Concerns have grown about the spread of a deadly disease through Wisconsin’s deer herd, but most hunters have remained unfazed about eating tainted venison.
Chronic Wasting Disease is related to incurable illnesses that cause dementia and death in humans, but CWD itself hasn’t crossed the species line, so most hunters don’t take advantage of free testing offered by the state.
In the months leading up to Saturday’s start of the nine-day season for hunting deer with guns, more hunters have expressed concerns about how CWD will affect the herd, but only a few thousand of the 300,000 or more deer harvested each year are tested.
Attitudes about testing vary widely among hunters, but there’s been no indication that testing will become radically more popular this year, said Larry Bonde, a Manitowoc farmer who serves as chair of the Wisconsin Conservation Congress, which advises the state Department of Natural Resources.
“There are people who know the deer they shot have CWD and they don’t care, and others who aren’t anywhere near the CWD areas and they test everything,” Bonde said.
About 40,000 samples were tested in 2002, the year the disease was detected in Wisconsin a few miles west of Madison, but the numbers dropped off in 2006 as testing became less convenient amid budget cuts and shifting policies.
Samples submitted for testing hit an all-time low last year when the state switched to an electronic system for registering harvested deer and reduced in-person registration at sites where DNR personnel encouraged hunters to provide samples for testing.
Scientists lament that they have less data than ever about CWD as its prevalence reaches new heights in the core outbreaks in southern Wisconsin and appears in more and more counties miles away.
Bonde said he would consider testing if he hunted where CWD had been found, but it hasn’t been detected in the wild near his usual spots in Manitowoc County and Calumet County.
The state Department of Health Services recommends against eating venison from deer that test positive for CWD or show signs of illness — such as emaciation or abnormal behavior.
The World Health Organization and the U.S. Centers for Disease Control and Prevention haven’t found CWD in humans, but the disease has similarities to others linked to proteins called prions that create incapacitating microscopic holes in mammals’ brains.
The unpredictable prions can mutate, often incubate in an animal for years before symptoms appear, and be spread by animals genetically resistant to symptoms. In the mad cow disease outbreak that swept through cattle herds in the 1980s, prions in beef led to dozens of people dying of another prion illness — a variant of Creutzfeldt Jakob disease.
“No one can predict with absolute certainty that CWD will never cause human disease,” said Jennifer Miller, a DHS spokeswoman. “It is because of this uncertainty that DHS, WHO, and CDC recommend that people should not consume any part of a deer or elk with evidence of CWD.”
DHS tracks cases of human prion diseases like Creutzfeldt Jakob and compares them to a registry of people who eat venison, but hasn’t found any matches, Miller said.
Whitetails Unlimited president Jeff Schinkten of Algoma said the organization encourages hunters to test venison from counties affected by CWD.
“The risk is low, but with more testing maybe we can learn more about it,” Schinkten said. He said he’ll hunt with his granddaughter on Saturday in Door County where the disease hasn’t been found.
“We’re living in the good old days,” Schinkten said. “If they tell me there’s CWD prevalent in my county, I would get it tested.”
In southern Iowa County, Miles Narveson lives and hunts a short distance from the center of the Wisconsin outbreak where 30 percent to 40 percent of the herd is believed infected, but he doesn’t test the venison he eats.
“The risk is very small,” said Narveson, who serves on the Conservation Congress in the county. “It’s probably riskier me walking down the hill and slipping on the snow.”
Narveson said he suspects most hunters he knows would test a deer if it looked sick.
To the southeast in central Green County, Kenneth Risley said he tests as a precaution even though there have been no cases in his area, away from the Iowa County and Dane County borders.
Risley said he is aware of research showing that prions can linger indefinitely in soil, animal scat or urine, and in plants. A crow could pick at the carcass of an infected deer, and then fly miles before depositing the disease in a new place, Risley said.
Risley is chairman of the County Deer Advisory Council in Green County, but he said he wasn’t speaking on behalf of the group. The councils were set up to advise the DNR on deer hunting.
“Most people don’t get it tested because testing isn’t always so handy to do,” Risley said. “You have to drive a ways.”
The DNR allows hunters to drop off deer tissue for testing at sites determined each year by budget limitations and changing surveillance goals.
Mike Samuel, a UW-Madison scientist who specializes in CWD research, hunts on land he owns in the southwest corner of Dane County. He said he tests every adult deer he shoots, even though it has meant having to dispose of three that were found to be infected in recent years.
Instances of human prion diseases are rare, so people aren’t accustomed with them, but they are frightening, Samuel said.
Prions can’t be reliably cleaned or washed away, and the incurable diseases involve people losing their minds before death, he said.
“We don’t know very much about what the future can hold,” Samuel said.
Lee Fahrney, who lives and hunts on land he owns in southeastern Iowa County, said he almost always tests for CWD. He said he and his family and friends have shot five infected deer on his property in recent years. Two were obviously sick, but the others looked fine.
One dressed out at 200 pounds, he said.
“Personally I wouldn’t eat a deer if it comes back positive for CWD,” Fahrney said. “But I know there are a lot of people who aren’t that worried about it.”