Two diseases affecting deer in Iowa are being closely monitored heading into the fall of 2012.
The first disease, Epizootic Hemorrhagic Disease, or EHD, has been widely reported throughout Iowa and neighboring states. Losses due to EHD occur annually, usually at low levels and in localized areas. In dry years it can be worse as deer are more concentrated around water, and since the disease is spread by a biting midge, more deer can become infected.
It is important to know that deer being affected by EHD will be temporary. EHD will only remain active until rain disperses the deer by providing more watering areas or a heavy frost kills the midges.
EHD causes high fever in infected deer and also causes the cell walls in their heart, lungs and diaphragm to weaken and burst. The deer are attracted to water to combat the fever and dehydration due to the hemorrhaging. Most deer die in 1-4 days after being infected with EHD.
The last widespread outbreak of EHD in Iowa was 1998. The impact on hunting was minimal overall, but localized areas could see reduced numbers.
The second disease, Chronic Wasting Disease (CWD) is a neurological disease affecting deer and elk. It is caused by an abnormal protein – known as a prion – that essentially eats holes in the brains of infected animals. In the latter stages of the disease, animals appear disoriented, lethargic and emaciated. They often exhibit excessive thirst, salivation, urination and drooping head and ears. It is always fatal to the infected animal. Anyone seeing a deer exhibiting these symptoms should immediately contact the Iowa DNR.
It is important to know that CWD is spread by direct and indirect contact as the prions are shed in the bodily fluids of infected animals and can remain infective for years in the environment.
CWD was first discovered in northeastern Colorado in 1967. Since then, CWD has been detected in free-ranging populations in Colorado, Illinois, Kansas, Maryland, Minnesota, Missouri, Nebraska, New Mexico, New York, North Dakota, South Dakota, Texas, Utah, Virginia, West Virginia, Wisconsin, Wyoming and in Alberta and Saskatchewan, Canada. It has been detected in captive facilities in Colorado, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, New York, Oklahoma, South Dakota, Utah, Wisconsin and Wyoming, and in Alberta and Saskatchewan, Canada.
The Iowa DNR was informed by Texas Veterinary Medical Diagnostic Laboratory that a deer from a shooting preserve in Davis County tested positive for CWD. The National Veterinary Services Lab in Ames confirmed the positive test and Iowa is implementing its CWD containment plan. None of the other samples submitted tested positive. Beginning this fall the DNR will be working with hunters and landowners in this area to collect samples from hunter harvested deer. Testing will continue in other parts of the state as well.
Iowa has tested over 42,500 wild deer and over 4,000 captive deer and elk as part of the surveillance efforts since 2002 when CWD was found in Wisconsin. Samples are collected from all 99 counties in Iowa; however the majority are taken in the counties nearest to areas where CWD has been detected in other states. Samples are collected voluntarily from hunter-harvested deer at check stations and meat lockers. The Iowa Department of Natural Resources is keeping a close eye on the deer population as a disease spreads across the Midwest.
“What we are doing is an important part of the national CWD surveillance and monitoring effort,” said Dr Dale Garner, bureau chief for the wildlife bureau. “It is needed to give us a good picture of what is going on within the deer population.”
Hunter participation was completely voluntary and the DNR thanks all hunters that assisted with the CWD surveillance by providing deer heads for testing.
Note: It should be pointed out that this testing for the CWD agent is not a food safety test. At this writing, it is not believed that humans can contract CWD by eating venison; however, the Center for Disease Control and the World Health Organization recommends that hunters do not eat the brain, eyeballs, or spinal cord of deer, and that hunters wear protective gloves while field dressing game.
Also, hunters cannot transport into Iowa the whole carcass of any cervid (i.e., deer, elk, moose or caribou) taken from a CWD endemic area within any state or province. Only the boned-out meat, the cape, and antlers attached to a clean skull plate from which all brain tissue has been removed are legal to transport into Iowa.