John Pape from Colorado's Health Department said: "At this point, the answers to these questions are unknown. Because of the BSE experience, it is theoretically possible, and based on that there are some precautions that hunters may want to take."
In the foothills of the Rockies, Steve Wolcott sets out a final winter feed for his herd of elk.
With the arrival of spring comes a new threat - a form of mad cow disease for deer and elk.
"It may be a problem when infected carcasses are brought back across the country," he said. "I think we have to be concerned about this material being able to infect other wild deer populations in other parts of the country."
The disease is identical to BSE in the way it attacks the brains and nervous systems of the deer. It cannot be detected until shortly before death.
Threat to humans
And there is an additional cause for concern - laboratory tests have shown that humans could contract this illness in the same way as BSE, although no cases have been confirmed so far.
John Pape from Colorado's Health Department said: "At this point, the answers to these questions are unknown. Because of the BSE experience, it is theoretically possible, and based on that there are some precautions that hunters may want to take."
A farm in the mountains of Nevada may hold a key to the puzzle of Mad Deer disease.
The farm's owner, a cowboy called Jim Koepke, died suddenly from Creutzfeldt Jakob Disease (CJD), an illness very similar to both BSE and the Mad Deer variant.
Brenda, Jim's widow, admits that he loved to hunt. It is possible that he may have died from eating infected deer meat.
"I couldn't comprehend that a cowboy in the middle of farming Nevada could get such a horrendous disease," she said. "So I dragged the poor man to many other doctors looking for something that made an ounce of sense."
Just coincidence?
Jim Koepke was the third deer hunter to die in the last two years from CJD. So far the evidence suggests that it is just coincidence.
But in Colorado, where as many as one in five deer and elk now has the disease, the authorities are urging caution.
"We encourage hunters to wear gloves when they field-dress carcasses, and at the very least to avoid consuming some of the tissues that we know harbour the chronic wasting disease - things like brain and spinal cord," said Michael Miller, a Colorado vet.
What is eerie is how similar the comments of American experts are to those of British government officials during the early years of the Mad Cow crisis.
There may be no evidence yet of a threat to humans, but no one is even sure how this disease is transmitted from deer to deer, and the British experience should show us that nothing can be taken for granted.