Suspected disease outbreak among local deer
West Virginia Department of Natural Resources officials suspect an uptick in deer mortalities in Ohio County is the result of an outbreak of Epizootic Hemorrhagic Disease in the area.
The disease is caused by a virus primarily transmitted through flies normally called biting midges or no-see-ums. According to WVDNR Wildlife Disease Specialist Ethan Barton, the last EHD outbreak in Ohio County occurred in 2017.
Barton stressed the EHD outbreak in Ohio County was “nothing new,” as the WVDNR documents cases of EHD in the state “every year.” The WVDNR documents cases of Hemorrhagic Disease, including bluetongue disease and EHD. Numerous strains of two different viruses cause both types of hemorrhagic disease.
According to Barton, the WVDNR received the first report of sick and dead deer in the county “a few weeks ago.” He noted the outbreak coincides with when EHD “typically” appears in West Virginia during late August. EHD transmission will last in the area until the first hard frost of the year, which kills off the insect vectors.
The Ohio County outbreak was confirmed from tissue samples taken from a number of Ohio County deer over the last few weeks by WVDNR staff. The samples were submitted for diagnostic testing and are pending results at the Southeastern Cooperative Wildlife Disease Study.
Barton could not provide an exact number of EHD-infected deer in Ohio County but said there were “not a lot” of reports of sick and dead deer in the area. Barton said it was still too early in the outbreak to determine the extent of EHD’s impact on the local deer population.
“The outbreak in Ohio County kind of started within the last few weeks, probably around the same time I started receiving some reports of EHD in the Eastern Panhandle as well,” Barton said. “September is pretty much our peak EHD caseload, and by the time October rolls around, depending on what the weather is like, we usually see things cool off a little bit. We could continue getting reports until we get that first hard frost, which is a hard stop for the virus.”
Ohio County is not the only area in WV experiencing an EHD outbreak. WVDNR confirmed EHD activity in six counties in the state dating back to late July. At this time, WVDNR also has samples pending from three other counties.
The disease is spread by midges, which transmit the virus to deer when they bite them. Midges typically breed in wetter soils, such as mud. Barton stressed that “not every midge” is infected with the virus.
“It’s not a matter of every midge is carrying and transmitting the virus,” Barton said. “Some midges are infected, some are not, and it’s hard to predict what influences it. Some big lingering questions in the wildlife disease world are, ‘How does the virus show up, and where does it come from?'”
Once a deer is infected with EHD, symptoms include internal and external lesions, a swollen head, a swollen and protruding tongue with a blue hue, very dark pink or red eyes and rectal bleeding.
Barton said deer that have a “more chronic form” of EHD may look “pretty thin” and could also have hoof lesions and tongue ulcers.
According to Barton, EHD does not threaten human or pet health, as the virus does not spread through contact with infected deer or bites from midges. He outlined that once an infected deer dies, the virus is “pretty much dead” as well.
“There’s not horizontal transmission of EHD because the virus does not have a potential buildup of infectious material at the site like chronic wasting disease,” Barton said. “Once that infected deer is dead on the ground, that’s it, the virus is done.”
Barton noted hunters should also not be “terribly concerned” about the virus regarding meat safety.
“If a hunter harvests a deer and it seems like the deer is in good shape and they don’t notice anything out of the ordinary, the hunter can certainly decide whether they want to consume it,” Barton said. “If they notice signs of infection in the deer, such as puss, lesions or emaciation, the hunter would have the information to decide whether they want to eat the deer.”
Barton added not all animals in an area where EHD occurs will become infected, and not all infected deer will die. Deer that survive infection will be immune to reinfection by the same virus for a number of years.
It is common for residents to discover deer infected by EHD around bodies of water.
Barton said this occurs because a common symptom for the “typical acute variant” EHD is dehydration, which he suspected was the cause of deer deaths near bodies of water in Ohio County.
“Residents may see infected or dead deer near water because they’re trying to cool off or drink enough water to make up for the volume of fluids they’ve lost,” Barton said. “In West Virginia, you have a lot of roads that run near waterways and a lot of houses that are down in the hollows along creeks, so the deer are very visible by sight, and people can smell them as well.”
Jeff Miller, owner of Miller Farms, said a hot topic of discussion among local farmers has been the bodies of dead deer discovered at creeks in the area.
“When the last bluetongue outbreak happened in the area several years ago, it was the smell of the infected deer in the area that clued people into something going on,” Miller said. “It was sad because down in creek beds, there were dead deer that you couldn’t see but could smell them.”
Wellsburg-based farmer Eric Freeland has observed deer acting “peculiar” on his farm, including “staggering around.”
Freeland also found a couple of dead deer on his neighbor’s property, but he did not know the reason for their deaths.
“We saw deer out in broad daylight, which is fairly uncommon,” Freeland said. “These deer are highly stressed and probably dehydrated because it’s difficult to find water right now.”
Barton said the statewide drought that began in July has created conditions “ripe for good midge breeding.” This, combined with fewer water sources available for deer, has created an environment for the EHD to spread more quickly than in non-drought conditions.
“When you have a big dry-up and fewer available water sources for wildlife on the ground, the wildlife starts to move towards the same water sources,” Barton said. “It could be a pond or a small creek with a bunch of midges in it, and now more deer are gathered there because of the lack of available water.”
While local deer mortalities caused by the disease can “sometimes be noteworthy,” Barton said the EHD outbreak is “not a long-term threat” to the state’s deer populations. He added that the local deer population typically “recovers quickly” from whatever disease mortality they experience during an EHD outbreak.
“The main takeaway is that while this may seem concerning, this is not a long-term threat to sustainability or the overall health of the deer population,” Barton said. “This is a relatively normal thing that happens.”
Barton advised residents who encounter a number of dead deer to call their WVDNR district office and speak to their biological staff.
“We can walk them through with what they’re seeing and try to triage out what it might be,” Barton said. “We can collect tissue samples if needed and try to get some answers from there.”