Ashe deer dodge hemorrhagic fever bullet; surrounding counties hit hard
Last modified: Nov. 21, 2012
With the onset of cold weather, Ashe County may have dodged a hemorrhagic fever outbreak that did significant damage to white-tailed deer herds in northwestern North Carolina in the late summer and early fall.
“There were some reported cases in Ashe County — a total of nine — but nowhere near the number of cases reported in Wilkes,” said North Carolina Wildlife Resources Commission Biologist Chris Kreh.
Wilkes County reported 281 cases of hemorrhagic disease, according to Kreh, with a further 63 cases reported in Alleghany County mainly inside Stone Mountain State Park.
Hemorrhagic disease is one of the most significant infectious diseases, and affects white-tailed deer across the state.
Symptoms vary considerably, according to Kreh; some animals exhibit no symptoms while others may appear thin or weak.
If the animal survives with the disease for a long period of time, the deer may also lose a significant amount of weight.
Foot, mouth and internal lesions may also develop in addition to a high fever that forces deer to water — the reason many dead deer are often found near a water source.
“In terms of mortality — it's hard to say exactly — but we estimate 30 to 50 percent of affected herds will die,” said Kreh. “We've seen a significant drop in the deer harvest so far this year, including Ashe County, but we've also seen harvest declines in counties without disease outbreaks. We think fewer deer, combined with a really, really good acorn crop means deer don't have to move as much as they normally do.”
In July, the N.C. Wildlife Resources Commission reported observations of an “unusually high number of cases of hemorrhagic disease in white-tailed deer in Wilkes and Surry Counties,” and asked the public to report sighting of sick or diseased animals to the WRC.
Though the disease can strike in the summer, most reports usually come during August and September, according to Kreh, by biting flies called midges that spread from two related viruses — epizootic hemorrhagic disease and bluetongue virus.
“These outbreaks come and go with the lifecycle of these insects,” said Kreh. “We had this disease outbreak in early and late summer but as it got colder, we've had no new reports of the disease for about a month.”
At the peak of the outbreak, Kreh said as many as 10 additional disease reports were filtering into his office every day.
“It just really matters how many insects you have,” said Kreh. “Many folks think it's brought on by having too many deer, or by an ‘overpopulation' of deer, but that's really not the case.”
Kreh said it's difficult to gauge exactly why the outbreak was as bad this year in Wilkes, Surry and Caldwell Counties.
“Normally, in western North Carolina, we consider it an active year if we've had 100 or 200 reported cases of the disease,” said Kreh.
“This year, we've had more than 1,500 in the western part of the state alone. So, we've never seen as bad an outbreak as we did this year.”
A mild 2011-2012 winter leading to more insects, a particular virulent strain of the disease, and a deer herd with little to no immunity was likely, “a perfect storm,” according to Kreh.
“Most every deer that died went down quick,” said Kreh. “The difference between Ashe and Wilkes Counties was likely just an abundance of insects in Wilkes. Right at the edge of the Blue Ridge escarpment, where significant numbers of deer died, the combination of factors was perfect.”
Outbreaks are usually seen nearly every year across the state, though the last major outbreak occurred in 2007, according to the NC WRC. Other notable outbreaks occurred in 1939, 1955, 1961, 1971, 1976, 1988, 1994, 1999, 2000, 2002 and 2011.
“I'd also like to stress that deer are fine to eat,” said Kreh. “The disease itself poses no threat to people, and if you kill what appears to be a healthy deer, you're fine.”
At this point, Kreh said no changes have been made to state hunting regulations, but said they could be adjusted next year as the WRC gets a better picture on how much damage northwestern deer herds actually sustained.
“The good news though, is that when spring rolls around next year, the chance of an outbreak is much reduced,” said Kreh. “It'd be pretty unlikely to hit us two seasons in a row.”