Midges Drive Deadly Deer Disease Across Missouri, Michigan, and Wisconsin

Key points

• The Missouri Department of Conservation (MDC) has received reports of hemorrhagic disease (HD) in white-tailed deer, with outbreaks typically occurring between July and October.
• The Michigan Department of Natural Resources (DNR) confirmed the state’s first cases of Epizootic Hemorrhagic Disease (EHD) for 2026 in Branch, Ingham, Jackson, and Lenawee counties.
• HD is transmitted by biting midges and causes rapid death in deer, often within 8 to 36 hours of infection, with symptoms including fever, swelling, and loss of fear of humans.
• There is no treatment or vaccine for HD in wildlife, but the disease does not pose a risk to humans or pets, and venison from healthy deer remains safe to consume.
• Officials in Missouri, Michigan, and Wisconsin are urging the public to report sick or dead deer to help track the disease and monitor deer population health.

Background

Hemorrhagic disease outbreaks in deer have been reported across multiple states in recent weeks. In early September 2026, Wisconsin experienced a significant die-off, with nearly 900 reports of dead deer in southeastern counties, primarily Washington, Waukesha, and Ozaukee. Virginia also reported an outbreak, with officials noting that the disease is deadly to deer but poses no threat to humans. These outbreaks are typically driven by midges and tend to wane after the first hard frost.

How outlets are covering it

The Missouri Department of Conservation (MDC) emphasizes that HD is a naturally occurring virus in Missouri’s deer population, with outbreaks most common between July and October. MDC Wildlife Health Program Supervisor Brigid Niemeyer noted that while the disease kills deer quickly, it does not have long-term effects on the overall health or sustainability of Missouri’s deer herd. The Michigan DNR, on the other hand, highlighted the confirmation of EHD in four southern counties, stressing that the virus cannot be transmitted from deer to deer or to humans. Both agencies urge the public to report suspected cases to help track the disease. In Wisconsin, the DNR cautioned that numbers may include duplicates and noted that the outbreak could reduce local deer numbers this fall, though the overall deer population remains robust.

Why it matters

Hemorrhagic disease outbreaks can significantly impact local deer populations, affecting hunting seasons and wildlife management. While the disease poses no risk to humans, it can cause visible and rapid die-offs, leading to public concern. Monitoring and reporting are crucial for understanding the disease's impact and ensuring the long-term health of deer herds.

What to watch

Officials in Missouri, Michigan, and Wisconsin will continue to monitor the disease through public reports and laboratory testing. The outbreaks are expected to wane after the first hard frost, which kills the midges that spread the virus. Hunters and outdoor enthusiasts are advised to avoid processing visibly sick deer and to report any suspected cases to local wildlife agencies.