October 2, 2006
Although chronic wasting disease represents a significant threat to
infected deer and elk populations, there is no evidence that chronic
wasting disease occurs in South Carolina, according to the state natural
resources agency.
However, it has been documented in wild deer and/or elk herds, as well as,
captive or farmed herds in a number of Western and Northeastern states. The
S.C. Department of Natural Resources (DNR) has been conducting surveillance
for chronic wasting disease in South Carolina since 1998, and this
surveillance will continue and likely be increased due to the spread of
chronic wasting disease in the West and Northeast.
But hemorrhagic disease is the most significant disease of deer in the
Southeast, according to Charles Ruth, DNR Deer/Turkey Project leader. Each
year during late summer and early fall as deer hunters begin their
activities, DNR is contacted about an occasional sick or dead deer that is
found. Although there are a number of diseases that can cause sickness and
death in deer, the most likely cause during the late summer and fall is
hemorrhagic disease. The disease is caused by certain viruses that are
transmitted by biting midges or gnats, commonly called no-see-ums. The
seasonality of the disease is related to the life cycle of these insect
vectors since they thrive during the warmer months in the Southeast. Simply
put, the better the conditions are for midges, the greater the chances are
that hemorrhagic disease will be spread to deer.
In addition to being seasonal, hemorrhagic disease appears to flair up
about every three to five years, Ruth said. This is probably related to the
fact that once deer are exposed to the disease they are more resistant to
it. Therefore, if you have disease one year the deer become exposed or
inoculated to the disease and you do not see much disease activity until
there is turnover in the deer population. After several years you are
dealing with another group of deer and their systems are “naive” to the
disease. The last time there was significant hemorrhagic disease activity
in South Carolina was in 2002, therefore, disease activity could be
relatively high this year.
Symptoms of hemorrhagic disease include poor physical condition, sloughing
hooves, abrasions or sores on the brisket and legs, and ulcerations on the
mouth, tongue, and rumen (stomach). Actual verification of the disease must
be through laboratory analysis of blood or certain other tissues. DNR has
monitored for hemorrhagic disease since about 1980 through an effort
directed by the Southeast Cooperative Wildlife Disease Study, which is part
of the School of Veterinary Medicine at the University of Georgia. Through
this process, the Southeast Cooperative Wildlife Disease Study has
determined that hemorrhagic disease is common over most of the Southeast.
The severity of hemorrhagic disease varies annually and geographically with
cases being mild and scattered in some years while in other years
significant outbreaks and mortality can occur.
Deer likely die in South Carolina each year from hemorrhagic disease,
however, there is no indication that a major outbreak has occurred in the
state since the mid 1970s, according to Ruth. The disease is part of life
for deer in the Southeast and fortunately, it appears that Southeastern
deer have acquired some immunity to the disease. Northern deer, on the
other hand, are not exposed to the disease as frequently since the insect
vector is not as common in cooler climates. For this reason, significant
outbreaks and mortality from hemorrhagic disease are more likely in
Northeastern deer populations.
Although it is important for hunters to report sick or unexplained dead
deer to the DNR, there is little that can be done to prevent hemorrhagic
disease since it is spread by insects rather than from deer to deer. As
with any recommendation for disease prevention, DNR encourages hunters to
keep deer populations at reasonable levels, which leads to overall good
herd health. The disease does not pose a threat to hunters, however,
hunters should not consume deer or any other game that appears sick or in
poor condition.
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