June 1, 2002 Rocky Mountain News (Denver, CO) by Gary Gerhardt and Todd HartmanBeneath the majestic peaks of Rocky Mountain National Park, along the rolling shortgrass and sagebrush prairie of northeastern Colorado, and now, alarmingly, through the valley-bottom ranches of the Western Slope, a killer is stalking the state's wildlife.
Threatening the very foundation of Colorado's reputation as an outdoor wonderland, the mysterious disease is reducing the state's deer and elk to staggering, starving victims of an infectious agent that rots the brain, kills the host and survives to strike again.
The sickness called chronic wasting disease has now crossed the Continental Divide, a once unimaginable leap frightening to sportsmen, biologists and politicians alike. At stake: the Western Slope's storybook wildlife herds and the small-town livelihoods sustained by free-spending hunters.
"This is the worst-case scenario," said Chuck Reichert, a district wildlife manager in northwestern Colorado who lately has been forced to gun down the very deer herds he is paid to help manage - all in a desperate effort to slow the spread of CWD. "Wildlife and hunting is the root of our economy - it's what rural people do to make a living." Colorado is, in fact, the epicenter of the emerging disease, one among a cluster of closely related maladies known as transmissible spongiform encephalopathies, or TSEs. Mad cow disease is a TSE that has killed humans in Britain and Europe. The common denominator is a rogue protein called a prion that attacks healthy brain tissue, riddling it with holes.
Once believed confined to a sparsely populated, 14,873-square-mile region of northeastern Colorado and southern Wyoming, chronic wasting disease's leap west of the Rockies - and its equally stunning jump east, across the Mississippi River into Wisconsin - is sounding national alarms.
Scientists, including a Nobel prize winner, the meat industry and public health experts are scrambling to learn more about the baffling disease. CWD has not been found to infect cattle or people, but the deadly experience with mad cow disease is driving urgent research on the question.
"We don't know how it would jump," said Gregory Raymond, a federal scientist with Rocky Mountain Laboratory of Persistent Viral Diseases in Hamilton, Mont. "However, we do know it's possible for diseases of one species to cross the barrier to other species."
Regarded for more than two decades as nothing more than an obscure, slow-moving animal sickness - indeed, it has been described as an epidemic in slow motion - troubling new developments are triggering fresh concern over chronic wasting disease:
Discovery in recent months of what appears to be a rampant expansion of the disease has pushed CWD from its long-festering confinement in the endemic area between Fort Collins and Casper to wildlands of three additional states, and western Colorado, where biologists hoped 14,000-foot mountain peaks might block its path.
Chronic wasting disease is spread in the environment from animal to animal, perhaps via contact with feces, urine and saliva. That's different from the cattle version of TSE, which was passed along when cows were fed infected meal ground from diseased animals.
The infectious prion believed to cause CWD apparently remains viable in the natural environment for years, destroyed by incineration at temperatures exceeding 1,110 degrees or by a bleach bath.
There's no known case of CWD infecting a person, but recent research raises new concerns. One set of laboratory experiments demonstrated the disease could be undetectable in one group of exposed mice, then, when passed to another group, strike with uniform deadliness. In another study, infectious agents like those that cause CWD were found in muscle tissue of genetically manipulated mice. This finding has brought calls for further study of the possible presence of disease agents in the muscle - the meat - of deer, elk, cattle and sheep.
The disease has prompted a publicly backed wildlife slaughter of historic scale. State biologists in Colorado and three other states have fanned out to kill hundreds of wild deer to both curb the spread, and test for the presence, of CWD. Nebraska and Colorado officials are loosening hunting limits dramatically, in hopes of trimming deer populations by the thousands to deprive CWD of new hosts.
The disease appears especially virulent among white-tailed deer, a highly social species that thrives in vast numbers east of Colorado. In one 800-acre pen in Nebraska, half the whitetails contracted CWD, a staggering rate of great concern to biologists. These numbers particularly alarm officials in Wisconsin, where a massive herd of 1.5 million whitetails crowds the state's woodlands. The state plans to eradicate about 115,000 deer in an attempt to halt spread of the disease there.
CWD has ravaged the domestic elk industry in Colorado and beyond. Agricultural agencies in six states have slaughtered more than 3,800 captive elk exposed to wasting disease, costing taxpayers nearly $15 million, most of it to compensate elk ranchers. In Canada, CWD has struck in two provinces, leading to the slaughter and incineration of nearly 8,000 domestic elk. There is continuing debate about the role of ranched elk in the disease's spread.
Wildlife agencies and commerce officials say chronic wasting disease could cost states billions of dollars if hunters, scared off by infected herds, stay away. Small-town hotels, gas stations, restaurants and sporting goods shops will suffer. Meanwhile, many wildlife agencies, including Colorado's, rely almost entirely on hunting license fees and fear a revenue loss that could leave them no money to operate.
In just months, CWD has erupted into a political crisis. In Colorado, with state wildlife and agricultural agencies feuding over the role of wildlife and captive elk in spreading the disease, officials haven't agreed on regulations designed to manage CWD. In March, Colorado Gov. Bill Owens called a dramatic Good Friday press conference to declare the disease a threat to the state's economy and environment. Behind the scenes, he ordered bickering agencies to call a truce and work on solving the problem.
At the root of the dread over CWD is the belief that it may be the most virulent and easily transmitted - among the species it infects - of all the TSE strains, which also include scrapie in sheep and the rare but naturally occurring Creutzfeldt-Jakob disease in humans. When mad cow disease crossed the species barrier to kill humans, it became known as new variant Creutzfeldt-Jakob disease, or vCJD.
In all forms, the disease attacks the brain and central nervous system, destroying healthy tissue. The victim loses basic physical and mental abilities as the disease progresses.
To date, there is no cure for the fatal illnesses, and there is no way to test for them in their early stages.
A MYSTERY WITH AN UNKNOWN BEGINNING
If the story of chronic wasting disease were written as a mystery novel, it would be lacking the first chapter. There are strong, plausible theories about its origins in Colorado, but as with so much else about the disease, there is no definitive proof.
In the 1960s, a number of research projects involving mule deer were ongoing at Colorado State University's foothills campus west of Fort Collins.
"I was told that as early as 1967 they were seeing deer go down in the pens at CSU," said Mike Miller, veterinarian for the state Division of Wildlife. "They just lost weight and died and it was believed they were missing something in their diets."
The deer were described as wasting away, thus the origin of the chronic wasting name a full decade before the disease was discovered to be a TSE.
About that time, a Colorado State University graduate student named Gene Schoonveld had started work on a nutritional study of mule deer for his master's thesis.
Schoonveld's three-year project was to determine why mule deer didn't digest alfalfa and hay provided during harsh winters.
In addition to his test animals, the wildlife division supplied about four dozen deer from the wild that were held in a separate 40-by-45-foot enclosure.
Because he wanted to do a comparative anatomy study, CSU gave him domestic sheep that also were in the enclosure with the deer.
"They were in close proximity of the sheep for long periods of times and it was among those animals that the symptoms of CWD first showed up," said Schoonveld, now a Division of Wildlife biologist.
"Soon after they were together, adult deer started showing signs of CWD - abnormal behavior, excessive drinking and urinating, emaciation, excessive salivation, stumbling, trembling and depression before they died."
Over the term of his study, he estimated one deer per month died of the strange malady.
The veterinary school necropsied the deer and reported the results as "enteritis," an inflammation or infection of the intestinal tract. The brain was not suspected.
A number of people now recall that the sheep in the corrals at CSU had scrapie, but no documentation has been found to prove it.
"There were a number of deer projects going on at the time and deer were coming in from the wild that may have been infected, and we were trading deer with Sybille (the Wyoming Game and Fish Department's Sybille Research Unit, near Wheatland, Wyo.), and so it's impossible to say for sure how it got started," Schoonveld said.
"But my guess as a biologist is those sheep had scrapie, and in close confinement - something that they wouldn't do out in the wild - it jumped to deer and infected them.
"The deer then spread it among themselves."
YOUNG RESEARCHER FINDS THE 'BULLET'
Late one night in November 1977, a decade after Schoonveld's research, an eager young graduate student named Beth Williams peered into a microscope at tissue of a deer's brain in a lab in the pathology building at Colorado State University.
Her curiosity fueled by a great interest in wildlife diseases, Williams was poring over slides containing brain tissue from deer that had died of chronic wasting.
"No one had an idea at the time what was causing deer to waste away in our pens, but as I looked at the slides, I noticed lesions that were absolutely striking," Williams said in a recent interview. "They looked exactly like scrapie, the holes that form in sheep brains."
Scrapie is a disease dating back more than two centuries in Europe. It first was diagnosed in the U.S. in 1947 in a Michigan flock, and since then has been found in more than 1,000 flocks in this country. Infected sheep scrape themselves raw against fence posts or whatever is nearby, giving the disease its peculiar name. But scrapie had never been known to jump to other species.
Overcome by the excitement of her find, Williams raced to find her mentor, Dr. Stuart Young, a neuropathologist. But he had left for the evening.
She put a slide with a section of tissue on Young's office door with an explanation of what she believed she had found. She called Tom Thorne, already a respected Wyoming wildlife veterinarian and her future husband.
"I don't remember that CWD was the only reason I called him," she said. "But I told Tom I thought maybe we had a lead on what was going on with the deer and he agreed."
The following day, Young studied the slide. He agreed that it looked like a spongiform encephalopathy, and sent a section to Dr. Bill Hadlow at the Rocky Mountain Laboratories in Montana. Hadlow was considered one of the leading veterinary neuropathologists and an expert on scrapie.
Hadlow confirmed the similarities.
Williams, currently a professor of veterinary sciences at the University of Wyoming in Laramie and a leader in the field of CWD research, had discovered the "bullet" in the mystery that is CWD. The disease attacked the brain.
Did scrapie jump the species barrier to become CWD in deer?
"While it's reasonable to assume such a jump occurred from sheep to deer, there is absolutely nothing to prove it," Williams said. "It's equally as plausible that CWD is a naturally occurring disease as well."
Between 1974 and 1979, 66 mule deer were held captive in the Colorado and Wyoming research corrals. Of that number, 57 contracted CWD and died. By the time Williams made her discovery in 1977, any number of research animals had been exposed to the disease in the pens and then released back into the wild.
Veterinarian Mike Miller said his records indicate the last deer released from the contaminated pens was a buck in April 1980. It had been a free-ranging animal that was captured, held 18 months, then released.
Miller said throughout the 1970s before CWD was discovered, a number of deer were captured in the wild, bred, their fawns taken from them, and then turned loose north of Fort Collins.
"No one at the time understood what was killing the deer in the pens was a contagious disease," Miller said.
It was only a matter of time before the strange illness would be seen outside the pens. But no one was prepared for just how it happened.
In 1981, a magnificent bull elk, one of Rocky Mountain National Park's living icons, was found dead of chronic wasting disease in Moraine Park.
It was the first known CWD death outside of the pens at CSU and Sybille.
CWD IN THE WILD
Exactly how CWD became a killer in the wild remains part of the mystery.
It may be that CWD is a naturally occurring malady and animals already were infected in the wild before being held at CSU. While there, they could have spread the infection.
It may have been that sheep with scrapie were nose-to-nose with deer over prolonged periods and somehow the disease crashed the species barrier and infected one deer, which, in turn, quickly infected its pen-mates. Animals that were captured for research or breeding became infected and were released before anyone had any inkling about the disease.
Or it could have been that animals huffing and puffing around the outer perimeter of the woven-wire fences at CSU during rutting season contracted the disease from infected animals within.
Colorado Division of Wildlife veterinarian Miller, Wyoming Game and Fish veterinarian Thorne and others believe in the "lateral transfer" of the disease, meaning it passes directly through feces, urine or saliva. It also seems likely that it contaminates the ground and plants, and then remains contractible for many years.
The CWD prion has proved very tough to kill.
Thorne said that after CWD was discovered at Sybille, all the deer and elk were killed and the pens went unused for up to a year. Within five years after animals were returned, they came down with CWD.
At Fort Collins, an effort was made to sanitize the soil after the deer and elk in the CWD pens were killed. The ground was plowed, then sprayed with bleach strong enough to kill the rogue prions.
A year later, 12 elk calves were placed inside the sanitized holding areas, and within five years, two died of CWD.
Regardless of how CWD came to be in the wild, in retrospect, it is evident that by the mid-'80s the disease had established itself in the high plains environment between Fort Collins and Casper, bounded by the North and South Platte rivers, and extending to the Nebraska state line.
"It was formally declared an endemic area in 1995 when we did some surveys of the animals and realized we had way underestimated the extent and severity of the disease," Miller said.
In the endemic area, the state required all hunters to turn in heads in the 1996 through 1998 hunting seasons.
Even within this region, rates of infection vary.
Elk have remained at about a 1 percent infection rate throughout northeastern Colorado.
For deer, in some areas the average is as high as 15 percent.
"When we say 15 percent, it is the total over the entire time of the study, not the number of sick animals at any given time," Miller said.
While the figures may seem low, when considering 60,000 mule deer and 15,000 elk in the endemic zone, they could eventually represent hundreds, even thousands of sick and dying animals.
The endemic landscape consists of alpine and coniferous mountain shrub in the west to wetland corridors and shortgrass prairie tablelands in the east. It is a checkerboard of agricultural, wildlands and ever-increasing suburban development.
Wildlife officers complain that some residents of the region feed deer and elk bowls of dog food, which can contain meat and bone meal. Federal regulations prohibit feeding the meal to ruminants, including deer and elk.
The elk keep mostly to the western mountains and foothills, as do the mule deer, while the white-tailed deer are most prevalent in the eastern riparian corridors.
Wildlife personnel began surveying in 1983 to try to measure CWD in the region. But that was a long time before they developed any sense of urgency over what they might find.
A HEALTH HAZARD TO HUMANS?
"Honestly, CWD was little more than a curiosity in deer we were studying until mad cow came up in Britain and the concerns of the public forced us to look at CWD as a potential health hazard," said Wyoming veterinarian Thorne.
When mad cow jumped into humans, it quickly became a natural extension to ask what would happen to hunters who unknowingly ate CWD-infected deer or elk. And might CWD jump into cattle, threatening the state's ranches, great and small?
Thorne, Williams and Miller all hunt deer and elk in the endemic area and eat the venison after testing it for CWD.
But, said Williams, "I do think it is legitimate to be concerned about the potential for humans being susceptible to CWD. We don't have evidence . . . but we can't say it could never happen and we have to be prudent."
Other scientists say there is evidence - human cells have been infected in the laboratory - but no proof that CWD can afflict humans naturally.
Studies are ongoing to try to determine if deer and cattle sharing the same habitat might result in CWD jumping to cattle. None of the cattle has shown symptoms. In another experiment in which CWD prions were injected directly into the brains of 13 test cattle, three have become infected to date.
The Colorado Cattlemen's Association points to a Harvard study that discounts the risk of mad cow disease affecting U.S. cattle, and concludes the risk from CWD is minimal.
And while there's no proof that CWD can jump to cattle naturally, the cattle industry supports more research into the risks - if any - posed by CWD, according to Terry Fankhauser, executive vice president of the CCA.
"Due diligence is what's appropriate," Fankhauser said. "Wherever an unknown lies, we're concerned with that."
For now, the question of safety appears most pertinent to those who eat deer and elk.
Hunters in the Colorado segment of the endemic area last year alone killed 2,146 deer and 1,262 elk. In endemic southern Wyoming, hunters killed 5,497 deer and 798 elk.
Anyone who eats an infected animal is potentially exposed to CWD, although, again, no one has proved it can attack humans.
While researchers look for answers in fields and laboratories, CWD has been discovered elsewhere at a rapid pace.
In just the past six months, CWD cases have been reported for the first time ever outside the endemic area in Nebraska, South Dakota, Wisconsin, and, most recently, Colorado's Western Slope.
Like patches of flame exploding far in front of a wildfire, CWD has burst from its zone.
Some people suspect - although this, too, is in dispute - that CWD's spread had help from domestic elk ranches.
'A DISEASE BRIDGE TO WILDLIFE'
In the 1980s, a few cattle ranchers struggling with low beef prices turned to what they thought would be a more lucrative business - raising elk.
Unlike cattle, which produce only one commodity - meat - elk also produce velvet antlers to be ground into Asian medicines and aphrodisiacs, and "shooter bulls" for those willing to pay up to $40,000 for a "trophy" bagged inside a fence.
The latter practice is abhorrent to those who believe the "hunt" offers no chance to the hunted.
But critics of elk ranching these days do not dwell solely on the sportsmanship involved.
In fact, opponents argue that elk ranchers have played a lead role in the vast geographic jumps of chronic wasting disease in captive herds and blame them for fanning a wildlife crisis.
When ranched, elk can be unnaturally bunched together, a condition that facilitates the spread of all contagious diseases. Many scientists believe the infectious agents behind the illness are shed through saliva, so when elk are gathered to feed - a sloppy affair at best - an infected one could pass CWD to a healthy animal through contact of the mouth and nose. Urine and feces, which animals commonly contact and consume, are other suspects for the disease's spread.
The captive elk are typically kept behind large wire fences. Wild deer can breach these fences, even those reaching eight feet high. Winds can knock fences over; small floods create escape routes underneath, snow piles up, giving access over the top - all allowing wild deer or elk to enter, or captive animals to depart, passing the illness either way.
And few ranches are double-fenced. Wild and captive animals do greet one another through the wire, an exchange of spit that may also spread the disease.
Perhaps most significantly, captive elk are commonly trucked hundreds of miles, often across state lines, in trades and purchases between breeders seeking trophy bulls and anxious to maintain herd diversity.
"We're building disease bridges between livestock and wildlife," said Val Geist, a professor of zoology emeritus at the University of Calgary in Alberta and a "reformed" game ranch advocate who, persuaded by science, switched sides in 1983 and has been sounding alarms ever since.
"Many years ago I warned (game ranches) would be, potentially, a very significant route of infection," Geist said. "I have been suspicious; others have been suspicious. . . . Our predictions are coming to the fore."
In a paper written in 1992, Beth Williams also warned of the potential connection. "Should CWD become established in the captive . . . industry, transmission of this disease from game farm animals into free-ranging . . . would also be of concern."
Wyoming and Montana have banned new elk ranches, partly out of concern over diseases.
Elsewhere, federal and state agriculture officials have taken drastic measures when CWD appears on an elk ranch: the wholesale slaughter of entire herds, even though few of the animals prove to be carrying the disease.
In Colorado alone, agricultural officials have put down 3,076 captive elk. About 1,300 of those, from ranches with the misfortune of setting up inside the state's notorious endemic area, were recently exterminated - their owners stuck with a product rendered worthless by the fearsome reputation of CWD.
The question of which way the disease is communicated through the fence - from the outside in, or vice versa - remains a contentious, although possibly moot point. In the end, the public is picking up the bill to eliminate captive herds, or, in at least one case, to erect double fencing.
Elk breeders say pointing the finger at them is too simplistic. It was their own tight surveillance of their animals that led to the discovery of CWD in their herds and brought it to the attention of authorities, they say.
Further, despite the destruction of more than 3,800 captive elk exposed to CWD around the West, actual infection rates within those herds have proved to be low - usually around 2 percent to 3 percent.
"We need to get the message out that we're the victims, not the cause," said Ron Walker, president of the Colorado Elk Breeders Association. "We firmly believe the elk industry has taken a proactive approach to this thing from the beginning."
In Colorado, there is also a historical riddle involved in the elk ranch part of the CWD mystery.
In the 1980s, ranchers were allowed to purchase New Zealand red deer, more readily available than wild elk and an easier way to get into game ranching. Local wildlife advocates objected, fearing the imports would breed with native elk and dilute the gene pool.
At about the same time, the wildlife division kept mule deer infected with CWD at its Junction Butte facility near Kremmling until 1985 when they were killed.
The pens stayed empty until 1991, when elk confiscated from an individual who had stolen them from the wild were placed in the pens for about six months.
The state worked out a deal to trade the elk to ranchers for their red deer, one-for-one, so that the alien stock could be destroyed.
"Then, after we thought about it, we decided that wasn't such a good idea," Miller said. But the second-guessing came too late. The state paid $70,000 to buy back as many of the Kremmling elk as it could, but some had already been sold. Miller said 13 of the repurchased elk were tested for CWD. All 13 were negative.
But some elk ranchers believe to this day that is the way the killer crept into their herds.
CWD BREACHES THE ROCKIES
On March 29 of this year - the afternoon of Good Friday - with the state Capitol nearly deserted of both lawmakers and reporters, Gov. Bill Owens hastily assembled directors of three state agencies, called a press conference and dropped a bomb.
The news: Chronic wasting disease had been discovered on the Western Slope, a possibility scientists and politicians had feared with equal dread. On this day, what had been a relatively obscure wildlife disease affecting mostly the state's wind-swept eastern prairie blew up into a front-burner political, scientific and economic crisis.
As it happened, the two wild deer that tested positive for the disease were found inside the fences of an elk ranch, the Motherwell, south of Craig.
Since that time, two more were found inside and six free-ranging deer outside the ranch's fences have tested positive.
The killer is loose in the wild on the Western Slope, which has brought the governor to the fore.
"This was more of a scientific and esoteric issue before it broke through on the Western Slope," Owens told the News.
He said, however, when CWD appeared southeast of Craig, the issue rose to a different level.
"I didn't speak out before because I try to be careful not to use this office to mobilize issues until it's absolutely necessary. I don't want to 'cry wolf,' " Owens said.
Owens warned that the Western Slope outbreak could cost the state "hundreds of millions of dollars."
The governor's math is well-grounded. There are an estimated 550,000 deer and 270,000 elk in Colorado, making the state a premier area for hunters and watchers of wildlife. Both are big business.
Hunters pump an estimated $600 million into local economies each year, according to an economic impact model prepared for the Division of Wildlife. That takes into account the purchase of sporting goods equipment, lodging, gasoline and other related goods, services and incidentals.
Additionally, the sale of hunting licenses accounts for most of the wildlife division's $85 million budget.
The popularity of elk - and the tourist dollars they draw - is exemplified by the 730,000 visitors to Rocky Mountain National Park during September and October each year when the bulls bugle during rutting season.
To understand just a slice of the economic impact, visit Craig, a classic Colorado hunting town in the state's northwestern corner. There, in the days and weeks after the Good Friday bombshell, chronic wasting disease dominated the conversation.
From butcher shops to coffee shops, in talk across the counter, and the table, locals spoke of their dread at the arrival of a disease that could wipe them out - even if it doesn't kill them.
At the Golden Cavvey restaurant, the town's most popular gathering spot, manager Sharon Bell lamented that this new wildlife disease may drive away the hunters that pour in every fall from Missouri, Wisconsin, New York, Texas, "everywhere," Bell said.
"They always want the biggest steak we have," Bell said, smiling as she explained the money the hunters pump into the town - and not just on food. Money is spent on clothes, hotels, equipment and supplies - even jewelry to ensure a smooth return after leaving spouses behind for two or three weeks of hunting.
"It's going to hurt, and not just Craig," she said. "It's going to hurt all of Colorado."
Just a few blocks away, at Mountain Meat Packing, the arrival of CWD means a major shift in strategy for owner Gary Baysinger.
Unwilling to risk contamination of his operation, he's giving up the big money he makes each fall skinning, cutting and wrapping the deer and elk brought from the field by hunters.
How much business will he surrender? In 2000, Baysinger's operation processed 1,300 elk, 850 deer and 500 antelope. Most of his work is beef, so giving up game won't kill the company. The risk is greater, Baysinger said, from CWD.
"Once you get that prion in your plant, there's no getting it out," he said.
Baysinger predicts fewer hunters will converge on northwestern Colorado anyway.
"This is devastating to the economy here," he said, with a direct effect on jobs. At Mountain Meat Packing, for instance, Baysinger usually triples the work force during hunting season - ramping up from 17 employees to as many as 50.
"We have this little saying in Craig: 'When hunting season comes, you're either a processor, taxidermist or an outfitter,' " he said. "It's like slitting your throat if you don't have a hunting season."
Some, like sporting goods store operator James Simos, see the real threat as coming from bad publicity. "It goes from your newspaper to the hunting magazines to the sportsmen in Pennsylvania," Simos said. "It snowballs."
Simos, whose store, he proudly notes, ranks sixth in Colorado in the sale of hunting licenses, believes that CWD is being overblown.
"If they keep finding it here and finding it there - my position is that we've probably had CWD for 50 years. Now we've just put a name on it."
Another fear: In its zeal to eradicate CWD from local deer, the Division of Wildlife is throwing the baby out with the bath water. "They're clearing all the deer out - are they going to put the deer back in?" said Al Shepherd, a plumbing and heating man, gabbing with friends over afternoon coffee.
Ed Wilkinson, a retired phone company man in a Stetson hat, said it took chronic wasting disease to alert state leaders to the importance of places like Craig.
"Isn't it amazing how our governor got involved," Wilkinson says, "when he realizes how much money hunting brings to the state?"
Wilkinson looked at his friend Shepherd, the plumber. He notes that even a guy in Shepherd's line of work isn't immune from the economic effects of a falloff in hunting.
"If someone can't afford to get a (pipe) break fixed, they're going to try to fix it themselves," Wilkinson told Shepherd, "without calling you."
The state responded to CWD on the Western Slope as it has in other areas, proceeding to thin herds in the vicinity of where the infected animals were found. The word "sharpshooter" has re-entered the government lexicon.
THE DRASTIC REMEDY
CWD has ignited a wildlife slaughter that would have seemed the stuff of fiction a few months ago. It amounts to the premeditated taking of the very wildlife that make Colorado what it is.
Government has sponsored large-scale wildlife kills before. Witness the eradication of buffalo, wolves and "trash fish."
But sharpshooting of creatures adored by the public to manage a disease has sparked protest from those who believe it's an overreaction. Plans to kill herds in Boulder County, believed to be the disease's southern boundary, produced emotional political confrontations.
The theory behind it all is simple: Cutting down on the density of herds slows the spread of disease. The animals must be killed in order to save them.
Hundreds of deer have been culled in disease hot spots, but the larger kills are yet to come.
In February, the Wildlife Commission approved plans for the endemic area of northeastern Colorado, calling for culling some 5,000 deer during the next one to three years.
Biologists hope hunters, via loosened restrictions on licenses, can take care of at least half of those.
In one herd, in an area north of Fort Collins, the division will cut numbers in half, from 2,000 to 1,000, to study the relationship between deer density and CWD prevalence. A nearby area in Wyoming will be left alone to compare results.
"We're concerned that allowing those populations to grow will exacerbate the CWD," Rick Kahn, the division's wildlife management supervisor, said of the strategy.
For the first time, herds won't be managed for hunters and wildlife watchers - but for chronic wasting control.
Within the endemic area, the shooters will be looking for hot spots of infected deer, killing all in the small populations where infection rates appear highest, Kahn said. "We're going to try and see if we can snuff out the disease."
Not everyone thinks this is the best approach.
A leading critic is Charles Southwick, a biology professor emeritus at the University of Colorado and formerly a professor of pathobiology at Johns Hopkins University.
Southwick, whose quiet, reasoned eloquence has given him a voice above the crowd of Division of Wildlife-bashers, insists that killing too many deer in areas peripheral to CWD hot zones could have dire effects.
One: Clearing out the deer could spark movement of animals from areas of high infection into "empty" spots, hence spreading the zone of high prevalence.
Two: Taking so many healthy animals to get the relative few that are sick could be playing too aggressively with nature. What if many of those animals that are not carrying CWD turn out to have genetic resistance to the disease? That would be shredding the process of natural selection.
"Natural herds in good habitat show promise of coping with this infection if they are not crowded or unduly stressed," Southwick wrote in a piece published in the commentary section of the Rocky Mountain News.
But the wildlife division - with the support of the governor - doesn't think it can take the chance that the disease will burn itself out.
In a line repeated by several top state officials, they say something like this: "Do we want to look back someday, when the deer and elk populations are obliterated, and wish we'd taken stronger action?"
Tracking the disease over the last six or seven years shows "trends are stable or slightly rising," veterinarian Miller said. "The disease doesn't go away, but it doesn't explode."
But it does spread.
And should infection rates rise only slightly, from the current level in deer of 5 percent to 15 percent of wild animalsin the endemic area, all bets are off.
Even slight increases in infection rates can set off a ferocious rise in deer mortality. If enough adult deer die off, populations could be at risk, wildlife officials say.
Colorado and other Western states are in a race with a mysterious killer.
And the killer, for now at least, has the upper hand.