Chronic Wasting Disease
Rhode Island Hunting
Chronic Wasting Disease (CWD)
By Sarah Riley, Implementation Aide, RIDEM
Chronic Wasting Disease (CWD) is a fatal, neurodegenerative disease affecting populations of both captive and wild cervids across North America.
This disease is caused by infectious proteins known as ‘prions’, which can be transferred between individual animals through bodily secretions, such as saliva and urine, and has shown extreme resilience once established in the environment. The most susceptible species are cervids such as elk, moose and deer, including white-tailed deer (Odocoileus virginianus). Although there is no evidence that CWD is transmissible to humans, it is highly contagious between individual animals and its proliferation has proven difficult to control. CWD continues to spread to new locations every year, and the rate of human interaction with infected cervid populations seems to be on the rise. Some researchers anticipate potentially catastrophic impacts to cervid populations across North America, which could greatly impact ecosystems and decimate economies. For these reasons, CWD has become a major concern for wildlife managers, hunters, and conservationists across the United States, as well as around the world.
The prion which causes CWD is similar those which cause Bovine Spongiform Encephalopathy (‘mad cow disease’), a disease known as ‘Scrapie’ which effects goats and sheep, and Creutzfeldt-Jakob disease in humans. Some scientists believe that CWD may have actually developed from the prion which causes Scrapie, although the true origin of this disease may never be known.
These infectious proteins are taken up by the host animal by feeding in an infected area or by coming in contact with urine or saliva which contains the prion. The prion then spreads through the nervous system – by means of a chain reaction – in which particular proteins in the host animal’s body are misfolded into the shape of the prion itself. This causes lesions throughout the nervous system, particularly in the brain, resulting in significant behavioral changes in the animals and ultimately, their death. The term “chronic wasting” refers to the disease’s most characteristic symptom: the inhibition of the host’s natural feeding behavior and eventual starvation. The infected animal may also drink excessive amounts of water and thus may be seen standing in or near bodies of water. They can appear lethargic, with their legs spread in a wide stance, drooling or hanging their head low. As with all prion diseases, there is no known cure and once clinical signs are evident, the animals invariably succumb to the disease. Efforts continue to investigate the mechanisms of infection and transmission, but for now, implementing known methods of control can help slow the spread of CWD.
To date, CWD has not been found in Rhode Island, or anywhere in New England. However, since its confirmation as a prion disease in Colorado in 1967, it has since spread to 24 states, 3 Canadian provinces, and as of this year, to Europe; New York is the closest location to Rhode Island where CWD has been found. Researchers believe that this is due, in large part, to the greater susceptibility of captive deer herds to communicable diseases which results from their higher population densities. These infections can then be spread to wild populations when wild herds interact with infected captive herds or encounter infected bodily fluids, such as urine. Research indicates that CWD spread to new locations due to the use of natural urine lures.
For over ten years, the RIDEM Division of Fish and Wildlife has been conducting surveillance for CWD by collecting lymph node tissue samples from harvested deer. During the first four days of the muzzleloader season (November 4 – 7, 2017), deer hunters can participate in this research by allowing state biologists to collect the necessary tissue from their harvested deer. Those samples are then sent to a lab for testing. The prolific and resilient nature of CWD warrants continuous monitoring by Rhode Island’s hunters and wildlife managers to ensure a healthy, sustainable deer population. Regulations have been established to prevent the spread of CWD, and further guidelines can be followed to better ensure that Rhode Island remains CWD-free. Below are some of these state regulations, but it is not a complete list. For more information, see the Rules and Regulations Governing the Importation, Feeding, and Baiting of Cervids in Rhode Island.
- No person shall import into Rhode Island or possess in Rhode Island the carcasses or parts of wild cervids taken in or originating from a Chronic Wasting Disease endemic area, or carcasses or parts of captive or captive-bred cervids from outside Rhode Island. Except that the following parts may be imported or possessed if marked in the manner described in § 2.15 of the Rhode Island Rules and Regulations Governing the Importation, Feeding, and Baiting of Cervids in Rhode Island:
- Meat may be imported and possessed provided that all such meat from an individual animal shall be boned, cut up, packaged and wrapped, and such meat shall not be commingled with the meat of any other;
- The hide or cape;
- The skull-cap with antlers attached, free of blood and brain matter;
- The antlers;
- Finished taxidermy;
- Tanned hides;
- The upper canine;
- Fresh head and cape – in addition to the marking requirements of § 2.15(A) of this Part, the required tissue must be tested by a certified USDA laboratory and must be certified to be Chronic Wasting Disease free. This certification must be in writing and must be provided prior to importation of a fresh head and cape into the state of Rhode Island.
- No person shall feed cervids at any time in the state of Rhode Island except:
- Under a license or permit issued by the Department pursuant to R.I. Gen. Laws § 20-1-18 for bona fide scientific research;
- By planting, cultivating, or harvesting of crops directly associated with bona fide agricultural practices, including planted wildlife food plots;
- By distribution of food material for livestock directly associated with bona fide agricultural practices; by distribution of food material for legally possessed captive cervid, pursuant to a permit;
- By cutting of trees or brush;
- Elevated bird/squirrel feeders providing seed, grain, fruit, worms, or suet for birds or squirrels located within 100 feet of an occupied dwelling.
- No person shall import or possess in Rhode Island the brain, eyes, spinal cord, lymph nodes, tonsils, or spleen of any cervid taken in or originating from a Chronic Wasting Disease endemic area, or such parts from captive or captive bred cervid obtained from outside Rhode Island, except as pertains to Rules and Regulations Governing the Importation, Feeding, and Baiting of Cervids in Rhode Island.
- Carcasses and parts of any cervid imported into Rhode Island, or packages or containers containing such carcasses or parts, shall be affixed with a legible label bearing the following information: the species of animal, the state, province or country where the animal was taken or where the shipment originated, the name of the person who took the animal or the name of the shipper, the address of the taker or shipper and, for transport through the state, the destination of the shipment. Hunter harvested carcasses, parts or meat taken outside Rhode Island shall also bear the marking, tagging or labeling required by the state where the animal was taken.
For more information, see the following resources:
- Rules and Regulations Governing the Importation, Feeding, and Baiting of Cervids in Rhode Island.
- Geist, V., et al. 2017. The Challenge of CWD: Insidious and Dire. Alliance for Public Wildlife, Living Legacy
- White Paper Publisher.Chronic Wasting Disease Alliance [Internet]. C 2002- 2017. Cited 28 June 2017. Available from: www.cwd-info.org.