Recently the DNR announced the first case of chronic wasting disease (CWD) in a six year-old free range doe in Ingham County. CWD belongs to class of diseases called transmissible spongiform encephalopathies (TSE).
All TSE are prion diseases, and prion diseases are notable for turning brains into to swiss cheese. Mad cow disease and something humans get called Creutzfeld-Jakob syndrome are examples. They are all deadly.
Prion disease isn’t caused by a virus or bacteria. No one knows exactly what causes these diseases, but usually a build up of damaged proteins is found in the brains of animals and humans with this disease.
TSEs are virtually indestructible. Forget radiation, heat, and bleach. And by heat, I mean flames. No matter how much you burn your steak, if it’s infected with mad cow, you aren’t safe.
In the wake of this somewhat dismal news, nearly everyone has questions.
Can Humans Contract CWD?
The short answer is , “No, probably not.”
So far, there’s no proof that a human has ever contracted the disease from a deer. Even if they did, it would be immensely difficult to prove. The disease takes years to incubate, and symptoms resemble dementia.
The day after I discovered that we had CWD in our deer herd, I mentioned it to my doctor. His wife had died of the human version of the disease. He claimed that there was a 21 year-old at U of M with the disease who they thought had possibly gotten it from eating venison in a state where deer are contaminated. Again, this would be virtually impossible to prove.
Encouragingly, states with high rates of CWD do not seem to show any correlation between deer prion disease and human prion disease. Still, caution is suggested.
Can Other Animals Get CWD
According to studies, if you inject it directly into their brain, some animals can get it, including cats. “CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to-feline transmission in nature,” was the study’s conclusion. Again, it was directly injected into the cat brain, so who can know.
A mountain lion was fed infected carcasses for years and didn’t contract it.
So far, no realistic evidence of cow-to-cervid transmission or vice-versa has been found.
Which Areas Are Affected
What Is The DNR Doing About It?
The DNR has drawn a ten mile circle around the area in Haslett Township, Ingham County, where the deer was found. They have been testing deer within that circle for several weeks as of the date this article, and no others have come up. See a sidebar for the regulations for affected areas.
If another deer is found, they will again draw a ten mile perimeter and re-focus their efforts.
The DNR is doing an excremental ton of work. They are shooting and hauling in deer in the area for lab tests. It’s critical to determine how far the disease has progressed. They’re fielding endless calls from people concerned about the disease, and calls from people who hate the thought of shooting deer at all, as well.
When Was The Disease Discovered?
In Fort Collins, CO, around 1967, researchers were studying TSE in sheep. According to one of the biologists, Gene Schoonveld, the deer and sheep were penned together from 1968 to 1971. About three dozen deer died of what later would be identified as classic CWD symptoms. Many of the penned deer were released into the wild.
Since then it has spread to wild deer populations in 19 states.
How Did It Get Here?
That is the great mystery.
It could have been transmitted animal-to-animal. There’s a map on the DNR website that shows where else CWD has been found in the country. Basically if it were transmitted from animal to animal it would show up as a chain of cases from Wisconsin, through Chicago to Michigan. Since that’s not the case, that’s the least likely scenario.
It could have arrived through infected deer urine that a hunter used as an attractant. This scenario is fairly unlikely, but is being investigated.
Nearly half the hobby farmers/petting zoos in Michigan ten years ago are no longer in business. A hobby deer farmer could also simply have quietly released their deer.
Finally, it could have arrived via a carcass or animal parts. Non-hunters don’t understand this explanation. Hunters know – people hunt out-of-state and bring bodies, heads, whatever back all the time. Then they dump it.
Remember that little fact about prions being indestructible? There’s strong evidence that they basically form a biofilm on plant roots and other areas where an infected animals may have left saliva, blood or feces.
So a dumped carcass could deteriorate but the prions could remain for years, “waiting” for an unsuspecting deer to munch some undergrowth.
Local dumpsites have been tested, the soil tested and so have all carcasses found in the area
Odds are we will never know, but it won’t be for lack of trying.
In the meantime, every forest trail, backyard and flower bed that deer came in contact with is contaminated.
How Long Does It Incubate?
An infected fawn could spread the disease for years before it showed symptoms.
What Are The Symptoms?
As mentioned, they may go years without symptoms. When they do show up, they vary. Deer can lose their fear of humans and cars. This is the reason the DNR is testing all the roadkill deer in the area where the infection was located. It’s a great place to start looking. Deer may also stagger or appear starving. They may excessively salivate.
If you see a deer with these symptoms in the tri-county area where the first deer was found, call the Wildlife Disease Hotline 517-614-9602 immediately.
What Will This Do For The
Future Of Deer Hunting?
It may not affect your hunting immediately. It will affect future generations of hunters. It will take 30-40 years, according to models.
The concept of QDMA may ultimately need to be reconsidered, because older bucks are the deer most likely to be highly contaminated.
Is There Nothing At
All That Destroys Prions?
Nature actually has a solution, and we are on our way to discovering it. Perhaps. A 2012 study published in Pubmed claims, “We have now tested more than twenty lichen species from several geographical locations and from various taxa and found that approximately half of these species degrade prions.”
What Can I Do To Help?
Great question. First, don’t panic. If you live in the affected area, follow the rules to a “T.” No kidding, skip no steps. Affected areas are required to turn the heads in for testing, which will take a week. Only licensed butchers are allowed to handle meat taken in that area.
If you don’t, consider using only deer urine products made in Michigan from licensed facilities. High-fence facilities in Michigan are highly regulated – tested tens of thousands of times by the DNR for CWD. If there is CWD in their herd (which happened once in 2008), they are the first to know and take action.
Conquest Products has taken the step of having their products certified CWD and TB free.
Report deer that are acting strangely. Don’t ever bring an out-of-state deer or elk parts back to Michigan and dump them. And urge your representatives to vote for extra funding for the DNR if they ask for it to deal with this scourge.
Hunters will play a key role in how this affects our state – from taking out potentially infected deer and/or reporting them to following guidelines to keep the herd safe.