Where has chronic wasting disease been found in Wisconsin, how to test for it, and answers to other questions

As fall hunting seasons slowly start to begin in Wisconsin, discussions and questions arise once again about chronic wasting disease and its prevalence in the state.

Discovered in the 1960s, the fatal disease for deer and similar species has infected herds all over the country.

Whether you're hunting or wanting to learn more about the disease, here's what you need to know.

What is chronic wasting disease?

Chronic wasting disease (CWD), is a fatal, infectious nervous system disease of deer, moose, elk and reindeer/caribou, according to the Wisconsin Department of Natural Resources. It only occurs in members of the cervid or deer family, both wild and captive.

CWD belongs to the family of diseases known as transmissible spongiform encephalopathies (TSEs) or prion diseases. Prions are misshaped proteins that can spread the disease through direct animal-to-animal contact or in the environment through bodily fluids or carcass parts of an infected deer. Prions are extremely resilient and capable of remaining in the soil for years, potentially infecting several deer from a single source.

What are the symptoms of chronic wasting disease?

Infected deer can appear healthy for months before showing signs of illness. Symptoms can include drastic weight loss, drooped head and ears, loss of coordination, excessive salivation and reduced fear of humans, according to the state DNR.

Is there a vaccine for herds with CWD?

No. There is no vaccine or cure for CWD-infected animals.

Can humans contract CWD?

According to the Centers for Disease Control and Prevention, there have been no reported cases to date of CWD infection in people. However, the CDC notes that some animal studies suggest CWD can pose a risk to certain non-human primates, like monkeys, that eat meat from CWD-infected animals or come in contact with brain or body fluids from infected deer or elk.

The World Health Organization has recommended that it is important to keep the agents of all known prion diseases, like CWD, from entering the human food chain.

Has chronic wasting disease been found in Wisconsin?

Yes. The Wisconsin DNR has monitored for CWD in the wild white-tail deer population since 1999. The first positive cases were discovered in 2002.

Most recently, a captive white-tailed deer at a Washburn County shooting preserve has tested positive for chronic wasting disease, according to the Department of Agriculture,​​​​ Trade and Consumer Protection.

Where found, CWD typically increases in prevalence and spreads in area. As of this September, it had been documented in 31 states, four provinces of Canada and several other foreign countries, according to the National Wildlife Health Center of the U.S. Geological Survey.

How do you prevent the spread of chronic wasting disease?

The DNR recommends following all baiting and feeding bans and refraining from baiting and feeding in areas where no bans are in effect. 

Baiting refers to the intentional placement of any material, including food, scented materials, salts, minerals and grains, to attract wild animals for hunting purposes. Feeding is the deliberate placement of material used to feed or attract wild animals for non-hunting purposes, including recreational and supplemental feeding, except as allowed for birds and small mammals.

Baiting and feeding encourage deer to congregate unnaturally around a specific location, creating an environment where infected deer can quickly spread diseases like CWD through direct contact with healthy deer.

Additionally, infected deer can leave behind infectious CWD prions in their saliva, blood, feces and urine, which puts healthy deer that visit that site later at risk.

The state DNR imposes various baiting and feeding bans around the state. Counties fall under a three-year baiting and feeding ban when a wild or farm-raised deer tests positive for CWD in the county. If the CWD-positive deer is found within 10 miles of a county line, the adjoining county will fall under a two-year ban. If additional CWD cases are found during the lifetime of a baiting and feeding ban, the ban will reset for an additional two to three years.

You can find the complete baiting and feeding regulations for Wisconsin on the DNR website.

How can a hunter get their deer tested in Wisconsin?

Wisconsin offers free CWD testing for deer harvested in the state. There are four ways to get your deer tested via the state:

• Self-service kiosks: These kiosks are located around the state and are open 24/7. Locations are added throughout the hunting seasons, especially ahead of the nine-day gun deer season. Hunters can drop off their adult deer’s head with 5 inches of neck attached for testing. You can find kiosk locations on the DNR website.
• In-person with cooperating meat processors, taxidermists and other business owners: You can find more information here.
• At-home lymph node extraction: Hunters can extract the retropharyngeal lymph nodes themselves for CWD testing. For this, hunters must pick up a sample bag from a CWD kiosk around the state. There are step-by-step extraction instructions available on the DNR website. The sample bag must be returned to a CWD kiosk.
• By appointment with DNR staff: Appointments can be made by contacting the DNR Wildlife Switchboard by emailing DNRWildlifeSwitchboard@wisconsin.gov or calling 608-267-0866. You will need to leave a message with the switchboard staff. In your message, the DNR asks you to include:
  • The county you are located in.
  • Your preferred dates and times.
  • Your contact information.
• Testing is also available for a fee through private veterinarians (the state DNR has a list here) or the Wisconsin Veterinary Diagnostic Laboratory for sampling.

How does sampling work?

According to the Wisconsin DNR, you should take your deer to a sampling station as soon as possible after harvest. If you choose not to bring the full carcass, remove the deer's head with five inches of neck attached. Heads can be brought to a sampling location up to five days after harvest if kept refrigerated (at 35°F to 45°F) or longer if frozen.

If you harvested a buck and would like to keep only the antlers, you may skull cap the deer after registration and prior to bringing it to a sampling station. If you are using a self-service kiosk, you will be advised to remove the antlers before placing the head in the dropbox.

You can find more information about testing and testing sites on the DNR website.

How long does it take to get results?

Results are typically available 10 to 14 days after the deer is brought to a sampling station, the state DNR says.

What do you do if you have a positive CWD test?

When there is a positive CWD test, the harvester will be notified via their GoWild account or via letter if no email address is not provided. While the CDC states there have been no reported cases of CWD infection in people, the Wisconsin Department of Health Services recommends that people only consume venison from healthy-appearing deer with test results indicating that CWD was not detected.

The state DNR also recommends that you clean all of your equipment used to process the deer with soap and water to remove all organic material and rinse with water. For non-steel items, soak in a 50/50 solution of bleach and water for an hour. For steel items, soak for a minimum of five minutes.

You can find more information on the DNR's carcass handling page.

What if you harvest a deer outside of Wisconsin and want to bring it into Wisconsin?

Whole carcasses and parts of carcasses from states and Canadian provinces where CWD has been found (find a list here) are not allowed into Wisconsin unless taken to a licensed meat processor or permitted taxidermist within 72 hours of entry into Wisconsin.

As for moving deer out of a state, there are other states' carcass restrictions you will want to know as well. You can find many of those here.

Are there other things hunters can do?

The DNR has Adopt-a-Kiosk and Adopt-a-Dumpster volunteer programs that hunters, businesses and groups can assist with at different levels to help with the collection and testing processes in the state.

You can find more information on these programs on the DNR's website.

How can you find where positive CWD tests have been found in Wisconsin?

The state DNR keeps a prevalence map updated on its website. You can also find a map of where CWD has been detected in the state.

Drew Dawson can be reached at ddawson@jrn.com or 262-289-1324.