This Summer in Tennessee our deer herds have greatly suffered from a common disease that seems to be much worse this year. What is Epizootic Hemorrhagic Disease or EHD for short and why does is seem to take more lives this year than in the past? These are the questions I have been asking myself lately so I decided to research and share my findings. It has really hit me close to home as this year my season and hunting tactics have been affected by it.
Epizootic Hemorrhagic Disease is a usually fatal viral disease often confused with Blue Tongue due to the similarities of the two diseases. EHD is caused by a biting fly known as Culicoides or in general terms the common gnat. All documented cases are in late summer and early fall and usually subside after the first frost when the gnats are killed out. EHD is found throughout the United States every year though some years such as this one it can be worse than others.
Deer tend to show signs of the disease within seven days of being bitten. One of the most noticeable things about the disease is how rapidly it progresses. The beginning signs are shorter breathing, loss of appetite, losing their fear of humans and other threatening surroundings. Deer normally filter to water and there they are usually found dead. The reasoning for this is the last stages of the disease, which are rapid heart beat, swelling of the throat and tongue believed to make the deer thirsty. Eight to thirty-six hours later the deer passes into a shock-like state and dies.
Clinically the disease filters into the system and causes extensive hemorrhaging in the organs. No organ seems safe from EHD with the most common affected being the main organs of the heart, lungs, liver, kidneys, spleen and intestinal tract.
It was years before EHD was set apart from other diseases with similar symptoms. In 1955 when several hundred deer in New Jersey and Michigan died off scientists really took notice and tried to get to the bottom of the disease. Until recently, they had not documented it in the areas around home. This year it showed up significantly in Kentucky and Tennessee. The reason to blame for the higher number of outbreaks has not yet been determined. The most likely culprit is the fact we were still seeing 90 degree weather in late bow season when we’ve normally had a frost or two. Around home a couple weeks ago you couldn’t take a drive without smelling the carcasses of deer that had succumbed to the disease. Up to twenty have been found in one area around water. Many people have held off on limiting out due to the die offs. I was never so glad to see a frost this week and hopefully the end to the EHD season for this year.
