Chronic Wasting Disease (CWD) in Deer
Deer mating season (rutting has started), so deer are on the move. Hunters need to be aware of Chronic Wasting Disease (CWD); a fatal, infectious disease affecting the nervous system of deer. It is caused by misfolded proteins called prions. It spreads through direct animal contact, contaminated environments, and bodily fluids, and animals can shed prions for years before showing symptoms like weight loss, poor coordination, and drooping ears. The Ohio Department of Natural Resources (ODNR) recommends not consuming meat from CWD-positive animals and taking precautions like wearing gloves and avoiding brain tissue when handling deer carcasses.
CWD has been found in Northwest Ohio. Major hot spot are Wyandot, Marion, and Hardin Counties but many surrounding counties are also affected with confirmed cases in Allen and Morrow Counties. Not all deer are tested, so since the deer population is mobile and far ranging, it could easily be spreading.
CWD is very similar to other prion diseases that affect the brain including “mad cow disease”, Creutzfeldt-Jakob disease, and scrapies in sheep; with symptoms resembling Alzheimer’s disease. The big issue is that recently some macaque monkeys were fed meat from CWD-infected white-tailed deer that didn’t look sick. The monkey’s got sick from prions in the deer’s red meat. Most research scientist recommend that no one eat the meat of any prion-infected deer. However, there is more research which says something else.
CWD most resembles scrapie of sheep. The scrapie disease has been around for hundreds thousands of years; so, millions of people have been exposed to scrapie with no evidence of transmission. Some research shows that CWD prions are simply in the wrong shape to interact with human prions. There is research on both sides of CWD infected meat.
There may be a CWD’s species barrier. Amino acid sequence differed between humans and deer at a key location. A different study showed that the macaque monkey amino acids matched the deer sequence in the same spot, but not the human one. Thus, the CWD species barrier may help keep humans safe. The key word is “MAY?” However, so far, no one had died from CWD. Therein lies the controversy with CWD.
Jeff Sindelar, an associate professor of meat science at the University of Wisconsin-Madison, says these are socially-based concerns, not concerns based on science. “There has never been a link between eating venison and CWD,” he says. “The risk is not zero, but it’s pretty close to zero.” Unfortunately, it is not a total black and white issue. CWD is a brain disease caused by prions (unfolded proteins) that damage the brain and nervous system. Prions may persist many years and are shed in saliva, urine, and feces. Deer, elk, moose, reindeer are affected. The disease spreads through direct contact between animals and indirectly through contaminated carcasses.
CWD Symptoms and signs include odd behavior and reduced fear of humans. Infected animals have drastic weight loss, drooping head and ears, glassy eyes, drooling and poor coordination. Animals close to death seem in a daze, may have a high fever, and often search out water. One farmer said he saw a deer in a corner of a corn field which he passed 3X as he was hauling corn. He got out of the truck, approached the animal and even petted it (not a good idea.) It later disappeared. Another farmer said he found five dead deer near his pond. Some deer may be infected with the CWD disease for years and not die immediately from it. Here are some general recommendations. Avoid supplemental feeding sites because both healthy and sick diseased animals congregate at these locations which makes the spreading of the disease more prevalent. Wear gloves when processing deer. Avoid handling the brain or nervous system (spinal cord) of all deer harvested. Avoid deer with flaky or misshapen hooves. Dispose of deer carcasses following all state and local guidelines. Go to the ODNR-ADDL website for details. ODNR suggests avoiding urine-based lures because they can contain prions and persist for many years in the environment. Avoid transferring deer meat over state lines which may spread CWD. Cook all deer meat to at least 165°F. Prions cannot not be killed by boiling or exposure to acids, radiation, or antibiotics. Wash hands and tools thoroughly with soap and water after handling deer carcass.
It is recommended that CWD infested meat not be eaten. To test for CWD, visit the ODNR animal disease diagnostic lab web site. The CWD process for testing involves submitting a sample from a fresh deer head at a cost of $83 per sample. Follow all directions. Contact the ADDL for testing at 614-728-6220 or email submissions@agri.ohio.gov.
