A fatal deer disease spread by a tiny, flying insect has been confirmed in wild animals in Minnesota for the first time, killing several deer in Stearns County.
The Minnesota Department of Natural Resources on Wednesday confirmed the first two cases of epizootic hemorrhagic disease (EHD) in wild white-tailed deer. The disease has been killing deer in nearby states for years, and was confirmed to kill tame deer on farms in Minnesota in 2018 and earlier this month.
While the disease usually hits in isolated pockets, wildlife managers say it has the potential to “dramatically reduce a local deer population in the short-term.” Iowa is experiencing an outbreak this year that has killed several hundred deer in the south-central part of the state.
“All of our neighboring states have been dealing with EHD for years,” said Lou Cornicelli, DNR wildlife research manager, in announcing the finding. “So it was always a question of when it would show up in Minnesota.”
EHD comes on the heels of a widening outbreak of chronic wasting disease which is spreading and killing deer across the U.S., including Minnesota, Wisconsin and the Dakotas.
The DNR suspects several deer in the St. Stephen area have recently died from EHD. Tests from two of the deer were positive for EHD; other deer were too decomposed to test. The outbreak is limited to Stearns County in central Minnesota. The disease incubates for 5-10 days, and most infected deer die within 36 hours of exhibiting symptoms.
The outbreak should end when the midges get zapped by the first frost of autumn. But it’s possible that the insect and disease become more prevalent under warmer conditions due to climate change.
“EHD is both naturally occurring and seasonal,” Cornicelli said. “Given our cold temperatures, we can expect to see a shortened period of infection as frost will kill both the virus and midge that carries it.”
The Minnesota Board of Animal Health confirmed EHD in two captive deer in Houston County on Sept. 5. Those cases appear unrelated to the Stearns County case. The disease first appeared in Minnesota captive deer in October 2018 in six deer on a Goodhue County farm.
Wisconsin, Nebraska, Iowa, Illinois, Michigan and Ohio report EHD deer deaths almost every year. Finding multiple dead deer near a water source is typical of an EHD die-off. Fever drives the animals to seek water, but they die from internal lesions and hemorrhages.
People who find a dead deer should report it to the nearest DNR area wildlife office. As with chronic wasting disease, EHD is not considered a threat to humans or animals outside the deer family. Still, people are warned to not consume meat from deer that appear to be sick or in poor health