April 7, 2002 Milwaukee Journal Sentinel by Lee BergquistWildlife ecologist Scott Craven had hoped to talk a little about frogs and spring on a Wisconsin Public Radio program last week.
"But I couldn't get off chronic wasting disease," said Craven of the University of Wisconsin Extension, who is a regular guest on Larry Meiller's midday program.
"It's a huge deal -- everywhere I go, people want to talk about it."
Wisconsin's deer season is more than six months away, but there is growing concern about the disease and how it might affect hunters' annual fall pilgrimage to the woods.
So far, the number of confirmed cases of deer with chronic wasting disease is a tiny fraction of Wisconsin's 1.5 million herd. As of Saturday, there were 12 confirmed cases of animals with the deadly brain disease, all in an area near Mount Horeb in western Dane and eastern Iowa counties. But what troubles many people at this point is what they don't know.
How many of Wisconsin's deer are afflicted by the disease? Is venison made from them safe to eat? How will the Department of Natural Resources react once the extent of the problem is known? And will caution keep many hunters out of the woods this fall, further exacerbating an overabundant deer population and taking an economic toll on business owners who depend on hunters for their livelihood?
Experts say it's too early to say how this will affect the 2002 season.
"Until they have all of the results, we won't know," Craven said. "It might not be until next fall that we can really tell."
Tests are crucial
For now, all eyes are on the outcome of laboratory tests of 500 deer that are being killed in a 415-square-mile area where the first three deer that tested positive for the disease were shot during last fall's hunting season.
The 12 deer that have tested positive represent 4.4% of the 272 samples examined so far by an Iowa laboratory -- about the same percentage of positive results found in an outbreak in Colorado.
What happens next will be driven by the laboratory results. The DNR says that it needs to know more before it can make recommendations on whether more deer need to be killed to thin the herd, or whether the agency needs to focus its efforts on another area.
Depending on the results of the tests, the DNR may have to thin the herd to prevent the disease from spreading. "We will have to look at some method of lowering the population in the area . . . it's going to involve hunting," said DNR spokesman Bob Manwell.
The DNR also is likely to expand testing for the disease to other parts of the state, he said.
"It is important that we get this contained to one area," said David Ladd of Dodgeville, chairman of the Big Game Committee of the Conservation Congress, which advises the Natural Resources Board.
"This is such a big business."
Nearly 700,000 hunters took part in the hunt last year, according to state figures. Hunters killed about 400,000 deer during the nine-day gun season.
While the state Department of Commerce estimates the annual economic impact of deer hunting at $233 million, that's conservative because it doesn't include the sale of clothing, equipment and guns, and other expenses that are made outside of the season. In addition, license fees to the DNR bring in nearly $25 million.
Deer are woven deeply into the fabric of the state, if only because of their sheer prevalence. Motorists on average kill 40,000 deer on highways each year.
Once confined to the northern third of the state, the deer population has moved south over the past 50 years, according to Craven.
"The popular misconception is that they were trucked down from the north, and that the DNR had something to do with it," he said.
Rather, southern Wisconsin has "wonderful deer habitat, and the few deer that were here have responded to it," Craven said.
Hunters want to know more
For deer hunters, the outbreak of chronic wasting disease -- the first east of the Mississippi River -- is an awakening.
"There has never been anything like this before -- everything pales in comparison," said Glenn Helgeland, who runs the annual Wisconsin Deer & Turkey Expo at the Alliant Energy Center in Madison. The three-day event ends today and was expected to draw 35,000 people.
After laboratory results in February showed that three bucks near Mount Horeb had the disease, expo staff and the DNR quickly added five seminars about the ailment to feed hunters' growing appetite for information.
On Monday night, the disease is again expected to be a hot topic at the DNR's spring fish and wildlife rules hearings and the annual Conservation Congress meeting.
The joint meetings are expected to attract 7,500 to 10,000 people total in every county of the state. Chronic wasting disease is not on the agenda, but officials expect that hunters will ask questions about it.
In a period of uncertainty, some are not sure they want to eat the venison from last year's hunt.
Richard Dickman, owner of Dick's Quality Meats in Mount Horeb, said about 25% of the people he has talked to have already thrown out last year's meat.
Dickman cut and packaged 1,000 deer last season, and 1,200 the year before.
"Pretty much everybody is talking about it," he said.
The disease could change the way deer are processed next year. A power saw lets Dickman cut up a deer in 10 minutes, but he said butchers might be forced to use knives -- a more laborious and expensive process -- to steer clear of the spinal cord and lymph nodes where the disease is found.
"The wives are going to make the decision as to whether the meat is going into the freezer," said Ladd, a deer hunter for 50 years.
Chronic wasting disease results in weight loss and behavioral changes in the animals. Although it is still uncertain which infectious agent causes chronic wasting disease, prions -- abnormal forms of protein -- are the most likely suspects.
The most widely known prion disorder, mad cow disease, can spread to humans. The World Health Organization has said there is no scientific evidence that chronic wasting disease can infect humans. But it also says no part of a deer or elk with evidence of the disease should be eaten.
Also, at least two studies have raised questions about whether the disease could end up in the meat.
Last month, a research team led by Nobel Prize winner Stanley B. Prusiner of the University of California in San Francisco reported that a study showed that abnormal proteins linked to mad cow disease were found in the muscle of mice. Until his study, evidence had suggested that prions stayed out of muscle and remained in the brain, spinal cord and lymphatic tissue.
Prusiner said more research is needed.
Another study, by the Rocky Mountain Laboratories in Hamilton, Mont., found that chronic wasting disease prions could convert to human prions.
Sarah Shapiro Hurley, a DNR veterinarian, said the research in both cases is different from what is happening in Wisconsin.
Prusiner's work did not deal directly with mad cow disease but was a strain for hamsters that was injected into mice, she said.
And the Rocky Mountain study was done on the cellular level outside the body of an animal, she noted.
But she is not a critic of the research.
"These are obviously things that the public needs to be aware of," Shapiro Hurley said. "We don't want to make this all pure and rosy and for people not to worry their pretty little heads. But the risk is relatively low."
The deer now being killed within a 10-mile radius near Mount Horeb are going to a Dane County landfill. Because prions, which attack the brains and nervous systems of elk and deer, don't die, they will remain in the landfills.
But landfills are capped, and the prions won't pass through the landfill filters, so there is no danger that the diseased carcasses will infect other animals or somehow get into ground water, the DNR says.
As a protective measure, some leaders in Wisconsin's hunting community are calling for testing of all deer during the 2002 hunt, with hunters paying an extra $25 or $30.
"It's not possible," Shapiro Hurley said.
Even though the government is adding new labs, she said the country would still lack the capacity to handle hundreds of thousands of deer at any one time.