Ravenna Township, Mich. — Just when it looked like Michigan might dodge another go-round with the deer disease epizootic hemorrhagic disease, the DNR received a call about a dead deer in a watershed in the southeast corner of Muskegon County. The deer, retrieved from Ravenna Township, tested positive for EHD at the Michigan State University Diagnostic Center for Population and Animal Health.
The good news is that there have been no other confirmed cases of EHD.
“So far that’s the only positive deer we’ve tested this year,” Tom Cooley, DNR wildlife biologist and pathologist, told Michigan Outdoor News. “We’ve had some other reports from Muskegon, Allegan, and Berrien counties of dead deer found near water, so the possibility exists (of more EHD), but nothing has been fresh enough to test.”
EHD is caused by a virus that is transmitted through the bite of midges, also called “no-seeums.” The first hard frost usually kills the midges and the disease goes away.
EHD affects wild ruminants and is characterized by its sudden onset and extensive hemorrhages. Deer may suffer extensive internal bleeding, lose their appetite and fear of humans, grow progressively weaker, salivate excessively, and finally become unconscious. Due to a high fever and extensive internal bleeding, infected deer often are found sick or dead along or in bodies of water.
White-tailed deer develop signs of EHD quickly and often die from it in two to 12 days. Deer that are infected with the disease but do not die from it usually develop an immunity, which can be passed from a doe to her fawns. Deer that survive the disease may have brittle or broken hooves with jagged edges.
Biologists and deer hunters alike have been wondering if Michigan was going to have another bout with EHD this fall.
Last year, the state experienced its worst outbreak ever, with EHD being found in 30 counties and killing more than 15,000 animals.
“Last year was an exceptional year. We started getting calls in July and we usually don’t see that until August or September,” Cooley said. “It’s more along those lines this year. This is the time of year you expect to find it.”
Cooley said last year’s outbreak was the result of a perfect storm. The previous winter was mild, so midge larvae, which over-winter in mud flats, had a higher-than-usual survival rate. Also, last summer was unusually hot and dry, which is conducive to elevated midge activity.
“We haven’t had those extended periods of hot weather and we didn’t have drought conditions like we did last year,” Cooley said Sept. 18. “Knock on wood, but this year has been nothing like it was last year.”
Once considered rare in Michigan, EHD has been confirmed in state white-tailed deer nine summers dating back to 1955, including each of the past six years. In addition to this year’s and last year’s outbreaks, the DNR estimates EHD killed at least 300 deer in Cass and St. Joseph counties in 2011; more than 1,000 deer in Ottawa, Allegan, Van Buren, Berrien, Cass, and St. Joseph counties in 2010; 300 to 400 deer in Livingston County in 2009; 150 to 200 deer in Oakland and Macomb counties in 2008; and 50 to 75 deer in Allegan County in 2006. It also was found in 1974 (Iosco, Arenac, Mecosta, Gratiot, and Ingham counties) and 1955 (Lake, Manistee, Muskegon, and Saginaw counties).
Cooley said DNR staff and volunteers will continue to monitor the situation and follow up on reports of dead deer so that the extent of this outbreak can be documented for future use.
According to the DNR, deer infected with EHD are safe to eat. EHD does not affect humans, so edibility of the venison is not affected by this disease. There is no evidence that humans can contract the EHD virus either from the midge or from handling and eating venison.
Anyone discovering multiple dead deer, especially in or near water, or those seeking more information, may contact the local wildlife biologist at the nearest DNR office. Office locations can be found at www.michigan.gov/wildlife under Wildlife Offices.