Wisconsin wildlife officials are tracking more than 2,300 reports of deer suspected of dying from epizootic hemorrhagic disease across eight southeastern counties, a sharp expansion of an outbreak first confirmed in August.
In an update posted Oct. 20, the Department of Natural Resources said EHD has been laboratory-confirmed in wild deer in Fond du Lac, Sheboygan, Washington and Waukesha counties. Suspected cases have also been reported in Dodge, Jefferson, Milwaukee and Ozaukee counties.
Washington County accounts for the largest concentration, with just over 1,300 reports, followed by roughly 630 in Waukesha County. The agency listed about 170 in Dodge, 140 in Ozaukee, 50 in Jefferson, 40 in Milwaukee, 30 in Sheboygan and fewer than 10 in Fond du Lac. Those figures are estimates based on community and biologist reports, not a count of laboratory-confirmed cases or a complete census of deer mortality. The DNR said it is prioritizing sampling in places where the virus has not already been confirmed.
Outbreak grew from two confirmed deer
The outbreak began with two wild deer found near Richfield and West Bend in Washington County. The DNR’s Aug. 18 confirmation followed landowner reports of clusters of otherwise healthy-looking deer found dead in or near water. Infected deer can develop high fevers, become weak or unusually approachable and show excessive salivation or foam around the mouth.
EHD is transmitted by biting midges and does not infect people, including through handling deer, eating venison or midge bites, according to the DNR. Outbreaks typically diminish after the first hard frost kills the insects. Wisconsin deer have limited historic exposure, which can produce substantial localized mortality even though the agency says affected populations generally rebound.
Cattle case adds farm vigilance
The outbreak has also reached livestock. The Department of Agriculture, Trade and Consumer Protection confirmed EHD in non-lactating dairy cattle in Waukesha County on Sept. 29, the state’s first reported cattle case since 2013. Symptoms are uncommon and usually mild in cattle, but DATCP said sores, lameness or fever can resemble foreign animal diseases. Farmers who observe symptoms should work with a veterinarian on testing; EHD must be reported to the department within 10 days.
For hunters, the DNR said in a Sept. 22 herd-health update that the 2026 deer season would proceed under existing regulations without reduced harvest opportunities. Officials cautioned that county totals measure reports rather than total impact, and they continued to ask residents to report recently dead deer—especially animals found near water—through the state’s sick-or-dead wildlife form.
The practical distinction is important: the current numbers show an unusually broad, concentrated wildlife event, but not 2,300 confirmed infections. Continued reports will help the state map its reach until colder weather interrupts transmission statewide.
