Tom Morang
05-01-2002, 07:00 AM
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.
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.