An Introduction to Chronic Wasting Disease in Deer
Dr. John Woods 04.14.18
The cervid animal disease called CWD or Chronic Wasting Disease has infected wild game animals in some 23 states now. The State of Mississippi just joined the list with the discovery of a dead deer in late January that was tested positive for CWD in a lab procedure in Iowa this February. Only the other 22 states know the shock of such a discovery.
Mississippi deer hunters, land owners and wildlife managers are just in the infant stages of coming to terms with the initial evidence of a first deer testing positive for CWD. The panic has already set it. Some of it is warranted and some has been blown out of proportion. The expectation is that many more questions will come before the answers. The waiting game is always the most difficult phase.
In Mississippi’s case the state wildlife agency, the Department of Wildlife, Fisheries and Parks has reacted quickly to this discovery. Frankly they had been planning well ahead for this eventuality. They have already issued their 33-page CWD Response Plan. First, a six county area around the discovery zone in Issaquena County along the Mississippi River has been established. An executive order was issued to stop all supplemental feeding of deer as a measure to curtail spread of the disease. People have been advised as a precaution not to eat deer meat from this impacted area.
An extensive deer sampling program in this six county area is to begin soon. This is an attempt to see if there is any statistically significant finding that more deer have also contracted the disease. These are standard protocol measures to initiate a CWD management plan for the state. Much more information will be forthcoming including planned community meetings as necessary once more is known from the sampling and testing.
The citizen’s panic is already growing. Deer meat processors are getting calls from customers saying they are not going to pick up their deer. These business people are wondering if they will be paid for the processing and then, what to do with the tons of processed meat. Local radio and TV have blitzed the issue over and over trying to make people aware with an attempt to answer questions. Wildlife officials have been guests on these shows to disseminate information and field questions. More of that will be coming in the months ahead.
Meantime, it occurs to many that most people and particularly deer hunters, and deer managers know very little about the specifics of the disease. We suspect this is the case in many of the other impacted states as well. In order to provide basic information about issues dealing with CWD, one knowledgeable person was contacted for his input on the situation.
Co-author to this piece, Ron Eller, is owner of Buck Warrior Enterprises in Mississippi. Ron’s company produces a number of deer hunting enhancement products, so he is naturally interested in how CWD might impact his business. Aside to that, Ron is also a highly trained medical professional serving in a cardiac unit at a local hospital. He understands physiology, diseases, chemistry, and related issues. Here is his explanation of CWD in a layman’s terms:
“With the Chronic Wasting Disease, (CWD) outbreak in white-tailed deer there are many theories on the how’s and whys of this disease. CWD was first discovered in 1967. It was isolated in captive mule deer in Colorado. Since then CWD has been found in both free range cervids as well as captive (pen) animals. It is believed that CWD affects only cervids (hoofed animals in the cervidae family such as deer, elk, and moose).”
“CWD affects the deer’s nervous system (brain and spinal cord). Once it is established in the host animal’s body, prions transform normal cellular protein into an abnormal shape that accumulates until the cell ceases to function. There is also a human disease variant called Creutzfeldt-Jakob Disease (CJD). It is a rare, degenerative, invariably fatal brain disorder.”
“I think in order to understand the basis of CWD, we must first look at Mad Cow Disease (Bovine Spongiform Encephalopathy {BSE}). When BSE first appeared on the scene there were many theories on how it was transferred from one animal to the next, and whether it could be spread to other species including humans.”
“In the end after countless hours of research there came two conclusions that have born weight and have stood the test of time. First that BSE can be spread from one animal to another or other species. The route of transmission from one animal to another is by eating or handling contaminated nerve tissue (brain or spine). The second means of transmission was from feed that was made using a combination of animal feces mixed with grains and supplements. The use of fecal matter was thought to cut cost and still provide some nutritional benefits. The animal feces in this mixture was not completely digested. The theories of BSE being spread by congregating animals, and saliva did not hold true.”
“Now how does this relate to CWD? BSE and CWD are very similar in the effect on the host animal, with the end result being death. At this time there is no clear cut determination on how CWD is spread. It is my hypothesis after many hours of observation and tons of feeding deer in both pen and free range situations that CWD is the deer equivalent of BSE. And like BSE and Hepatitis A, I believe in time that it will be found that CWD is most likely spread via the fecal oral route.”
“If this theory holds true then congregating deer is not the problem. Nor is feeding or supplementing deer the problem. But, rather the method of how said feeds, supplements, and attractants are offered. Hence in order to break the fecal oral connection it is a matter of elevating the feed from off the ground and offering it on logs, stumps, or in troughs. When deer are allowed to congregate and eat from the dirt, this act increases the risk of disease transmission.”
“By my observation deer like many animals will use the bathroom and relieve themselves evacuating both bowel and/or bladder in these feeding areas contaminating the soil. Hence, this waste is accumulating in the soil and then being consumed by the next animal to eat there. There is also concern that it could be spread via deer urine attractants. In theory that sounds and seems plausible, however given the small amounts of animal waste in a couple ounce bottles of deer urine and the sparing use that most hunters apply deer urine in a hunting situation, I feel this is highly unlikely to be the cause.”
“As for CWD being spread from saliva, my observation of both deer in the wild and in pen situations, I think this is highly unlikely as well. I have seen firsthand and in photos, deer nose to nose and licking each other’s faces without ill effects. Deer have exhibited that behavior since the dawn of time and will continue to do this no matter what we do.”
“There are a lot of concerns and questions on the safety of consuming deer meat. That is an individual question that you must ask yourself. To help make this call ask yourself was the animal healthy? Did it have signs and symptoms of CWD? What were those signs?”
“The signs and symptoms of CWD: animals that are infected begin to lose weight, lose their appetite, and develop an insatiable thirst. They tend to stay away from herds, walk in patterns, carry their head low, salivate, and grind their teeth. The one piece of advice that I would give on eating deer meat is not to eat any organs, (liver, heart, brain, etc…) or use intestines as casing for sausage. Second, eat well cooked food with a temperature of at least 150 degrees Fahrenheit with steaks, roasts, and ground meat at 160 degrees Fahrenheit,” states Ron Eller.
Very often, a discussion of CWD brings more questions. At lot is known, a lot is not. If you hunt where CWD has been declared, then follow the laws, rules, regulations, and advice of your state’s wildlife agency. As in Mississippi, they are the experts and we have to trust them until we know otherwise.
