‘CWD is in the local deer population in Rappahannock County’
Whatever your interest in or aversion to white-tailed deer, you may eventually see fewer of them sprinting across the road, eating your cabbage or magnified in your rifle scope. The reason: chronic wasting disease, a fatal, incurable affliction that continues to spread in the mid-Atlantic.
Hunters and wildlife managers in the region can do little but slow the spread, hoping to head off the kind of scenario that has devastated deer populations in a few other states.
CWD was first detected in North America in a mule deer at a government research facility in Colorado in 1967. Since then, it has spread to 26 states. Though the number of deer found with CWD in the mid-Atlantic is relatively low so far — a total of 1,309 in Pennsylvania, Maryland, Virginia and West Virginia — the disease is expanding into new areas of each state.
The first case of CWD in Virginia was identified in Frederick County in 2009. Diseased deer have been reported in seven new counties over the last two years, including Rappahannock, where one positive deer was detected in 2020. According to the Virginia Department of Wildlife Resources, over 27,000 deer have been tested for the disease since 2002.
“It’s important to remember that one single positive deer means that we tested one positive deer. It doesn’t mean that there aren’t other positive deer on the landscape,” said Megan Kirchgessner, state wildlife veterinarian with the Virginia Department of Wildlife Resources (VDWR).
Since its first detection in Virginia in 2009, 109 cases of CWD have been identified in Virginia across nine counties. Shenandoah National Park has not yet detected any CWD deer within its borders, but it has a response plan in place for when the time comes. “What I’ve been told is the closest it’s been is 11 miles from the park boundary,” said Patrick Kenney, park superintendent. “It’s concerning.”
Kenney said that the park is currently conducting opportunistic surveillance of deer, meaning any time that a car hits a deer or a deer is killed, park officials collect tissue samples and test them for CWD.
With no cure and no vaccine, all wildlife managers can do to control the spread is dramatically reduce the size of deer herds. The Shenandoah National Park’s 44-page response plan, first drafted in 2014, calls for reducing population density through lethal removal by authorized agents.
In other areas, herd reduction is being accomplished mainly by increasing bag limits for hunters in affected areas. But that approach is hampered by the fact that not all hunters believe that the wholesale killing of deer is a solution.
A 2018 report by Gray Anderson, chief of wildlife at VDWR, reached a sobering conclusion: “Based on what we know right now, CWD is among the greatest threats to the long-term health and stability of our deer herd. … CWD is essentially impossible to eradicate and very difficult to manage or contain.”
No humans or livestock have gotten sick from eating or coming in contact with infected deer, but public health officials worry it could happen. “Chronic wasting disease has not been proven to be able to jump the species barrier and infect humans at the moment,” said Kirchgessner at the VWDR. “However, there are related diseases that are similar to CWD that we know can affect humans, like mad cow disease. Mad cow is basically the cow version of CWD.”
For that reason, the U.S. Centers for Disease Control and Prevention strongly warns hunters not to consume diseased animals.
What causes the disease?
CWD is thought to be caused by malformed or “folded” proteins, called prions, produced in the bodies of white-tailed deer and other cervids such as mule deer, moose, elk and caribou. These aberrant proteins pass on the malformation to normal proteins, spreading the condition through the brain. The accumulating folded proteins riddle the brain tissue with tiny holes, rendering it sponge-like and increasingly dysfunctional. As the brain impairment progresses, it causes health effects such as emaciation, but also significant behavioral changes — and, invariably, death.
According to the VDWR, prions “are found in saliva, urine, feces, and blood … [and] can persist for years in soil and in other substances, can be taken up by grass roots from contaminated soil, and can be transmitted by infected cervids that are not yet showing symptoms of the disease. Even very small doses of the infectious prions can cause CWD to develop.”
There is no sign that deer are building up a resistance to the disease, and it is very difficult to detect CWD in living deer. “The most reliable samples on the deer that are the most likely to be positive if that deer actually is infected are really not appropriate samples to take from a live animal,” Kirchgessner said. “Those samples are actually the lymph nodes that are located behind the voicebox, and that’s not something you can go in to remove on a live animal.”
Male deer are the most susceptible to getting CWD because they tend to travel the farthest and their social behavior brings them into contact with more deer. Culling male deer, therefore, is believed to be more effective in reducing transmission.
The VDWR began cooperating with taxidermists in 2018 to test older male deer for CWD. During the 2020-21 hunting season, taxidermists throughout the state submitted more than 2,500 samples to VDWR for testing.
Help needed from hunters
How bad could it get? Wisconsin was the first state east of the Mississippi to have CWD, beginning in 2002. Despite culling efforts, the disease is now in 32 of 72 counties and hunters that venture out in CWD hotspots have a nearly 50 percent chance of shooting an infected deer.
In Colorado and Wyoming, an estimated 40 percent or more of free-ranging cervids in certain hotspots contract the disease and die from it.
Cooperation from hunters will be essential for CWD to be constrained, wildlife managers say.
In Rappahannock and surrounding areas, hunters are asked to bring harvested deer heads to one of several drop sites for voluntary testing. The CDC recommends that all deer harvested in an area with known CWD be tested.
Despite gloomy trends, game officials hold out hope that CWD can be minimized, if not eliminated.
The Virginia Department of Wildlife Resources will hold a public meeting for hunters and concerned citizens addressing the issue of CWD in our area. Stay tuned for details.
To report a sick deer to the VDWR, call the Wildlife Conflict Line at 1-855-571-9003. Sick deer may show neurologic signs (loss of coordination, droopy head or ears, lack of fear of humans, excessive drooling, etc.) and extreme emaciation. Accurately document the location of the animal. Do not contact, disturb, kill, or remove the animal without permission from the department.
Ad Crable is a Bay Journal staff writer based in Pennsylvania. This article was originally written for the June 2021 Bay Journal and was distributed by the Bay Journal News Service. The Rappahannock News contributed to and edited the article.