Wisconsin EHD deer deaths continue to climb

MILWAUKEE - An unusually high number of deer are dying in Wisconsin this season from epizootic hemorrhagic disease (EHD), according to officials from the Wisconsin Department of Natural Resources. 

EHD deer deaths higher than usual 

What we know:

The EHD outbreak had originally been reported to have begun in Washington County, but according to Erin Larson, a DNR deer herd health specialist, the outbreak has now spread across four counties in Wisconsin. 

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Washington County is seeing an uptick in EHD cases and is currently the county with the most reported cases at around 800. However, Waukesha County has reported about 200 suspected cases, while Ozaukee and Milwaukee have also seen some cases. All of these counties share in common that they border Washington County, and they all have confirmed EHD cases among the deceased deer. 

Larson also notes that the number of suspected cases during this outbreak far exceeds previous years' outbreaks. Typically, the first cases of deer that have died of EHD are reported in September, but this year, reports began rolling in at the beginning of August. According to Larson, this could mean a higher overall count at the end of the season. 

As of Sept. 8, the Wisconsin DNR has reported over 775 deer reported in Washington County, over 175 reported in Waukesha County, over 30 reported in Ozaukee County, and less than 10 reported in Milwaukee. 

Wisconsin deer EHD reports for 2026 

The backstory:

It was confirmed that deer were dying of EHD from a test on a deceased deer in Richfield in southern Washington County, according to Erin Larson, a Wisconsin DNR deer herd health specialist. 

It was noted that the outbreak also began earlier in the season than is typical, with outbreaks usually ending at the season's first freeze. 

Deer fatalities in Wisconsin

What we don't know:

It still remains to be seen what the total number of deceased deer from the outbreak will be. 

However, Larson previously reassured that despite the high number of deer deaths occurring, deer herds are usually able to bounce back from the population decrease rather quickly. 

EHD in deer explained 

Dig deeper:

EHD, or epizootic hemorrhagic disease, is a virus that impacts white-tailed deer and other hoofed animals, according to Wisconsin DNR. The disease is most often fatal and usually kills the animal within a week of infection. 

It is caused by either the bluetongue virus (BTV) or the epizootic hemorrhagic disease virus (EHDV). When the disease regularly occurs in a deer herd population, death rates are lower, typically killing less than 25% of the deer population. 

However, in areas like Wisconsin, where the disease is less common, death rates are usually higher and high density herds will suffer higher fatality rates. 

EHD is transmitted by biting flies, usually midges, so the disease is typically most prevalent when the fly population is most abundant, in late summer and fall. The virus cannot last long outside the insect or its host. 

Can people or pets get EHD?

Why you should care:

The disease does not pose a risk to humans. Humans cannot contract the virus by handling infected deer, eating venison, or being bitten by infected insects. 

It also does not impact common household pets, such as cats and dogs, according to Idaho Department of Fish and Game.

Deer symptoms of EHD

Clinical Signs:

It is virtually impossible to distinguish between hemorrhagic disease caused by BTV or EHDV. Symptoms of the infection in deer vary depending on what stage of the disease the deer are in and how long they have been infected. 

Potential signs of infection include: 

• A lack of fear of humans
• Excessive salivation
• Foam present around the nose (sometimes with blood)
• Look weak despite having a good body condition
• Appear to have parts of the body swollen (usually the head and neck)

The deer will also often appear near water sources, as they head there to try to combat their high fevers and dehydration. 

EHD history in Wisconsin 

Timeline:

Wisconsin deer were first confirmed to have EHD in the fall of 2002 when 14 deer were found dead suddenly in Iowa County. Blood samples from deceased deer were collected and tested between 2002 and 2011 and the results did not find antibodies to BTV or EHDV. 

This implies that Wisconsin deer are not exposed routinely enough to these diseases to have developed any antibody resistance. Some deer, such as those in the southern and western U.S., have built up more antibodies against these viruses. 

Outbreaks have varied in the number of deer killed by the viruses throughout the years. One of the most fatal outbreaks in recent years was in 2019. Crawford, Grant, Iowa, La Crosse, Richland, Sauk, and Vernon counties reported deer deaths ranging from 1 to 226 per county. The highest number of deer deaths were seen in Crawford County. 

The identification of EHD happened in 1955 in both New Jersey and Michigan, according to the Michigan DNR. Hundreds of white-tailed deer had died of the disease, which had not been seen before.

Reporting sick or deceased deer 

What you can do:

If you spot a deer carcass or a deer that appears sick, you can report this to the Wisconsin DNR by emailing the agency at DNRWildlifeSwitchboard@wisconsin.gov or by calling 608-2267-0866. 

When you contact Wisconsin DNR, they ask you to include the following information: 

• The number of dead deer
• If the deer is sick or dead
• The specific location where you saw the deer, including the county
• Your contact information

You do not have to report deer that you see killed on the roadway for health reporting. The department also does not have the resources to remove the dead deer. 

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