As summer sets in, a devastating threat can emerge for deer herds. It’s called, Epizootic Hemorrhagic Disease (EHD), and if you’ve ever dealt with its impact, you know it can be absolutely devastating to your local deer herd.Â
EHD is a naturally occurring, often fatal, viral disease primarily affecting white-tailed deer during warmer months, causing significant morbidity and mortality. While common in southern states, major outbreaks have increasingly occurred in northern regions, making it a widespread concern.
Crucially, there are currently no vaccines or direct treatments for EHD in wild deer. This means effective management requires proactive, preventative measures focused on disrupting the disease cycle through environmental or habitat modification.Â
Below, we’ll take a closer look at EHD and introduce EHD-fense, an innovative water treatment system that targets the disease at its source: midge breeding grounds, offering a critical line of defense for deer this summer.
What is EHD?
Epizootic Hemorrhagic Disease (EHD) is caused by two related viruses: Epizootic Hemorrhagic Disease Virus (EHDV) and Bluetongue Virus (BTV), both with multiple serotypes.Â
White-tailed deer are the primary and most severely affected wild ruminants in North America, often succumbing to the disease.Â
Other wild ruminants like mule deer, pronghorn antelope, and elk can be affected, as can domestic livestock, with sheep being particularly susceptible to BTV.
EHD is not transmitted directly between deer. Its spread relies entirely on the biting midge (Culicoides genus), also known as “no-see-ums” or “gnats.”Â
An infected midge acquires the virus from a sick deer and then transmits it to a new, uninfected deer during a subsequent blood meal. The incubation period in deer is typically 5 to 10 days.Â
What’s the difference in EHD and CWD? Read HERE
Signs & Symptoms of EHD
EHD symptoms vary, usually appearing about seven days after exposure. Acute signs include high fever, severe depression, disorientation, and loss of fear of humans.Â
Swelling of the head, neck, tongue (which may appear blue/purple), and eyelids is common. Ulcerations can develop on the tongue and internal organs.Â
The virus damages blood vessels, causing internal hemorrhages and bruising. Affected deer often seek water due to fever and dehydration, so carcasses are frequently found near water sources.
Survivors may develop chronic symptoms like severe hoof abnormalities, leading to lameness and impacting their long-term health.
When Do EHD Outbreaks Occur?
EHD outbreaks are seasonal, peaking in late summer and early fall when midge activity is highest. A hard frost ends transmission by killing adult midges. However, in warmer southern latitudes, midges can be active year-round, leading to continuous viral circulation.
Drought conditions often correlate with outbreaks. During dry spells, deer congregate at dwindling, often stagnant water sources, which are ideal breeding grounds for midges. This concentration of deer and midges drastically increases transmission likelihood and severity.
Outbreak severity depends on factors like midge abundance, viral strain, and herd immunity.Â
Interestingly, northern deer herds, lacking historical exposure, are immunologically “naive” and experience much higher mortality rates (up to 90% in some cases) compared to southern herds with acquired immunity.
These midges prefer shallow, murky, warm and stagnant water sources for breeding. Unfortunately, these water sources are the same preferred options used by your local deer herd.Â
Midge breeding at these locations is worsened during drought, becoming increasingly detrimental for deer congregating at these degregaded water sources, increasing exposure to EHD.
How Can You Fight EHD on Your Property?
To combat EHD, EHD-fense was created as a revolutionary water treatment kit that targets midge breeding environments using aquatic biology to create unfavorable conditions for reproduction.
This natural, biological approach restores water health through three components: Catapult, LiveWater, and D-Muck. The combination transforms degraded water sources into healthy ecosystems where midges struggle to survive.
1. Catapult – Expedites decomposition of complex organic materials (muck, dead organisms, leaves, feces, decaying algae) into simple sugars. This process “sets the table” by providing the necessary food source for beneficial bacteria.
2. LiveWater – Consumes the simple sugars, thrives, reproduces, and actively remediates organics. This improves overall water quality and health, contributing to a balanced aquatic ecosystem.
3. D-Muck – Similar to LiveWater, specifically targets and reduces accumulated sediment and muck by consuming organics. This further enhances water quality and eliminates key midge breeding habitat.
EHD-fense restores microbial balance in aquatic ecosystems by introducing beneficial bacteria and enzymes that outcompete midge-favored conditions.Â
Other Steps to Help Prevent EHD
You should also consider these water source practices to help fight EHD on your hunting property:
- Multiple Water Sources: Distribute smaller ponds or watering holes to spread out deer, reducing congregation and disease transmission risk.
- Pond Design: Design ponds with steeper profiles and encourage shade to deter midges, which prefer shallow, warm water.
- Water Movement: Install pumps or aerators to create water movement, deterring midges and mosquitoes from laying eggs.
- Eliminate Small Stagnant Water: Remove temporary puddles or pools, as even small amounts can be breeding grounds.
- Manage Nutrient Inputs: Control agricultural runoff and mineral supplements near water sources to prevent algae blooms that harm midge predators.
- Encourage Natural Predators: Stock ponds with insect-eating fish and foster a healthy aquatic ecosystem to support predators like dragonflies.
- Larvicide for Drying Ponds: Apply granular larvicide to muddy, drying ponds during droughts to control biting midges.
The EHD-fense product is priced at $229.99 for everything you need to treat a water hole, or small pond. The kit comes packed in a single treatment bucket.Â
One kit treats a 2,500 gallon pond, which is roughly 18 feet in diameter and 1 foot deep.
See more on how to prevent EHD at www.ehd-fense.com.Â
