Phippsburg Years ago, former biology teacher Dan Craig was thumbing through a book he used for one of his classes and came across a word he didn't know prion.
"I thought I'd better find out about it," he said.
Craig, today a rancher in Phippsburg and longtime president of the Routt County Farm Bureau, said that was his first step toward learning about chronic wasting disease, which recently was discovered in four deer in Routt County.
Craig began corresponding with California neurologist Stanley Prusiner, who was leading research into prions. He explained that prion was short for "pathogen proteinaceous infectious particles," basically proteins without DNA that cause certain neurological diseases. Prusiner's work wasn't accepted at first.
"At the time, everyone was laughing at him," Craig said. "Then he won the Nobel Prize."
Indeed, Prusiner was awarded the prize in 1997 for his discovery of prions, which are the contagions that cause mad cow disease and chronic wasting disease.
It was the fear of prions being spread through the deer and elk herd in Northwest Colorado that prompted the Colorado Division of Wildlife to recently kill 329 deer around the Motherwell Ranch southwest of Hayden and conclude that more deer, and now elk, will be killed to help stop the first outbreak of chronic wasting disease west of the Continental Divide.
Four deer have been identified with the disease near Hayden, adding to a list of small outbreaks popping up around Colorado and most of the western and central western states and also in places such as Saskatchewan in Canada and even in South Korea.
"This is not a new disease," Craig explained. "It's been around in some form or another for a while."
The first record of chronic wasting disease came in the late 1960s at a DOW research facility in Fort Collins. Captive deer began showing what today are definite signs of the disease: losing weight, insatiable thirst, urinating often, ears drooping and saliva dripping from the mouth, according a report from the Wyoming Game and Fish Department.
The disease then appeared in a research facility in Wyoming, presumably because some of the deer there came from the Colorado pens.
Between 1974 and 1979, 57 out of 66 deer held in captivity at the two facilities died from the newly named chronic wasting disease.
The first diagnosed cases in the wild came in 1981. It was first found in a young elk from Rocky Mountain National Park and later that year in a deer found north of Fort Collins.
Terry Spraker, a veterinarian pathologist in the diagnostics lab at Colorado State University, diagnosed both animals in 1981 and remains working on the disease today.
"It was a surprise that we found it in the wild," he said.
There are two theories on how chronic wasting disease started, Spraker explained.
One is that it spontaneously occurred, either in one certain population of deer or in numerous populations. The other theory is that captive deer came in close contact with domestic sheep that were infected with scrapie, a similar disease caused by prions.
Either way, when it showed up in the wild in 1981, it proved the disease was spreading.
Since then, Spraker has diagnosed hundreds of cases, and though nothing has been proven, he said observations show the disease is being passed by feces and saliva.
"This way it contaminates the ground, then it contaminates the food," he said.
Prions accumulate in the lymphnoid tissues and intestinal track and saliva glands of an infected deer (but just in the intestinal track of an elk). It is being widely considered that when elk or deer ingest the droppings, urine or the saliva from an infected animal, it ingests the prions and is infected.
This "ground contamination," can explain why so many captive animals died from chronic wasting disease when it was first discovered in the pens.
However, during that time, the pens were disinfected and left empty for six months to a year, but the disease still found its way back to the research labs. Spraker theorized the pens could have been clean after lying empty for so long and that the deer, taken from the wild, could already have been carrying the disease. Putting them in a confined area just aided the spread.
"I think any time you concentrate animals, you have the potential of spreading the disease more," Spraker said.
It also explains why some people are asking for game ranches, which pen animals into an enclosed area for hunting, to be more scrutinized when controlling chronic wasting disease.
"Until we start to discuss the possibility of shutting down game ranches, all the culling likely won't address the problem," said David Crawford, executive director of the Rocky Mountain Animal Defense, which is a group that is for the protection of animals.
Meanwhile, game ranchers and the organizations that back them say the penned animals were infection-free until the DOW failed to contain the disease on the outside of their fences.
Though the finding of chronic wasting disease on the west side of the Continental Divide is further sparking debate, perhaps the more significant discovery was in Wisconsin in February, which is what has Spraker concerned.
"As the disease moves east, you are going to see it more in the white-tails," he said.
White-tailed deer congregate more than mule deer and black-tails in the West. That could increase the chances of the disease spreading. Also, white-tailed herds are larger than mule deer herds, and wildlife managers in eastern states feed the animals more, further encouraging the herds to congregate.
So far, the DOW has used the culling to contain and test for the disease and is being upfront about the unknowns out there.
Craig said he is impressed with the stance being taken.
"I was very pleased about the way government agencies have dealt with this stuff," he said. "I don't think anything is being hidden."