Facts about Chronic Wasting Disease and Venison Safety

Since the discovery of Chronic Wasting Disease (CWD) in Wisconsin deer this past spring, many individuals have expressed concern over the safety of venison.  The following is designed to give you some background information on CWD and to answer questions related to venison safety and handling this fall.

What is CWD? Chronic Wasting Disease or CWD is a fatal disease that attacks deer and elk. Scientists believe that CWD is caused by a protein called a prion.  Prions concentrate where there is a lot of nerve tissue, such as brain, spinal cord, eyes, and in the lymph nodes and spleen.  Prions have not been found in meat (muscle) tissue.

Why has CWD come to Wisconsin? CWD was first found in wild deer and elk in northern Colorado in the mid-1980’s.  Since then, more cases of CWD have been found in Nebraska, South Dakota, Wyoming, New Mexico, and now Wisconsin.  It is unclear what happened to bring the disease to Wisconsin, but Wisconsin’s highdeer population may be a contributing factor.  Of the deer tested in the management zone, only 3% of the animals harvested there have tested positive for the disease.  The disease appears to be ontagious in deer but, after years of research, there is no evidence that the disease can jump to humans.

Are there any precations that I should take when handling a deer this fall?  There are 2 general precautions to take when handling a deer this fall.  First, do not eat any part of a deer that appears sick.  Call the DNR if you notice a wild deer that appears emaciated or that is behaving abnormally.  Second, do not eat the eyes, brain, spinal cord, spleen, tonsils or lymph nodes on any deer.

If the deer appears helathy, is it free from CWD?  The incubation period for the disease is 18 months, with animals younger than this showing no signs of the diseease.  And even in animals older than 18 months, the animal may be infected but show no signs of the disease.  The disease is progressive, with an infected animal’s health gradually deteriorating until the animal dies from the disease.  In short, while you shouldn’t consume meat from an obviously sick animal, it is impossible to tell by looking if a deer has CWD.

Is venison from deer harvested in Wisconsin safe to consume?  Some conservative opinions advise not to comsume veison from any deer taken within the management zone in southwestern part of Wisconsin because of concerns over the safety of the meat harvested in that area.  While there appears to be less concern over the safety of venison from deer harvested outside the management zone, many consumers are still uncertain.  Public health officials note that while CWD has occurred in the US for decades, both the World Health Organization and the US Centers for Disease Control and Prevention have found no scientific evidence that CWD can infect himans.  But despite these reassureances, no one can predict with absolute certainty that CWD will never cause human disease.  Absolut safety is not attainable in mot life situations, and the current CWD situation is no exception.  Whether or not to consume venison this year is a decision that every deer hunter and his/her family will need to make.

Will Cooking destroy any prions that might be associated with the deer meat?  While taking standard precautions will reduce or elimate any contamination of deer meat with prions, cooking or canning will not destroy prions that might be present.

Can’t I hust have my meat tested to see if it is safe to consume?  The DNR has initiated a program to test roughly 50,000 deer this year for the presence of CWD.  Many deer shot in the management zone will be tested (nearly 30,000 animals) and an additional 500 deer will be tested in most of the remaining counties.  However the tests to be conducted are designed to determine the health of the animal tested.  The tests are not food safety tests; they are not designed to serve in that way.  Individuals that submit their deer for testing as part of the DNR program may wish to hold the meat until test results are available beginning in March of 2003.  However, the test results will indicate probable health of the animal only.  Ouside of the DNR testing program there are no certified private test labs available.

Are there any steps that can be taken to minimize risk?  Whether you are field dressing a deer, or processing the carcass at home, there are several steps that you can take to minimize risk

* Wear rubber or latex gloves when handling a deer carcass or venison.  This is a recommendation that we have made for several years now in light of other concerns such as E.coli O157:H7 that may affect deer and cause illness in humans.

* Do not process or consume venison from a deer that appears unhealthy in any way.

* Minimize contact with the brain, spinal cord, spleen and lymph nodes as you work, and do not consume this tissue.

* Use separate knives and utensils for field dressing a deer and for removing the meat from the carcass. Don not use household knives for field dressing.  Clean all knives and equipment of residue, and then disinfect with a 50/50 solution of household bleach and water.  Wipe down countertops and let them dry; sock knives for 1 hour.

* Remove only the meat from the deer, do not cut through any bones, and remove all fat and connective tissue before consuming or storing the meat.  One advantage of boning out the deer meat is that the boneless meat will save on freezer space and will be easier to use later on.

* Package and store the meat from each deer separately.  Be sure to label each package.

* Do not cut through the spinal column except to remove the head. Use a knife or saw for that purpose only, and dispose of the blade.

* Dispose of the brain, spinal cord, eyes, spleen, tonsils, bones and head in a landfill or by other means available in your area.  Contact the DNR if you are unsure what options are available to you.

What if I normally take my deer to a meat processor?  Contact your meat processor prior to hunting, to find out if they will be taking deer for processing this year.  And be sure to ask if they have any special procedures or policies that you may need to know about this year.

Can I still donate my meat to the local food pantry?  Food pantries in some parts of the state are participating in venison donation programs this year.  Deer that are donated are dropped off at participating state or federally inspected meat plants where they will be processed into meat for donation to local food pantries.  Pantries will not accept venison that was processed at home.  Contact your local food pantry prior to hunting to find out whether you can donate your deer to feed the hungry.

What about making soup stock from the bones or tannin the deer hide?  Until we know more, UW-Extension recommends that you not stew deer bones for soup stock.  There are no apparent concerns over CWD and deer hides, and hide processors in the state appear to want deer hides this year.

We will continue to learn more about CWD and its impact on the Wisconsin deer herd over the next several months.  If you have questions or concerns related to venison handling, processing, or consumption, please contact your local county extension office.

Prepared by Barbara Ingham, Extension Food Scientist, 2002