A whitetail buck stumbles around, acting much like a zombie with no cares or fears of human activity. Eventually, it walks over to a pond, wades into the cool water, and lays down into a watery grave. Less than 24 hours after showing signs of Epizootic hemorrhagic disease (EHD), the deer is dead.
Understanding Epizootic Hemorrhagic Disease (EHD)
EHD is part of the Hemorrhagic Disease (HD) family of viruses. It comes in numerous strains, including EHDV, EHDV-2, and EHDV-6. The infamous and well-known bluetongue virus (BTV) is also closely related to EHD. It operates the same way and has the same effects.
EHD should not be confused with chronic wasting disease (CWD), which is not caused by a virus or bacteria, but a prion (malformed protein). CWD is passed directly from deer to deer, or from deer to contaminated areas to other deer. It’s a highly contagious disease.
In contrast, HD, EHD, and BTV are viruses, but are not passed from deer to deer. Instead, deer contract these viruses from the bites of small midge flies (Culicoides midges), which are commonly referred to as “no-see-ums.”
Not all midge flies carry the EHD or BTV viruses. Many do, though. Once whitetail deer are bitten by the infected midge, they usually remain asymptomatic for up to a week. Once they show signs of the disease, most die within 24-36 hours.
At onset, deer begin to run high fevers, which is why EHD-infected deer often die close to water; they visit creeks and ponds in an effort to lower the fever. Other symptoms include swelling of the neck, head, and tongue, as well as lameness, and loss of fear of humans.
While many deer die from this disease, while others do survive. They can develop antibodies that provides immunity to them and their offspring.
The first hard frost of the year kills off the midge fly population. This ends the EHD outbreak until it rises again the next year, or years after.
There are no known risks of EHD infecting humans, whether through the bite of the midge fly or by consuming deer with the HD virus. That said, it’s recommended not to consume meat from animals found sick or dead.
The Perfect Storm for EHD: A Widespread 2025 Outbreak
The perfect storm for widespread EHD impacts include a wet spring and early summer followed by a mid- to late-summer drought. This scenario creates the perfect conditions for midges to proliferate. It’s the ideal environmental factors for reproduction. Much of the country has experienced these this year, and it’s led to a widespread outbreak in 2025.
The 2025 EHD outbreak seems to be one of the largest on record. Many states are reporting cases, including Indiana, Kentucky, Ohio, Idaho, Maryland, Michigan, Missouri, Montana, Tennessee, Virginia, Washington, West Virginia, and more. With a month or more until first frost, others will likely be added to the list.
The Hardest Hit Areas This Year
Although HD occurs in most states each year, some are being more impacted than others. This year, Indiana, Kentucky, Ohio, and West Virginia seem to be encountering the worst of the disease.
Indiana
Indiana is seeing another big outbreak, too. The southern third of the state is being hit hard. Jennings, Jackson, Martin, Bartholomew, Switzerland, Orange, Jackson, and surrounding counties, are among the most heavily impacted areas. Most counties in southwestern Indiana, and along the Ohio River, aren’t seeing as large of an impact. You can keep up with HD disease spread in Indiana here.
Kentucky
Kentucky is seeing a significant EHD event, too. According to Joe McDermott, the deer program coordinator for the Kentucky Department of Fish and Wildlife Resources (KDFWR), the Bluegrass State has logged approximately 1,000 reports of HD so far this season. He says this is up over the “usual” EHD events typically seen each year. That said, it’s nowhere close to the 2012 or 2017 Kentucky outbreaks.
“As of now, this isn’t the worst EHD event we’ve ever seen,” McDermott said. “In comparison, we had reports of more than 4,000 deer dead in eastern Kentucky in 2017. However, we still have another month or so to go until we get those killing frosts. Hard to say what the end result will be as of now.”
While many of Kentucky’s past outbreaks were more regionalized, this year, it’s more of a statewide event. That said, western Kentucky is seeing a greater impact.
“We also have several cases awaiting results from the lab,” McDermott said. “So, this county map can and will change as we roll through this.”
Oftentimes, you hear anecdotal numbers of the percentage of deer herds lost to the disease. While hunters can provide localized numbers, the state agencies can’t provide official numbers until they conduct winter herd deer surveys.
“It’s hard to say the percentage of deer population lost in the worst affected counties,” McDermott said. “That will probably reveal itself over the course of the year and when we run our models. Thankfully, many of the worst affected counties are in portions of the state where population overabundance is rampant. So, even though we will see localized die offs, I do not think that this year will be enough mortality to decimate the population. It should rebound to ‘normal’ levels within a couple of years.”
Follow along with the spread of HD in Kentucky via this map.
Ohio
Without question, Ohio is seeing the worst outbreak of 2025. Clint McCoy, a deer biologist with the Ohio Division of Wildlife, notes just how bad it is this year.
“It appears to be the largest mortality event that I have seen in my career here in Ohio,” McCoy said. “I started in 2014. Prior to that, we didn't have the ability to track reports from the public like we do now. I cannot speak to the significance of this outbreak compared to those that have been experienced in other states.
According to McCoy, last year, Ohio had about 2,000 reports, with most in northwestern Ohio — specifically Defiance and Paulding counties bordering Indiana. This year, it’s much worse.
“As of Sept. 15, we had about 7,500 reports of dead/sick deer across the state, with the majority of those reports (about 5,000) coming from the three county area along the Ohio River (Athens, Meigs, Washington).”
Once again, the DNR can’t provide details on percentages of the herd lost, even in the worst-impacted areas. That said, I’m hearing anecdotal reports from landowners saying as much as 80% of the deer herd is being lost in the hardest-hit areas. Additionally, based on comparable outbreaks from past seasons, McCoy expects at least a 40% to 50% decline in the antlered deer harvest this season.
“Efficient and effective population surveys are conducted via aircraft in winter (since methodology requires leaf-off conditions),” McCoy said. “We recently purchased an IR sensor to mount to our aircraft and have plans to utilize it this winter in these areas to determine the extent of mortality, as well as monitor these areas over the next several years to document the timeline of herd recovery.”
Keep up with the 2025 Ohio HD outbreak here.
Other States
Other bordering states, such as western West Virginia, western Pennsylvania, and other areas, are seeing significant events, too. Additionally, other areas, such as Maryland and Virginia, among others, are experiencing notable HD outbreaks.
Incoming Changes to the 2025 Deer Season?
Online and at camp, hunters are talking about rumors of changes to deer seasons in affected areas. These rumors continue to float around, especially for southeastern Ohio. That said, it’s not likely to happen. At least, not soon.
“A rule change (bag limit reduction in the most-affected counties) was proposed at a special (previously unscheduled) meeting of the Wildlife Council on September 17,” McCoy said. “The rule change, should it pass, wouldn't take effect until December 1 (the start of our 7-day firearms season).
"This is one of the reasons (the question above hints at the other reason) why we haven't responded with regulation changes in the same year of an EHD outbreak before — the timeline of a rule change is long.
“There is no mechanism in place that could alter regulations prior to the season opening once we get this far into the calendar. The proposed rule change is now in a 30-day comment period, and the rule could be amended (based on feedback), prior to the final vote of the Wildlife Council.”
Interestingly, the southeastern region of the state is the region with the highest deer population. According to McCoy, the percentage of the annual antlerless harvest taken by landowners is the highest in this area of the state. He says Washington County is No. 1 (47% of the antlerless deer being taken by landowners), Meigs County is No. 2 (46%), and Athens is No. 4 (42%).
“In this region, where EHD impacts are most significant, those most familiar with local conditions (landowners) are the same folks that have a substantial influence on the annual antlerless harvest,” McCoy said.
“While rules have been proposed to reduce bag limit, these landowners are the ones that have ultimate control on what is harvested on their properties and can make decisions on whether harvesting an antlerless deer this year is warranted.
"While we can't stop EHD, we know that populations do rebound, and the timeline for herd recovery can be jump-started by making wise harvest decisions in areas that have been impacted the most.”
What Can Hunters Do?
If you’re in an area with a current HD outbreak, do your part and report cases you discover. Furthermore, self-restrict doe harvests. This will help the deer herd bounce back quicker. Otherwise, it just takes time.
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