Understanding EHD

Understanding EHD

11-17-2009I have talked to numerous landowners that have asked many questions regarding epizootic hemorrhagic disease (EHD.) The questions arise along the late summer and early fall, around the time peak EHD mortalities occur. The giveaway is usually when the landowner finds numerous dead deer in creeks or standing water. Sometimes it’s because the particular buck they have their eye on suddenly disappears. While it is impossible for us to avoid EHD from claiming the deer on our land, we are very capable of taking precautionary steps that could limit the impacts of EHD on our property.

EHD and blue tongue are different diseases but it is common for many hunters to confuse the two. EHD is spread by a midge, usually around a water source. This midge is a vector, very small insect that carries the EHD virus, usually biting the deer on their underside around their belly. The virus will cause dizziness, the swelling of internal organs, and high fever which causes the deer to seek a water source, which is why many infected deer carcasses are found in water. Another misconception is that EHD is a communicable disease. This is not the case due to the fact that the EHD virus is not airborne and does not infect individuals in this way. That being said, deer that are in concentrated areas such as around feeders can be easily susceptible to EHD because this limits the amount of traveling from deer to deer that the midges have to do in order to find its next victim.

There are a few steps that can be taken to limit the impact of EHD on your property. The first is to limit any supplemental feeding on your property, which concentrates deer, as mentioned above. Also, if your property has any stagnant water with bare muddy banks this is a red flag and needs some habitat modification if possible. When building or modifying a water source on your property, strive to create steeper banks that consist of vegetation up to the water’s edge. There should also be some sort of drainage system allowing water to flow that will keep it from becoming stagnant. Another commonly asked question is “If corn and other types of supplemental feeding concentrate deer, potentially spreading the disease, couldn’t mineral sites?” This is a tricky question but usually the dead deer aren’t found around mineral sites and typically mineral sites don’t concentrate deer as well as corn or other types of bait do. Therefore I won’t hesitate to establish mineral sites. While deer use mineral sites year around they seem to focus more on the mineral sites during the spring and early to middle summer months, not the late summer and early fall when EHD is at its peak.

There is no guarantee that this will limit the virus on your property but that doesn’t mean that we shouldn’t do our best to understand EHD and manipulate the habitat to minimize potential mortalities. Managing your land is a time consuming, yet rewarding endeavor so understanding and identifying any threats to your deer herd should be a primary concern.

Andrew Walters