BY DAVE SAMUEL / For the Dominion Post
Hunters are reporting deer dying from hemorrhagic disease along streams in areas around West Virginia. To date, deer have been found in Barbour, Harrison, Greenbrier, Monongalia, Monroe, Nicholas, Summers and Taylor counties.
This does not mean that the disease is found throughout those counties, just in isolated areas within them.
Hemorrhagic disease is caused by either the epizootic hemorrhagic disease virus known as EHD, or the blue tongue disease virus and known as BT. For our purpose, I’ll lump them together and refer to them as hemorrhagic disease (HD).
HD occurs when an infected midge (also gnats and no see-ums) bites a deer. These insects flourish in mud flats along streams and lakes. During droughts, small water sources used by deer disappear, so deer move to larger streams and ponds to drink, bringing them in contact with the insects.
As I write this column, we are in a rather long drought period, and this means more midges, more deer moving to streams and ponds to drink, and more HD.
This outbreak will end once we get a good frost that eliminates the insects. HD outbreaks are nothing new to West Virginia, as a few deer succumb to this disease every year. But larger outbreaks have occurred in 2017, 2012 and 2007.
The most virulent form of HD can kill a deer in one to three days, but more commonly deer can survive for a week after being bitten. Infected deer appear depressed, have a swollen tongue or eyelids, lose their fear of man, have trouble breathing and bleed from the mouth or nose. Basically, the lining of their digestive tract, from the esophagus to the intestine, erodes and bleeds.
There are various strains of the EHD virus, and some deer can survive the least virulent strains and become immune to the disease. Does can pass this immunity on to their fawns, so one would think that over time an entire region could have deer that would not succumb to HD. However, that is not the case.
The reason is that in recent years, there are various new strains of these viruses coming into our country. Just because a deer is immune to one strain, does not mean it is immune to another strain. For example in 2018, strain EHDV-2 was found in deer in multiple states including West Virginia. Other new strains (EHDV-6 and BTV-1) were also found in Kentucky and West Virginia.
Humans suffer from various viral diseases, and treatment is often difficult. The same is true for HD. Unless you can eliminate all these small flying insects in an entire region, there isn’t much one can do to reduce the impacts of HD.
Obviously, eliminating the insects is not possible.
The good news is that in several years, even in the hardest hit areas, deer numbers will recover.
Dr. Samuel is a retired wildlife professor from WVU. His outdoor columns have appeared, and continue, in Bowhunter magazine and the Whitetail Journal. If you have questions or comments on wildlife and conservation issues, email him at drdave4@comcast.net.
