Chronic Wasting Disease Confirmed in Farmed Deer Across Three Michigan Counties

ANIMAL HEALTH ALERT

State surveillance testing caught the infections in Calhoun, Kent, and Mackinac counties, reinforcing why routine screening matters even when herds look healthy.

The Michigan Department of Agriculture and Rural Development (MDARD) has confirmed chronic wasting disease (CWD) in farmed white-tailed deer in three counties: a two-and-a-half-year-old deer in Calhoun County, a four-year-old deer in Kent County, and a three-year-old deer in Mackinac County. The first two cases were caught through the state's routine CWD surveillance program for farmed deer, while the Mackinac County case turned up during a trace investigation stemming from the Calhoun County herd.

CWD is a progressive, always-fatal neurological disease affecting cervid species including white-tailed deer, mule deer, elk, and moose. It spreads both directly between animals and indirectly through contaminated environments, and infected animals can look completely healthy for months or years before eventually developing abnormal behavior, progressive weight loss, and physical debilitation.

These detections highlight why it is so vital to perform regular surveillance testing, said State Veterinarian Dr. Nora Wineland, DVM, MS, DACVPM. Early detection allows for a prompt response, which helps limit the exposure of additional animals to this disease.

Why the Trace Investigation Matters

The Mackinac County case is a useful illustration of how CWD response actually works in practice. That deer wasn't found through routine surveillance directly; it was identified because MDARD traced animal movements connected to the already-confirmed Calhoun County herd. That kind of tracing is exactly how a single positive test can uncover a wider chain of exposure before it turns into a larger outbreak, and MDARD says investigations are ongoing to rule out additional exposures among other farmed cervids connected to these herds.

Not Michigan's First Encounter With CWD

CWD in farmed deer facilities is not a new problem for Michigan. Prior to these latest detections, the disease had already been found in farmed cervid herds across several counties, including Kent, Lake, Mecosta, Montcalm, Newaygo, and Osceola. The recurrence in Kent County in particular underscores that surveillance in previously affected areas needs to stay active rather than winding down once an initial detection is resolved.

The Human and Domestic Animal Risk Picture

There have been no reported cases of CWD infection in humans to date. Even so, both the World Health Organization and the U.S. Centers for Disease Control and Prevention recommend against consuming meat from CWD-infected animals, whether by humans or domestic animals, as a precautionary measure while research on transmission risk continues.

What This Means for the Field

Dr. Wineland framed the response as fundamentally collaborative, noting that MDARD's ongoing partnerships with herd owners, hunters, and state and federal partners are just as central to managing CWD as the surveillance testing itself. For veterinarians working with cervid herds, in Michigan or elsewhere, these detections are a timely reminder to stay current on state surveillance requirements and to flag unusual weight loss or behavioral changes in cervid patients promptly, even when an animal otherwise appears to be in good condition.

Source: Michigan Department of Agriculture and Rural Development (MDARD) press release, Aug. 26, 2026. More information: Michigan.gov/CWD and Michigan.gov/MDARD-Cervid.