LANSING, Mich. (Michigan News Source) — Deer season hasn’t started yet, but Michigan’s herds are already facing a new threat.

The Michigan Department of Natural Resources (MDNR) has confirmed the state’s first cases of epizootic hemorrhagic disease (EHD) this year, detected in white-tailed deer from Eaton, Jackson, Van Buren, and Washtenaw counties.

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The virus, carried not by deer but by flies, has a grim reputation. A single bite from an infected fly can leave deer weak, disoriented, and often dead within days, according to the MDNR. Sick white-tialed deer are usually found slumped near rivers or ponds, having staggered to water in a fevered attempt to cool off.

There’s no risk to humans or pets, the MDNR emphasized, and venison from healthy deer is still safe. For local herds, however, the losses can add up.

“Occasionally, localized outbreaks have been detected in a dozen or more counties, including as many as thirty in 2012,” Brent Rudolph, the agency’s deer and elk specialist, said.

Early frosts are the only natural relief: once cold weather wipes out the biting fly population, transmission stops. Until then, hunters and landowners are being asked to report any sick or dead deer through the MDNR’s Eyes in the Field system to help track the spread.

While EHD rarely dents the statewide herd long-term, it can empty local woodlots for a season or two.