Chronic Wasting Disease: Methods for Preventing the Spread

Chronic Wasting Disease: Methods for Preventing the Spread

By Cassie Sherwood, student at Northwest Missouri State University

Chronic Wasting Disease (CWD) is a fatal, neurological disease which has blighted North American deer, elk, and moose populations since the 1980s. CWD is a progressive disease, taking up to three years to show signs in infected animals. Eventually, the disease will affect the spinal cord, brain, and other muscular tissue. Scientists suggest that the disease originates from abnormal development of proteins throughout the body, and consequently influences the functioning of normal proteins, thus leading to the progressive nature of the disease. CWD is thought to spread through animal contact, bodily fluids, and the surrounding environment that infected animals reside in. The 2023 reports from the CDC state that the presence of CWD within the United States has been estimated to span across 31 states, primarily within the Midwestern region.

The Iowa DNR strongly relies on landowners and active hunters for surveillance of infected white-tailed deer populations. Since the disease’s original detection in Iowa in 2013, the DNR uses the reports of sick deer and harvesting to maintain surveillance and establish management practices. The 2023 Iowa Hunter’s Guide designates Deer Management Zones, which are areas or counties that the disease has been located in. Provided that CWD is spread through animal contact, it is highly localized in areas where deer have already been confirmed as disease positive. In these zones, additional tags for the season are often handed out, to encourage maximized harvesting in the areas. Some of the areas that have higher densities of infected populations have specialized hunting seasons to prioritize the removal of CWD positive deer.

When hunting in infected areas, hunters are encouraged to have the deer they harvest tested for CWD, especially within management zones established by the DNR. Testing can be done through submitting tissue samples to the DNR. Deer heads are deposited at identified freezer locations for collecting sample tissue to complete the testing. For deer that test positive, it is recommended that hunters to not consume the meat. For tissues that might be contaminated, the Centers for Disease Control and Prevention has released processing and carcass disposal suggestions for hunters. Due to the manner of the disease spreading through fluids, disinfecting tools and keeping meat from individual animals separated are highly suggested to avoid cross-contamination. Most importantly though, to reduce the spread of CWD, methods of carcass disposal such as burying or placing in a landfill is also advised. Instances where these methods aren’t an option, leaving the carcass at the harvest site will reduce the possible spread to more counties.

This fatal disease has continually spread countrywide since its original detection. New York is the only state to have successfully eradicated CWD, even with high numbers of cases located in surrounding states. In 2005, seven cases were confirmed in New York. Following this discovery, the state implemented several CWD regulations, which would evidently reduce the contamination and influence the spread. The state prohibits importation of captive deer, elk, and moose across state lines. Additionally, carcasses or heads of the species cannot be transported into New York, apart from deboned meat, antlers with no flesh, cleaned mandibles, and raw or processed hides. This regulation has been adopted by other states, such as Iowa. The state also prohibits feeding of wild deer and moose, which reduces contact with saliva.

The New York course of action cost approximately $1M, however, the eradication was swift and efficient. States have not implemented several of the regulations that NY enforces, possibly due to the cost. Perhaps leaning into methods that have already successfully eradicated CWD from New York could decrease the prominence of the disease within other states. Even following suit in establishing a few shared regulations could create a difference.


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