Large numbers of whitetails have died across the Northern Plains from EHD (epizootic hemorrhagic disease). EHD is a virus spread through biting midges that causes severe internal bleeding usually killing the animal within weeks. Mule deer, elk, and bighorn sheep are susceptible to EHD. Humans can't be infected by EHD.
http://news.yahoo.com/northern-plains-hit-hard-deer-killing-disease-153148327.html
http://news.yahoo.com/northern-plains-hit-hard-deer-killing-disease-153148327.html