DNR: Wasting disease shifted in Michigan’s deer herd

John Barnes
Special to The Detroit News

A deadly disease that threatens to decimate Michigan’s whitetail deer population has shifted northwest from the Lansing area, some 100 miles, new test results show.

All but one of the new cases of chronic wasting disease in the just-ended 2017 firearm season were discovered in free-ranging deer killed in Montcalm and Kent counties, 40 total, according to the Department of Natural Resources. One case was found in nearby Mecosta County.

That is far more than nine so-called “zombie” whitetails identified in Ingham and Clinton counties the two previous years. It suggests the always-fatal disease has percolated in Michigan more extensively than previously known.

“It's clear that Montcalm and Kent have had CWD longer than Ingham and Clinton where we have identified it,” said Chad Stewart, the DNR’s deer specialist. “What we don’t know is the space between (the outbreaks).”

In all, 50 cases have now been identified in Michigan since the first emaciated, confused deer was killed by police east of Lansing in 2015. Three others were found from two penned deer farms or ranches in Mecosta County.

Chronic wasting disease is unrecognizable — yet still infectious — in diseased deer in early stages. Its end-stage leaves deer emaciated, listless, drooling and unafraid of humans. Deformed proteins literally eat holes in the animal’s brain. Infectious disease experts caution against eating infected venison.

The 2017 deer hunting season ended Monday. On Thursday, the state will begin two brief limited hunting seasons to see if wildlife experts can connect the dots between the two outbreaks.

The special hunts will run through Sunday and Jan. 11-14 in northern Ionia County and eastern Montcalm County in 14 townships, some 500 square miles. Any deer killed must undergo testing for chronic wasting disease.

“I'm not expecting a lot of deer to be harvested, but if we are able to identify a CWD-positive animal in this area, then it will provide valuable information to inform our management decisions going into next hunting season,” Stewart said.

The DNR will soon begin capturing and collaring white-tailed deer in the western Upper Peninsula as part of a multi-year study to review herd movement as well as detect if the disease is present.

“Limiting the spread of CWD is difficult, but even more so here in the U.P. where winter severity results in increased deer movements and yarding behavior that concentrates animals,” said Terry Minzey, DNR U.P. regional wildlife supervisor, in a statement.

A special task force, meanwhile, is expected to give recommendations Jan. 11 to the state Natural Resources Commission on how to slow the disease that has devastated herds from Wisconsin to Colorado.

Bans by the state against baiting and feeding in core disease areas expanded Monday.

“We want to see a serious discussion about baiting and feeding in disease areas where we want to prevent the spread of the disease,” said Amy Trotter, deputy director of Michigan United Conservation Clubs, the state’s largest such organization.

Michigan United Conservation Clubs has opposed baiting and feeding in the past, saying it congregates deer and assists the spread of infectious disease.

“From our perspective, these numbers appear to indicate we have a new epicenter,” Trotter said of recent mandatory testing of hunted deer in high-concern areas. “What we need to know more is, Are we all linked up here? Mid-Michigan may be on the front edge of what direction it is moving.”

At this point, the best hope is to contain — not eradicate — the disease, she said.

“They are literally the walking dead,” Trotter said.

Michigan’s known prevalence of the disease is still small but has the potential to expand greatly. In early stages, deer show no symptoms as they contaminate other deer through contact or soil infected for years from urine or feces.

Prior to the recent hunting season, less than one in 1,000 white-tails tested positive since the first known free-ranging Michigan case in 2015, according to the DNR.

By contrast, however, one in 100 deer tested positive in Montcalm County during the just-passed hunting season, 32. About one in 60 deer tested positive in more-limited testing in neighboring Kent County.

A few were identified outside mandatory testing areas. Few showed symptoms, perhaps indicating the disease is in its early stages.

Concerns about the disease’s movement rose after a free-ranging deer, a 1.5-year-old buck, was identified in Montcalm County’s Sidney Township in late October. An infected 6-year-old pregnant doe was killed weeks earlier in neighboring Montcalm Township during the youth hunt. Mandatory DNR testing of deer taken there and in parts of Mecosta and Kent were initiated.

Deer hunting is an estimated $2.3 billion hunting industry in Michigan, with nearly 600,000 hunters participating in the November firearm season alone.