I've got a link from the WDFW site but it is being updated.
http://wdfw.wa.gov/factshts/hairloss.htm
Basicly the deer's immune system gets broken down and the deer get overrun with parasites. Brain, lung, heart, and even skin parasites. They will actually pull their own hair out scratching. It can kill them usually by hypothermia due to loss of hair. I know their is new up to date information from a study the game dept. did with I think University of Washington. I couldn't find anything on the ODFW site. I know it is in both states.