State wildlife officials still haven’t confirmed what malady has killed almost 200 whitetail deer near Frenchtown, but they suspect it’s a disease that’s common throughout the Great Plains.
“We’ve not found it out here before, and that’s why we’re really taking a close look at it,” Montana Fish, Wildlife and Parks wildlife lab supervisor Neil Anderson said of epizootic hemorrhagic disease, the top suspect in the die-off. “It’s usually found east of the Rocky Mountains. We haven’t seen a (Montana) case west of the Rocky Mountain Front since records started in the 1990s.”
Residents and river floaters started seeing sick or dead whitetails along the Clark Fork River between Harpers Bridge and Erskine Fishing Access Site about two weeks ago. The numbers suddenly increased this week. As of Friday, at least 175 carcasses have been reported, although some incidents appear to be natural deaths unrelated to the Frenchtown die-off.
It will take at least another 10 days to positively identify what has killed the deer, Anderson said Friday. There is no indication the animals were poisoned or affected by something unnatural in the environment, but the lab is not ready to rule out anything for certain.
If it is EHD, Missoula County would join an affected area that runs from the Canadian border around Havre southeast to Florida. EHD has also been reported in some counties in Idaho, as well as parts of Washington, Oregon, California, Nevada and Colorado.
“EHD seems to be an annual event,” FWP Region 7 wildlife manager John Ensign said from Miles City. “We typically get reports at this time of year of dead and dying deer. There tends to be a hot spot here and a hot spot there, clean across the region. Every five to seven years, we get an outbreak that’s more widespread and extensive.”
Ensign said because afflicted deer usually seek water shortly before dying, that makes them more noticeable.
“It becomes fairly obvious and that’s alarming for folks – the concentration of dead critters along rivers,” Ensign said. “Does that mean there’s a bunch back in the hills? No, they tend to concentrate down there by the water, so it looks worse than it is.”
Deer get EHD from biting midges or gnats that live in river corridors. The virus involved only spreads from insect to susceptible mammal. Infected deer can’t spread the disease to other deer or livestock, and the virus has no effect on humans. There is no cure or treatment for EHD, and no management tool to prevent its outbreak or spread.
However, researchers at the Southeastern Cooperative Wildlife Disease Study in Georgia, which provides baseline EHD information to veterinarians nationwide, say it has limited environmental impact.
“Although die-offs of whitetails due to hemorrhagic disease often cause alarm, past experiences have shown that mortality will not decimate local deer populations and that the outbreak will be curtailed by the onset of cold weather,” the SCWD report stated. It also noted that cattle often have antibodies to the EHD virus but only a small percentage get sick. It does not affect domestic sheep, although a related disease commonly known as blue tongue can be dangerous to both sheep and wild antelope.
An outbreak of EHD this fall in North Dakota has prompted wildlife officials there to suspend sales of more than 1,000 antlerless deer tags in the southwest part of the state. In 2011, the state offered refunds to 13,000 tag holders in that region after EDH caused “moderate to significant whitetail deer losses,” according to North Dakota Game and Fish officials.
The carcasses along the Clark Fork don’t pose any health threat as they decompose, although they will smell bad for a while. FWP Region 2 bear manager Jamie Jonkel said he anticipated some bears would come to scavenge the bodies, but he hadn’t had any reports of conflicts there as of Friday afternoon.
Not all deer that catch EHD die from it. In Miles City, Ensign said he occasionally meets a hunter who’s shot a deer with damaged hooves that are a symptom of past EHD infection.
“There’s nothing wrong with the meat, and it doesn’t affect humans,” Ensign said. “I’ve been here almost 30 years, and it’s a regular occurrence. You’ve got to wait for the first frost. That kills the gnats and things slow down.”