Crow’s Nest: Dead Deer

September 18, 2018

By Daniel Barringer, Preserve Manager.

By now if you’ve driven through this area with the windows open, you know there’s a problem. All over, you can smell the stench of decaying animals. From Morgantown to Pottstown to Chester Springs deer are dying by the dozens, if not in much greater numbers.

Pennsylvania Game Commission biologists are testing the dead deer that are found fresh (by the time they smell, they aren’t useful for testing). The National Park Service has taken samples in Hopewell Furnace National Historic Site to submit to a laboratory. We have a suspicion that these deer are dying from Epizootic Hemorrhagic Disease, a virus that is spread by midges that are not native to Pennsylvania but that blow in periodically. Outbreaks don’t happen often enough for deer that exhibit some resistance to pass that trait on to subsequent generations, so this disease has a very high mortality rate for deer.

Here’s a link to an overview of the disease on the Pennsylvania Game Commission website: https://www.pgc.pa.gov/Wildlife/Wildlife-RelatedDiseases/Pages/EpizooticHemorrhagicDisease.aspx

The midges breed in mud so the disease is sometimes worst in dry years, when deer congregate near the little remaining surface water and are exposed to them in the few remaining mud flats. This year when it seems we have had more rainfall than ever, everything is mud; everywhere is habitat for these small biting flies.

I’ve heard recent reports that this disease was already in our area last year, causing a few deer deaths. This year it is widespread. There is no vaccine that will inoculate deer. There is no cure once infected, though some exposed deer will survive. The disease will run its course until the vector—the midges—are killed by frost in a few more weeks. Overall, deer populations will rebound  quickly in the next couple years.

Humans are reportedly not affected by the virus, though people who hunt should avoid exposure to outwardly sick deer as there could be secondary pathogens to which they could be exposed. Deer exhibit symptoms within seven days of exposure, according to the PA Game Commission, and succumb 8 to 36 hours after that.

It’s simply awful, but there doesn’t seem to be much we can do. We’re still gathering data, and await the results of the laboratory tests, and will share additional information as we gain it.