Fanning the Flame: An Aggressive New Approach to Combat Chronic Wasting Disease
Chronic wasting disease is changing the landscape of hunting. The percentage of the US public that hunts is declining, along with funding for conservation efforts. Is the decline in hunting related to the negative press written in regards to CWD? Fear about the potential spread of Chronic Wasting Disease (CWD) has caused some state agencies to allocate money that was used for conservation and habitat management into testing for CWD, while other states force hunters to spend their own money to test deer for CWD. In Minnesota, for example, if you shoot a deer within the CWD zone in Southeast MN, the DNR will test it at no charge. If you harvest a deer in Southwest Minnesota, the DNR suggests you send the sample into the University of Minnesota diagnostic lab for testing, which costs about $26.25 plus shipping.
The unfortunate truth is that monitoring for CWD does NOTHING to prevent the spread. Just like the commercial with the security monitor that tells everyone the bank is being robbed, but doesn’t do anything about it because he is only a security monitor. That is what CWD testing accomplishes. The reason CWD keeps spreading is because there have not been any successful attempts to curtail prevalence in areas where the disease is established. Wisconsin was the first state to attempt wide scale CWD culling efforts, but their effort was not sustainable because they lacked public support. People did not want every deer shot off the landscape (Can you blame them?).
Here I propose a technique to lower CWD prevalence on the landscape. It is not cheap, but it’s better than wasting money testing for CWD when the test results are not useful in lowering prevalence rates.
Here is the list of things that have never been tried in endemic areas of CWD:
1. Increase the amount of supplemental feed and mineral sites available on the landscape. There are two theories as to why this seemingly crazy idea might actually work. One is that CWD might be related to metal ions switching places in a prion, and increasing the amount of copper in the diet of free-ranging deer might lower prevalence rates. The other theory is that feeding deer will increase contact rates and speed up disease progression. This is equivalent of lighting a fire in the path of a wildfire so that once the wildfire reaches that area; the impact will not be as severe. There is evidence for a genetic resistance, although nature would take hundreds of years to “thin out the herd,” this strategy might hasten the process. Prevalence rates would initially spike, but as more deer with resistant genes become present on the landscape, disease rates would actually lower in the long term.
2. Move funding for CWD testing into research for the CWD vaccine. Did you know that a vaccine exists for CWD, but it is currently not cost effective enough to use on free ranging deer? Researchers at the New York University School of Medicine have been able to PREVENT a deer from ever getting CWD by altering the genetics of bacteria in their stomach to digest harmful CWD prions before the body lets them enter the nervous system. The problem? 4 out of 5 of the deer they tried to give the vaccine to, still contracted CWD, but it took them longer to die from it, so in reality they were spreading infectious prions for longer than a deer that would have died naturally. I have spoken to the lead research scientist on this project, and they have already been working on getting this vaccine refined so that it’s more efficient. Could you imagine if the technology of this vaccine could be placed into a deer feed so that deer would never be able to uptake the infectious CWD prion? What would states do that are currently in a feeding ban?
3. Stop allowing bucks to reach ultra-maturity. In every location that has CWD, older males carry the disease at a higher prevalence than younger males. This strategy will not be popular with trophy hunters, but if they truly want to lower prevalence they will have to decide: is having a bunch of old deer on the landscape worth having a high prevalence of CWD? In most areas, hunters would rather see older bucks than worry about a disease that does not currently effect humans. My opinion is that we don’t need 7.5 year old bucks in a herd, especially if we feed them correctly because these bucks will be trophies at 3.5 and 4.5 years old (ever hear the world record Hansen Buck’s estimated age?).
The biggest fear with CWD is that someday the disease will mutate into one that will infect humans. Currently, only Macaque monkeys have been shown to contract the disease, but those specimen were force fed CWD tainted meat over a long time period in order to show clinical symptoms of the disease. With the amount of people in Wisconsin and Arkansas consuming venison without ever testing it for CWD, many people have been ingesting CWD positive meat for decades with no ill effects. Studies have shown that currently the species gap is too large for humanized mice to contract the disease, but some are worried that it’s only a matter of time. I certainly don’t want to be the case study as to the effect on humans if it does jump the species barrier and we all become the walking dead, but let’s be realistic about the risk. You are roughly a million times more likely to die in a car accident on your way to work each day than becoming infected with CWD. If we are truly concerned with lowering human death loss, cars, planes, bikes, cigarettes, and laundry detergent pods would all be banned.
In my opinion, the best thing you can do if you hunt in an area that has CWD, is to not move the carcass after the kill. Learn how to quarter out and debone meat in the field, and do not carry the intact skull out with you. If it’s a trophy that you want mounted, learn how to cape a deer in the field. After you cape it out, do a v-cut on the skull and remove any brain tissue, so you do not contaminate another area with CWD prions. Another thing we can do to help slow the spread of CWD is to make sure your taxidermist is properly disposing brain material in a landfill. Some taxidermists simply dump animal parts back on the landscape to let “nature take care of decomposition,” when in reality, they are just helping the prions spread into areas that they might not have ever gotten to naturally. State transportation agencies also need to properly dispose of roadkill and not use wildlife management areas as decomposition sites (this happens more than you think).
The last thing we can do to prevent CWD from spreading; is to stop moving live animals from one place to another. You can do all the testing you want before an animal is shipped, but there is no guarantee that animal is CWD free. It is a shame that deer breeders and farmers have had the finger pointed at them for spreading CWD, but there have also been cases where state agencies have moved animals around that helped CWD spread. There are even instances where CWD pops up in an area with no deer breeder within 100 miles, so they are not always the culprit. I won’t lose sleep over CWD spreading into areas that it has never been, and I don’t know if there is anything I can do to try and convince state agencies to shift their funding for testing into more proactive avenues outlined above. Only time will tell what improvements will be made with long term CWD management.
– Tim Neuman, Wildlife Biologist