Shoot it.

Albinos are pretty much OK genetically except for the lack of melanin, but piebalds are really screwed up genetically. You don' t want them breeding. They end up getting scoliosis, goat face, and all kinds of other ailments and can pass this on to other deer if they breed with a normal one. Since this is a buck, he can do a lot of breeding damage.

http://www.dnr.state.md.us/wildlife/ddpbald.html

I shot a piebald button buck a few years ago, approx. 75% white. Glad to get him out of the gene pool before he passed it on! I got a full body mount of him, if I can find the pictures I' ll post a few...