An outbreak of Epizootic Hemorrhagic Disease (EHD) is impacting deer primarily in south central Iowa, with the largest concentration of infected animals being reported in Warren County, according to the Iowa Department of Natural Resources.
An updated report late last week, raised the number of dead deer to 583, said Tyler Harms, Iowa DNR wildlife biometrician.
Harms said most of those 583 deer were reported in Warren County, but there have been reports in other counties, including two in Henry County, two in Van Buren County, seven in Davis County, two in Wapello County and 10 in Des Moines County.
Plus, Harms said, there also are more deer on the landscape suspected to be dying from EHD.
EHD is caused by a virus spread by female midges that feed on deer.
“Midges are the ‘no-see-’ems,’ the gnats that pester us when we’re outside,” explained Harms. “They are not a mosquito, but a biting insect.”
A deer bitten by a midge carrying the virus develops EHD. The disease causes high fever in deer and the cell membranes in their heart, lungs and diaphragm to weaken and burst. Infected deer are attracted to water to combat the fever and dehydration due to the hemorrhaging and usually die within a few days.
The midges carrying the virus are not a health risk for humans. Harms also pointed out that there is no risk in consuming a harvested deer that might have EHD.
“We see it every year in varying degrees,” Harms said. “We have been monitoring it for about six or seven years, since the first big outbreak in 2012 in southeast Iowa. It is dependent on the weather.”
In dry years, EHD 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. EHD remains active until rain disperses the deer, wind disburses the midges or a heavy frost kills the insects.
Harms said EHD is not a new disease, and it is not related in any way to chronic wasting disease.
“EHD and CWD are often confused, but they are very much different in terms of impact, manifestation and transmission,” he said.
According to the Quality Deer Management Association website, EHD is spread by biting midges; it cannot be spread from deer to deer. Symptoms of EHD include fever and internal hemorrhaging, but some deer can survive the infection. The Iowa DNR describes CWD as a neurological disease belonging to the family of diseases known as transmissible spongiform encephalopathies or prion diseases. It attacks the brain of infected deer causing the animal to lose weight, display abnormal behavior, lose body functions and die. CWD can be spread from deer to deer, and it is always fatal.
CWD has been found in wild deer in four Iowa counties: Allamakee, Clayton Wayne and Dubuque, and the DNR continues to monitor samples supplied by hunters during deer hunting season.
DNR officials are predicting the number of deer lost to EHB is likely to increase as bow hunters head to the timber to begin placing their tree stands.
People who come across dead deer, especially near a water source, should report the find as suspected EHB to a local wildlife enforcement officer or local conservation officer, advised Harms. “Being near a water source, that’s the No. 1 criteria for possible EHB.”
Whether deer die because of EHB or CWD, the DNR keeps count to monitor the diseases and to help with deer management planning, explained Harms.