SIOUX FALLS, S.D. (KELO) — South Dakota Game, Fish & Parks (GFP) has announced that Chronic Wasting Disease (CWD) was recently confirmed in a new area of South Dakota, with the disease turning up in a white-tail deer shot by a hunter in southern Union County, along the Missouri River.

This makes 20 South Dakota counties with confirmed cases of CWD.

GFP says that CWD is a fatal brain disease of deer, elk, and moose caused by an abnormal protein called a prion. Most harvested individuals with CWD will appear healthy and display no clinical signs.