State of Wisconsin
Chronic Wasting Disease Management Recommendation

Regulation of Baiting & Feeding
April, 2002

Issue: Chronic Wasting Disease (CWD) has been discovered in Wisconsin's wild deer herd in Deer Management Units 70A and 76. Baiting and feeding deer is a common practice throughout the state and is considered a potential risk factor in managing the disease. The State of Wisconsin needs a science-based policy recommendation to guide the development of regulations for baiting and feeding as part of a comprehensive response to CWD management.

Recommendations:

1) The State of Wisconsin should consider its wild deer population a single at-risk population for purposes of CWD management. The deer population in DMU 70A and 76 is not an isolated population of deer. CWD has probably existed in Wisconsin's wild deer population for several years prior to the first positive test reporting (February 2002). There has likely been opportunity for the disease to spread to other areas of Wisconsin through natural deer dispersal or perhaps even movement of CWD-contaminated carcasses. CWD test results are available for less than half of Wisconsin.

2) The State of Wisconsin should prohibit the baiting and feeding of deer statewide. Baiting and feeding, including the use of protein and mineral supplements, congregate deer. Congregation of deer increases the opportunity for CWD-infected deer to transmit CWD to healthy deer.

Background: Many questions remain about how CWD is transmitted. However, experts believe that animal to animal contact is important in spread of the disease. Transmission may also be possible from environmental contamination. The highest prevalence rates of CWD have been found in wild and captive situations where deer densities are high and there is frequent congregation over artificially provided food sources. It has been thought that limiting the volume of feed available might be sufficient to limit deer contact time, and therefore the rate of disease transmission. However, recent research on bovine tuberculosis in Michigan has shown increased deer contact rates over small volumes of food vs. larger volumes. International disease experts have recommended to Michigan that they will not be able to eliminate deer TB unless there is a complete prohibition on deer baiting and feeding.

Deer dispersal movements of up to 50 miles have been observed in studies with radio-collared deer in the Midwest. The potential exists that a larger area of Wisconsin has been exposed to CWD through the natural movement of CWD-infected deer from the endemic area of Iowa and Dane counties.

Research indicates that CWD prions are difficult to destroy; normal environmental degredators like UV radiation, desiccation, or temperature extremes will not destroy CWD prions. Concentrations of infectious prion could occur if infected deer regularly congregate in small areas around food sources.

Feeding deer enables the environment to support more deer throughout the year than might otherwise be possible. Disease spreads more quickly through denser populations thus, feeding deer works directly counter to deer population control needed to contain or prevent transmission.

The factors that may have introduced CWD into Wisconsin (such as movement of captive deer and elk or deer carcasses) will continue to exist in the state even with new surveillance and control efforts. Since repetition of such an event is possible, everything possible must be done statewide to prevent factors that will allow establishment of a disease. Prohibiting feeding and baiting is important to preventing establishment and protecting wild deer, livestock, and human populations from CWD, bovine tuberculosis, and other significant infectious diseases.

The CWD Interagency Health and Science Team approved this recommendation on April 23, 2002.