The Real News on CWD & How Hunters Can Help
Alabama Hunting & Fishing
Over the last few years, perhaps nothing has grabbed more headlines in the white-tailed deer world than the spread of chronic wasting disease (CWD) across North America. Fortunately, CWD has not been detected in Alabama’s deer herd yet, but recent discoveries of the disease in two of our neighboring states, Mississippi and Tennessee, have caught the attention of many our residents. Unfortunately, there has been a lot of misinformation about CWD and its potential impacts on Alabama’s deer population, deer hunters, and deer hunting being distributed through various media outlets. Understanding basics of the disease and what Alabama Division of Wildlife and Freshwater Fisheries (WFF) is doing to prevent it from reaching our borders is important not only to help keep CWD out of Alabama, but also help with its management if it ever infects our deer populations.
CWD affects the central nervous system of members of the deer family, including white-tailed deer, mule deer, elk, moose, and caribou. The disease is infectious, communicable, and always fatal to these species. It is included in the group of diseases known as transmissible spongiform encephalopathies (TSEs). Other TSEs include Bovine Spongiform Encephalopathy (BSE) or Mad Cow Disease in cattle, scrapie in sheep and goats, and Cruetzfeldt-Jakob Disease (CJD) in humans.
CWD is believed to be the result of the transformation of a normal type of protein (prion) found in all deer into infectious, self-replicating, abnormal prions. Once prions become infectious, they concentrate in the brain, other tissues of the nervous system, and some lymph tissues. Eventually, the concentration of prions in the brain creates microscopic holes in the brain, leading to serious neurological problems for infected deer.
CWD has a prolonged incubation period of 12 months or more, meaning deer that appear healthy, may actually be infected with CWD. The only way CWD can be confirmed is through examination of specific tissues (e.g., medial retropharyngeal lymph nodes, obex portion of brain stem, tonsils, etc.) in a laboratory setting.
Infectious prions are found in saliva, blood, feces, and urine, with saliva having the highest concentration. Direct contact between infected deer and healthy deer is the primary route of transmission. Shedding of infectious prions from infected deer over time increases the number of CWD prions present in the environment (e.g., soil, plants, etc.). Infection from environmental contamination becomes a greater risk the longer CWD infected deer remain in an area. This makes eradication of CWD very difficult, if not impossible, in areas where CWD has been established for a long period before initial detection.
No case of human disease has been linked with CWD. However, as a precaution, the Centers for Disease Control and Prevention (CDC) recommend people eat no part of a deer diagnosed with CWD. To read more about recommendations from CDC regarding hunters and CWD, check out the following links to their website: www.cdc.gov/prions/cwd/prevention.html
CWD was first recognized as a disease syndrome in 1967 in captive mule deer at a wildlife research facility in Fort Collins, Colorado and was recognized as a TSE in 1978. CWD was diagnosed in free-ranging deer and elk in the 1980s. Since then, CWD has been diagnosed in free-ranging or captive cervids in 26 states and 3 Canadian provinces.
In areas where CWD has not been detected, such as Alabama, movement of infected, naturally dispersing, free-range animals, movement of infected captive animals, and movement of carcasses or high-risk body parts of infected animals are the most likely routes for the initial infection. Not much can be done to prevent an infected deer from travelling on its own into previously uninfected areas, but WFF does have measures in place to minimize the movement of infected deer by anthropogenic routes. Since the early 1970’s, it has been illegal to import any species of live deer into Alabama. Investigations in other states and provinces have discovered that movement of infected animals from captive facilities very likely was the reason for the disease’s spread into many previously uninfected regions. Halting the movement of live captive deer species into Alabama was and continues to be a major step in preventing the disease from reaching our state.
A more recent regulation also helps reduce the chances of introducing CWD into Alabama from outside sources. Currently, it is illegal to import whole carcasses and certain body parts of any deer species from any area outside of Alabama. Importation of the following deer parts is allowed: deer meat that has been completely deboned; cleaned skull plates with attached antlers, if no visible brain or spinal cord tissue is present; raw capes, if no visible brain or spinal cord tissue is present; upper canine teeth, if no root structure or other soft tissue is present; and finished taxidermy products or tanned hides.
On occasion, resident Alabama deer hunters that were successful in CWD positive states, had their deer tested for CWD, and brought back only the legal parts from their harvest (e.g., deboned meat, cape, etc.) may be notified that their deer tested positive for CWD after they return to Alabama. It is up to the hunters to decide if they will consume venison from CWD positive deer knowing what CDC recommends. If they choose not to eat the venison, WFF urges these hunters to contact their nearest WFF Office so arrangements can be made to properly dispose of the affected venison to minimize the potential for environmental contamination. Improper disposal runs the risk of contaminating the environment (e.g., soil, etc.) at the dump site, creating an unnecessary exposure risk for uninfected deer.
WFF also maintains an active monitoring program for CWD which began during the 2001–02 hunting season. WFF personnel collect samples from sick/symptomatic deer, road killed deer, hunter harvested deer, and animals that die in licensed game breeder facilities which are then tested for the presence of the infectious prions that cause CWD.
To better focus CWD sampling efforts for 2018–19, county-level deer harvest data from game check, density of licensed deer breeder facilities, and CWD status of adjoining states were used to rank the relative risk of CWD occurrence for each county. Counties were ranked as High, Medium, and Low Risk using the above criteria. The annual minimum statewide sampling goal for 2018-19 was 1,500 samples. The 1500 sample goal was proportionately assigned across counties based on the identified county-level risk rank. This process will be repeated each year to guide annual CWD sampling goals.
With the discovery of CWD positive deer in Pontotoc County, MS and Fayette County, TN in late 2018, portions of WFF’s CWD Strategic Surveillance and Response Plan (SSRP) were put in action. Both cases were within 50 miles of five Alabama counties (Colbert, Franklin, Lamar, Lauderdale, and Marion), and surveillance sampling of hunter harvested, road killed, and symptomatic deer were greatly increased. In Alabama’s 2018-19 hunting season, over 300 deer were sampled in those five counties.
During the 2019-20 hunting season, voluntary self-service drop-off locations will be available to improve WFF’s CWD surveillance efforts and increase access to testing for deer hunters. These locations will include chest freezers and materials (i.e., sample tags, garbage bags, etc.) for hunters to assist us with our surveillance efforts by submitting their deer heads for testing. A tear-off receipt at the bottom of the sample tag will contain an ID number that allow hunters to check the status of the samples they submit. The drop off locations will be at each WFF District Office and other convenient locations distributed throughout Alabama. Drop off locations for the 2019-20 hunting season and instructions on how to submit samples can be found at www.outdooralabama.com/chronic-wasting-disease/cwd-sampling.
Citizens of Alabama can also assist WFF with its CWD monitoring program by reporting any transport of live deer, elk, or other cervids observed on Alabama’s roads and highways by calling Operation Game Watch at 1-800-272-4263. Contacting WFF immediately makes it more likely these animals will be intercepted before they can be released.
The public is also asked to report deer showing symptoms that may indicate CWD. CWD-infected deer will show no outward or visible signs of being sick in the early stages of the disease, but as the disease progresses, CWD-infected deer will behave abnormally, showing little of their normal wariness or fear of humans. Infected animals also will become emaciated (skinny) in the latter stages of the disease. It is important to note that other diseases, including brain abscesses and chronic cases of hemorrhagic disease, may exhibit similar symptoms, but please report them regardless.
If you spot a deer that exhibits these clinical signs of CWD, report it in one of the following ways. Someone with the Division of Wildlife and Freshwater Fisheries will follow up with you.
- Call the Division of Wildlife and Freshwater Fisheries Office nearest you.
- Call the Operation Game Watch line at 1-800-272-4263.
- Report it online at www.outdooralabama.com/wildlife-related-diseases/report-sick-deer.
Cooperation and support from hunters, landowners, and others is essential to keeping CWD out of Alabama. Help keep Alabama CWD free: be informed, be vigilant, be an active participant and be responsible.