I asked the same question over at huntingbbs.com. Answers thus far seem to suggest combination of both terrain and diet. See that thread at:
http://www.huntingbbs.com/forum/topi...rHunting%2ECom
One of the respondents there referred me to deertracking.com. Here's the link to their "Ask the Experts" column, the first note being on unusually long hooves:
http://www.deertracking.com/tr_curre...e.html#experts
Now I've got to research "Hemorrhagic Disease!"