me or anybody else."

Despite all the official asurances, some hunters and their families fear eating diseased meat could infect them with the same fatal brain disorder that's killing deer and elk.

"I've hunted in this area and I've been eating deer all my life," said Chris Melani, who shot a deer in Colorado and, as required, turned in the head for testing. He said he was told he would be notified within 3 weeks if his deer had the disease.

"I didn't get a notice so I figured everything was okay with the deer. We started eating it," he said.

Melani and his then-pregnant wife Deb also sent some of the meat to a sausage maker, who sold it to other customers. The Melani's gave their sausage to friends and family as Christmas presents. Then, almost 2 months after his hunt, Melani received a letter.

"I was shocked when I started reading it, recalls Melani.

His deer had CWD.

"What's done is done. You just go on with your life and hope it's healthy," Melani said.

But Jay Whitlock didn't get to go on withis life.

Jay, an Oklahoma hunter, was 27 when he developed a brain disorder similar to CWD and mad cow disease.

Julie Whitlock said, "Jay's case is not genetic. They have ruled that out. And they said we'll probably never know actually how Jay did get it."

Jay Whitlock died a year after CBS News spoke with him.

His case, and two others, were discussed at a recent government meeting on chronic wasting disease.

Although the victims ate deer meat, scientists could not link their deaths to CWD.

Ermias Belay, MD, a medical epidemiologist with the federal Centers for Disease Control and Prevention, told the FDA panel, "However, our conclusions are limited to three patients and continued surveillance remains very critical to continue to monitor the possible transmission of chronic wasting disease to humans."

There is evidence, at least in the lab, that in rare cases this disease can alter human brain tissue almost as effectively as mad cow disease.

The government says so far there is no proof any humans have been infected by deer and elk. But after the deaths in Europe, no one is willing to say it can't happen here.

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