Chronic Wasting Disease: The Missouri Front
September 30, 2010
No, it's not in the Show Me State &151; and with luck it'll never get here. Read on for the what, where and how of CWD.
By Doug Smith
It's a problem that up until recently never even raised a concern with deer hunters in Missouri. The problem of possibly killing an animal infected with chronic wasting disease wasn't a worry - primarily because most hunters didn't even know that CWD existed, much less what it was.
Well, all that's changed in the past five years. The degenerative brain disease found in mule deer, white-tailed deer and elk is slowly making its way to Missouri. It's a matter not of whether it'll appear in the Show Me State - it almost certainly will - but rather of when, and of what can be done to contain and control its spread.
In this article, we'll take a look at what CWD is, why it's got hunters and conservation specialists alike concerned in our state, what we as Missouri hunters can do to help keep a watch out for it and what health specialists say about risks associated with eating meat from infected animals.
BIOLOGICALLY SPEAKING CWD is a "TSE" - one of a group of communicable disorders known as "transmissible spongiform encephalopathies." Put simply, they riddle an infected brain with holes so that it resembles a sponge. First detected in the United States in 1967 in a deer in northeast Colorado, the disease has slowly and systematically spread across western states and moved eastward. Not too long after CWD was found in a wild deer, it was also discovered in a small elk population.
The good news about the issue, and there is some good news, is that as far as medical experts can tell, CWD is in no way a human health concern. To date, of all the cases investigated in both free-roaming and penned animals there has never been a medical problem in a human associated with eating meat from animals near those affected. So what's the big deal - right?
The big concern is that while CWD may not be transmittable to humans, any transmission in the whitetail population of the state could have a detrimental effect not only the deer population, but on the generous revenues generated through Missouri whitetail hunting (i.e., licenses, permits, processing fees, hunting and camping supplies, promotional sources, etc.). Discovery of one infected animal in the state would do little to discourage whitetail hunting as a sport, but an infestation of the disease could drive away a major portion of the revenues generated each year from our only naturally-occurring big-game animal. Yet another concern is the possibility of CWD infiltrating hunting farms and quickly knocking private profits in the head.
Though fatal to deer and elk, CWD is not communicable to humans. You should still take basic precautions. Photo courtesy of Scott Tincher
WHERE IT IS - OR IS IT? Before taking a look at where CWD has been discovered, let's look at what the Missouri Department of Conservation is doing to locate any potential cases inside state lines.
If you hunted this past fall in one of 30 counties targeted by a new MDC study, it's likely you were asked to donate the head of your kill for testing. Some 200 hunters in each county were asked to give up the head of their animals to be removed and eventually taken to an MDC location where the brainstems were stripped, documented and packaged for transport to one of two labs for testing.
In 2001, the MDC only tested 72 deer for CWD. This past year, 6,000 samples were collected. A different 30 counties will be targeted this fall, and then the remaining 54 counties will be sampled and tested in 2004. Counties providing samples in 2002 included Andrew, Bates, Bollinger, Caldwell, Callaway, Carroll, Chariton, Christian, Clark, Clay, Clinton, St. Francois, Franklin, Greene, Holt, Jasper, Jefferson, Johnson, Madison, Monroe, Pike, Platte, Ripley, St. Clair, St. Louis, Scotland, Sullivan, Taney, Texas and Warren.
Lonnie Hansen serves as the MDC's leading authority on white-tailed deer. It's the job of Hansen and his colleagues, working from an office in Columbia, to try to monitor and improve Missouri's deer herd. It's a job that the group and the MDC have done well in recent decades. The number of deer, and especially good-sized bucks, are at a premium in many areas of the state. Even counties lagging behind are showing improvements in deer populations through good land management and enforcement practices. It's a trend that Hansen doesn't want to see reversed because of a rampant but undetected influx of CWD. Hence the detailed three-year sampling.
By the time you read this, the MDC will have learned the results of the first 6,000 deer brainstems tested. The testing was done at both the University of Wyoming and at the Southeast Cooperative Wildlife Disease Study, based in Georgia. It was hoped the state would have some answer on the first shipments tested by early March, but because of increased caseloads from similar testing in other states, it was to be summer before a "yes" or "no" answer could be given.
"We told them we didn't want to know any of the results until all the samples had been tested," Hansen said in early March. His reasoning was that the discovery and disclosure of one positive sample announced early in the testing could start a scare that might be unfounded if there was only one positive test in the entire group of 6,000 brainstems.
Again, Hansen is quick to remind us that, as no epidemiological link between humans and CWD has been established, any discovery of a positive case in the state would be more of a management concern than a medical one.
Which raises the question of just where CWD has been found to date. Hansen says that as far as wild populations of animals are concerned, the closest to Missouri would be western Nebraska, northern Illinois, or southern Wisconsin. There has been a documented case in Kansas, but that was apparently in a fenced-in animal. Other states having documented cases include Colorado (where the first discovery was made in 1967), Minnesota, Montana, New Mexico, Oklahoma, South Dakota, Wyoming and Saskatchewan and Alberta in Canada.
STOPPING CWD IN ITS TRACKS A deer or elk infected with CWD might exhibit tremors, stumbling, having excess saliva, loss of appetite and weight loss and other changes in natural and normal behavior. With no known cure at this time, it's believed that CWD is always ultimately fatal, but the life expectancy in an affected animal in not known. Studies have shown animals can have the fatal disease and still live months or years before showing visible signs of illness. Hence the recent change in the state's attitude toward testing seemingly healthy animals, as opposed to testing only animals reported to have a problem or being suspect.
To date, the only sure way of spotting CWD in a suspected animal is to physically examine the brain stem. That's why scientists are working on a method to test live animals, but for now must resort to destroying and decapitating the animals to study them. Late last year, following fall firearms deer season, the MDC assembled a group of workers and gave a crash course in correct procedures for removing brainstems. This group then went to work on the 6,000 deer heads collected weeks earlier.
Now that the state is getting a handle on the testing for CWD, thoughts must also turn to enforcement and keeping infected animals, both live or pre-harvested, out of Missouri's populations of both wild and confined deer and confined elk.
Perhaps the natural movement of the disease into the state may be slowed by the sparse number of cases discovered to date in our neighboring states. A major concern, though, is the accidental "shipping-in" of the disease through the interstate transport of animals. Buying and selling of deer and elk in Missouri for personal or paid hunting preserves, or "farms," is a burgeoning industry, and keeping a close eye on just what animals are allowed to cross state lines is a growing problem. Since testing isn't possible in live animals as of yet, documenting and tracking the origin of an animal and the known health of the herd from which it came seems to be the best bet so far. Boiled down, the burden of proof and compliance seems to rest on the individual animal buyer and owner - the other side being that no one wants to be the first person in the state to bring in an infected animal.
Just how CWD spreads from animal to animal is still unknown. Logic would say that spreading could likely occur through interaction at feeding and watering locations.
In an effort to put together every bit of information and monitoring capability available, the Missouri Department of Agriculture has established a CWD Task Force made up of representatives from the MDC, other conservation-minded groups, state and federal agencies, meat processors who handle wild game, state universities, members of the state legislature and groups representing captive animal ranchers or managers.
The actions of the agriculture department to form and oversee the task force was an admirable effort in light of the fact that to date there has been no linking of CWD to domestic livestock of any type. Should CWD be discovered in deer or elk in Missouri, a contingency plan already in place would be implemented to govern actions until a more detailed management plan could be formulated.
THE HUMAN SCARE So should hunters be afraid to harvest and eat meat taken from a whitetail deer or elk killed in Missouri, or any other state for that matter? While it may be that no one wants to be the final authority to say "no," several popular and well-known outdoor figures have come out in recent years with messages indicating that they fully intend to continue hunting and harvesting deer and elk despite the discovery of CWD. Common sense warrants that any suspect animal should not only be avoided for consumption, but reported to the authorities, as well. That aside, there's no proof for the position that a healthy-seeming deer or elk should not be harvested and enjoyed just as they have been for centuries. To back this up, the Missouri Department of Health and Senior Services (the state's premier public health authority) says there's no evidence that CWD can "infect" humans. That claim is supported up by both federal agencies and state agencies from other states. Should a link between CWD and humans be found, a food warning would surely be issued immediately.
Admittedly, the amount of information available through the MDC regarding CWD is limited. After all, the disease has been of little more than a passing concern until recent years. Still the MDC posts a detailed question and answer explanation of CWD facts on its Web site. It goes further by showing a map outlining the states and counties in those states with confirmed cases of CWD in animal herds. MDC officials have said they will be open and honest about all findings from the current random sampling of harvested deer. In fact, hunters donating heads to the test have been invited to contact the MDC after the results are released in order to check specifics regarding a particular animal or county should there be positives in the findings.
WHAT CAN I DO? The average hunter should take general precautions while field-dressing or processing deer or elk. Wear rubber gloves, which you should be doing already. Not only will the gloves help protect any spreading of disease agents within the meat, but they'll help prevent the careless introduction of contaminants from outside sources by handling.
The next thing is for landowners or private herd owners to closely watch and manage deer or elk herds. Help in learning how to successfully manage a population of animals is available through the MDC or Department of Agriculture Division of Animal Health based in Jefferson City. The number for MDA is (573) 751-3377. The MDC's research center, which houses the offices of Hansen and other state deer experts, can be reached by calling (573) 882-9880.
Experts like Hansen admit that the concern over CWD in Missouri is real, but temper that concern with the fact that their watchfulness is geared toward isolating any cases in the state before they can spread and infect a large deer population. As noted, an infiltration of the disease in the state's free-roaming deer or privately-owned elk or deer herds could have long-term economical and biological impacts.
"We have tried to take a calm, rational and responsible approach to this," Missouri Conservation Commission chairman Howard Wood said recently. "We recognize that this disease poses a threat to Missouri's wildlife, its agriculture and its economy. But acting out of fear, before we thought through all the effects of our action, could have had tremendous negative effects, too." Wood was speaking of changes in the state conservation commission's methods of handling the increasing threat of CWD in the state, including the decision to start the three-year hunter participation study of brainstems from harvested deer.
So you see, there are two aspects to the watch for CWD. The first is the MDC's concern for free-ranging white-tailed deer. The second is the importation and exportation of deer and elk for profit among breeders, ranchers and preserve owners and operators. The MDC retains authority, or at least regulatory authority, as far as wild deer and captive deer and elk at hunting preserves are concerned. The state's agriculture department will continue to regulate "farmed elk." Everyone involved seem to agree the agriculture department is a leading voice in the fight against CWD, much as they were against previous battles to control brucellosis and tuberculosis in animal herds.
"The path we have chosen keeps the two state agencies that are responsible for tackling this issue working together with the captive deer and elk industry to protect Missouri from chronic wasting disease. Our new regulations mesh with those that the Department of Agriculture is developing to provide a reasonable level of protection. ... No workable solution is possible without the expertise of both o
ur agencies and the cooperation of all the people with a stake in this issue," Wood added in an MDC press release.
So while the MDC agents weren't at the check station when I rolled in with my deer in 2002, I would have gladly donated the head for testing if asked. As an outdoor writer, part of my future income rides on a healthy and flourishing deer population in Missouri. And don't think this could only affect me, either. The guy at the local gun shop, my buddy in the sporting goods department, another buddy who has a small but growing elk herd, and the state conservation department that sells the tags and keeps things rolling with the deer we all like to hunt - all of us have a stake in doing our part to be informed, watchful and cooperative when it comes to those three little letters: "CWD."
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