ASHLAND — Ashland, Richland and Knox counties continue to see increased reports of deer that are sick or have died from epizootic hemorrhagic disease, or EHD.
As of Sept. 23, the Ohio Division of Wildlife has reported 20 cases in Ashland County, 18 cases in Knox County and 14 cases in Richland County.
Status of EHD
Clint McCoy, a longtime deer biologist at ODW, gave a virtual presentation about the status of EHD in Ohio on Sept. 9.
McCoy said 2025 is the most significant EHD outbreak in Ohio, and the outbreaks will continue until the first hard freeze of the season.
At that presentation, McCoy said among 5,000 reports of dead or sick deer, 22 counties confirmed EHD cases in free ranging deer. As of Sept. 23, 32 counties confirmed EHD in deer and there are roughly 8,200 reported cases.
Southeast Ohio continues to be the most impacted by EHD outbreaks, specifically in Athens, Meigs, Washington, Morgan, Noble and Monroe counties.
McCoy said EHD has continued to expand northward since 1980. Because northern states have less frequent exposure to EHD compared to southern states, deer have low immunity, and therefore more severe outbreaks.
Eventually, herds will develop resistance to EHD after more frequent exposure.
The first severe EHD outbreak in Ohio was in the early 2000s in southeast Ohio. By 2007 it reached north central Ohio and in 2012, EHD cases were scattered across the state, McCoy said.
“EHD is unpredictable about location and severity,” he said.
But EHD is becoming endemic, which means it regularly occurs in Ohio from year to year.
He theorized 2025’s particularly deadly outbreak can be attributed to three primary reasons:
- Warmer spring temperatures allow midge flies to breed sooner and build population.
- Higher than average rainfall in July created water pools, which provided ideal breeding environments for midge flies.
- Lower precipitation in August receded larger water pools, leaving shallow muddy water, which again created ideal breeding environments.
“Each of these factors will individually contribute to a hemorrhagic disease outbreak, but when you take them all together, they kind of provide the ultimate recipe for a significant outbreak,” McCoy said.
Midge flies bite deer, infecting them with EHD.
McCoy said there is not much the division or public can do to prevent the outbreak, but he did encourage people with water sources on their property, such as ponds, to ensure the water is good quality. Midge flies typically breed in low-quality water sources.
He said hunters can reduce harvesting does to try to jumpstart a herd recovery.
“Immediate impacts of hemorrhagic disease can be severe, they can be frustrating, they can be demoralizing, disheartening. I know there’s lots of people who put in lots of resources into managing deer on their property… and I understand that,” McCoy said.
EHD does not pose a long-term impact; populations typically recover within three to five years depending on the severity of the outbreak.
Report sightings of sick or dead deer through ODW’s website, call 1-800-945-3543, or call the county wildlife officer.
Chronic Wasting Disease
McCoy also spoke about chronic wasting disease, or CWD, which is a fatal neurological disease similar to mad cow disease.
The Ohio Division of Wildlife has expanded surveillance areas this year to include new townships in Morrow, Crawford and Delaware counties that are within a six-mile buffer zone of confirmed CWD cases.
CWD was first detected in Ohio in 2020 in southern Wyandot County, where there were two positive cases. In 2024, there were 24 confirmed cases, which were still most prevalent in Wyandot County, but cases showed expansion to other nearby counties.
McCoy said the disease is spread through animal-to-animal contact or through feces, urine and decaying carcasses, which can remain infectious in the wild for years.
“Once chronic wasting disease is established, it’s permanent on the landscape,” McCoy said.
That means the disease will continue to decrease populations and suppress population growth potential.
There have been no confirmed positive cases of CWD in Ashland, Knox or Richland counties.
