View Full Version : Chronic Wasting Disease.
June 18, 2005, 10:53 PM
I noticed a peice in this month's Feild and Stream about CWD beginning to spread in upstate New York.
I was also told by "pappy" over the phone that our local extension office in TN has noticed an increase in the number of deer reportd with CWD there, too.
Any thoughts on CWD? What areas are the worst and what can we (hunters and sportsmen/woment) do about it?
Does anyone know of any control measures, nutritional supplements, or food sources that can be used to slow/stop the spread of CWD?
I would happily dedicate a few acres of plot at home to plant soybeans/corn/etc, and add some mineral blocks or feed supplements if that would help. (Not to hunt over, mind you :( )
June 18, 2005, 11:19 PM
Hi - that's an interesting issue. I don't know enough about these diseases yet to be able to comment on a course of action. Certainly, what is known is that they are caused by an unusual protein form, called a "prion" that has a shape that is different than the normal form, due to a different folding arrangement (or conformation). Oddly enough, from what I have read in the past, physical contact of this abnormal conformer with the normal one causes the normal one to spontaneously rearrange to the pathologic form. This is an infectious disease.
Your suggestion of dietary supplements may be useful - if the immune system can play a role in combating this disease, as it does in most infectious diseases. In such cases, providing e.g., vitamins act as "supportive treatment" to boost the immune system's strength and effectiveness - there are other more potent agents that can be given by injection to do this.
Other methods of controlling the spread include culling the diseased animals and burying their carcasses, and isolating live herds that have some infected members from others, using for example fencing (a type of quarantine strategy). It's important to understand the mechanisms of transmission well to do this kind of thing most effectively.
This sort of thing can of course be controlled much more easily in domestic animals (Mad Cow Disease, Scrapie) than wild animals. I'll let you know if I can find out more that is relevant to your question.
Below is an image of CWD distribution in North America in December 2004 that I got from Wikipedia:
...and here is a link to their article on it:
June 18, 2005, 11:41 PM
Here is a great article on CWD that has relevant information - it comes from the April 2004 issue of the open access journal PLoS Biology, and is entitled "Chronic Wasting Disease — Prion Disease in the Wild". It's not very technical in nature:
June 19, 2005, 12:17 AM
38splfan: Your suggestion for supportive treatment was definitely a reasonable one, but in the article in PLoS Biology, they state:
Because normal and abnormal prions have identical amino acid sequences, the immune system neither recognizes an infection nor mounts a prion-specific response. Accordingly, an antibody specific to prions has not yet been identified.
So, no, supportive treatment would not be effective in this case... Where shooters potentially can help would be in assisting with monitoring efforts. It's very important for the scientists to know what the geographical distribution of the disease is, what it's rates are, and to follow these over time.
Certainly, if shooters see deer that are exhibiting symptoms of CWD:
...the deer, which became listless and showed signs of depressed mood, hanging their heads and lowering their ears. They lost appetite and weight. Then they died—of emaciation, pneumonia, and other complications...
... they should notify the appropriate authorities at the least. Note the section: ... at the University of Wisconsin in Madison. Nevertheless, when three white-tailed deer shot by hunters in the south-central part of that state during the fall of 2001 were diagnosed with CWD...
So apparently there are already efforts to examine animals taken by hunters (examination of the brain readily shows the presence of the disease). So I would also find out what local efforts there may be to sample deer being taken by hunters, if I were going deer hunting this fall.
Further, apparently elk and other members of the deer family are farmed (news to me). Problems here are much more approachable, since they are entirely under human control. What shooters can do there is to advocate for increased testing of these captive populations, and restrictions on their movement. For this disease, physical movement of the host is how the disease pathogen itself is able to physically distribute itself, and to gain access to other hosts (and be a bigger problem).
June 19, 2005, 06:19 PM
Smart things to do:
Keeping in mind that these diseases often have "incubation periods" lasting years, it's wise to treat any deer you shoot as if it were infected. It's also worth noting that cooking may not destroy the infectious prions so avoiding contamination during butchering is critical.
Don't eat brain or neural tissue.
Avoid damaging the brain or spinal cord of any deer you shoot. No head, neck or spine shots, and be careful during butchering to stay away from neural tissue. If brain or neural tissue is damaged, avoid any contact with it and discard any meat that comes in direct contact with the damaged tissue.
Bury or burn and bury the parts of the carcass containing the brain and spine to prevent possible spread to other animals such as predators and carrion eaters.
Apply the same precautions to any animals which may naturally prey on deer or eat deer carcasses.
June 19, 2005, 11:50 PM
Sensible suggestions, thank you.
I must admit that in the past I have been somewhat lazy with my disposal after butchering. Usually the remains get tossed into a trash bag at the shop dumptser to get tossed on the trash fire.
I'll definitely be more careful in the future.
June 20, 2005, 01:50 PM
so far CWD's posed no great threat to humans, it's not proved that it can cross, but then again no one wants to be the one to prove it. it's still obviously bad for the herd. it's a real problem east of where i hunt in WI - my family and i are parked near the minnesota border, but drive east an hour or two into the area around madison and it's a mess. they have eradication zones that i think they extended the season up until april for, just blast away, they want the deer gone. if you google it i found a reasonably good video lecture from a university on CWD that filled in a lot of the more scientific gaps for me, if i find it again i'll post the link.
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