Featured Blogs

CWD Monitoring: A Proactive Approach

Author: NCWRC blogger/Tuesday, October 19, 2021/Categories: Blog, Conservation, Hunting

CWD Monitoring: A Proactive Approach

by Sydney Brown, Education Specialist, Wildlife Education Division

Chronic Wasting Disease (CWD) weighs heavily on the minds of biologists across the United States as a silent killer of deer and elk. With a recent positive case just over 30 miles across the state line in Virginia, N.C. Wildlife Resources Commission (NCWRC) staff are hard at work increasing CWD monitoring efforts this deer season. A special session June commission meeting resulted in discussions and presentations from surrounding states with positive CWD deer herds and shed light on different situations should a CWD positive deer or elk surface in North Carolina.

The concern about CWD is largely because it is a pervasive Transmissible Spongiform Encephalopathy (TSE), more commonly known as a prion disease, which is caused by an abnormally folded protein (known as a prion) that is extremely persistent in the environment. As there is currently no cure, each positive CWD case will result in a fatality which makes CWD one of the greatest threats to the North American members of the deer family Cervidae, which includes various species of deer, elk, moose, and reindeer/caribou.

Due to CWD’s long incubation period, it is difficult to tell if an animal is suffering from CWD until the disease has run its course. Weight loss, listlessness and lack of coordination, drooling, drinking copious amounts of water and increased urination are all signs to look out for. However, CWD prions have been detected in the urine, feces, blood, and saliva of infected deer well before the animals begin to exhibit any obvious signs of the disease. Infected white-tailed deer take at least 16 months to show symptoms, which means the disease can circulate through the deer herd undetected until it is too late.

CWD has not yet been detected in North Carolina’s deer herd, but since first being identified in the late 1960’s in a Colorado research facility, the disease has spread to at least 25 states. The NCWRC has conducted CWD testing in North Carolina since 1999 and in 2018 a revised surveillance strategy was adopted with sampling occurring on an annual basis with five-year sampling goals for each  county in the state. Since annual sampling began in 2018, the NCWRC has tested roughly 2,000 deer per year. In total, more than 15,000 deer have been tested since 1999. Sampling and testing for CWD is imperative because most deer population models predict notable declines or even localized extinctions over a period of 50 to 200 years following the first positive case.

There is currently no scientific evidence that CWD can infect humans and there have been no reported CWD cases in people, but the potential impacts of CWD on human health remain largely unknown. The Centers for Disease Control stresses the importance of keeping the agents of all known prion diseases from entering the human food chain. The NCWRC recommends that hunters take precautions when handling and processing deer. Safeguards include wearing rubber or latex gloves, using knives or utensils only for field dressing and processing, and minimizing contact with the brain, spinal cord, spleen and lymph nodes during deer processing.

NCWRC biologists state that once a positive case is identified, North Carolina must act decisively to stop the bleeding. The bleeding being the unchecked spread of prions throughout the environment. Catching CWD early, when the bleeding is just a trickle, is difficult, but with the correct management strategies the hope is to maintain CWD transmission rates at low levels and contain it to the greatest extent possible. This goes alongside the understanding that the NCWRC is still dealing with a free-ranging deer herd.

In September 2021, the NCWRC CWD Response Plan presented at the special June meeting was revised and approved. Notable response measures include:

  • Novel disposal methods of deer carcasses and carcass parts.
  • Prohibition of the intentional feeding of deer.
  • Obtaining tissue samples from over 50 percent of the estimated animal population in an area within a 5-mile radius of the original positive location.

With hunter cooperation and NCWRC staff continuing to survey for CWD, as well as the North Carolina Department of Agriculture and Consumer Services, the NCWRC is ready should a positive CWD sample surface within the state.

If you would like to read more about CWD, please visit ncwildlife.org/CWD.

 Find this article and more at ncwildlife.org/WINC.

Photo credit: Shutterstock, Bruce MacQueen

 

Print

Number of views (228)/Comments (0)

Please login or register to post comments.