JEFFERSON CITY, Mo. (AP) – The Missouri Department of Conservation is asking deer hunters in seven southwest and south-central counties to have any deer they harvest tested for chronic wasting disease.

The department says more than 100 deer and elk in northwest Arkansas tested positive for the disease. The closest infected deer was less than 15 miles from the Missouri border.

So far, no cases of the disease have been confirmed in southern Missouri.

The Missouri counties involved are Barry, Christian, Douglas, McDonald, Ozark, Stone and Taney counties. The testing is free.

Chronic wasting disease causes degeneration of the brain and is always fatal. No vaccine exists.

The department says it’s critical to detect the disease early so it doesn’t become well established.