Southeast Minnesota still battling CWD

TCR/SCOTT BESTUL Minnesota DNR biologists were on hand in Rushford to test deer for CWD on November 9, opening day of firearms season. This was the first year of mandatory CWD testing in the area for whitetails taken in any hunting season.
Chad Smith

Southeast Minnesota deer season is underway and that means time spent outdoors, chasing the wily whitetail. However, it also means more dealing with chronic wasting disease in the area’s herds.

Barb Keller, Big Game Program supervisor with the Minnesota Department of Natural Resources, says southeast Minnesota is unfortunately still in the epicenter of the state’s CWD outbreak.

“We continue to find more deer testing positive for the disease,” she said. “To date, we’ve had 54 positive tests and all but one of them came from the southeast part of the state. It’s certainly disappointing that we continue to find positive deer. The one good thing is the positive tests are clustered in certain areas and we’re not seeing it spread at a high rate outside of those spots.”

Keller says the DNR is “frustrated” by just how hard CWD is to combat. It’s caused by a “misfolded protein” instead of a virus, bacteria, or fungus, all things that are much easier to eradicate. She said the misfolded protein then causes other proteins to misfold throughout an animal’s body, causing the death of neurological tissue.

“That ultimately causes the death of an animal,” she said. “These misfolded proteins are very difficult to deactivate.

“An infected animal will also shed those infected proteins (prions) into the environment, where they can stay active for a long time. The prions enter the environment through an animal’s saliva, feces, or urine, and another animal will be infected by coming into contact with those excretions.”

Another big challenge in battling CWD is the long incubation period. She says most of the deer that tested positive in southeast Minnesota never showed any outward signs of infection.

“A deer can be infected and shedding those infected prions, infecting other deer, and yet not showing any clinical symptoms,” Decker said. “The incubation period can be up to two years long between the time an animal is infected and when they show clinical symptoms. In most cases, hunters had no visible indication that the animal was sick at all.

“That’s what makes it so important for hunters to get their deer tested,” she said, “instead of relying on whether or not their deer looked healthy.”

She says all of these factors make CWD a difficult disease to control, and there isn’t any cure or vaccine available right now. Scientists are working hard on finding a cure for CWD or a vaccine that would work in a live animal. “Unfortunately, science isn’t there yet,” Decker added.

Scientists first detected chronic wasting disease several years ago in Colorado. “They don’t know what caused that first misfolded protein that started the disease on a path to making its way into deer herds around that state,” she said. “We do know it’s a similar prion disease to scrapie, which affects sheep, as well as bovine spongiform encephalopathy, or ‘mad cow disease.’”

So, what does a continuing battle against CWD mean for deer hunters in southeast Minnesota? To put it simply, it means testing.

“Regulations require them to get their deer sampled if they’re in one of our CWD management zone permit areas,” Keller said. “Not only do hunters need to get their deer sampled, but we also have regulations that prevent the movement of whole carcasses outside of those areas. That’s another way the disease can spread.”

The DNR will get test results back as quickly as possible. A big number of deer are harvested during the opening weekend, which means an influx of CWD tests and a little extra time to get the results.

“We send the samples to a lab in Colorado,” she said. “With them getting a high volume of samples, it’ll take them a little longer to get through that workload. We’re estimating between four to eight business days to get the samples back for hunters.”

As far as science knows, CWD hasn’t yet jumped the species barrier between deer and humans. However, Decker says health officials are worried about the possibility. “Officials want hunters in the CWD management zones to make sure and get their deer tested,” she said. “They also do not want hunters to consume a deer that tests positive.”

The DNR has a website that hunters can go to and see their results. However, if a deer does test positive, the DNR will give that hunter a call to let them know directly.

“We want to know what happened to the deer’s carcass, and we’d like to come and dispose of the carcass properly,” Decker said. “If they already have the meat processed, we’ll come and pick that up too.”

Her final piece of advice to hunters in southeast Minnesota is to make sure you are aware of the DNR’s changing deer management zones.

“The reason is those boundaries have changed this year,” she said. “Don’t assume you aren’t in one this year because you weren’t last season. Do a quick check online to make sure you aren’t subject to these regulations

“We’re also offering more bag limits in these areas. Disease management permits are available for $2.50. Hunters in these management areas can purchase these instead of the more expensive bonus tags. I would encourage them to take advantage of those permits and harvest some does in those areas.”