I've had the occassion to be around some whitetail "pets" and the most important thing to remember is a buck is a buck and come rut, they are very aggressive and even will fight humans. The few buck I've been around as "pets" were usually nuetered to take that "fight" out of them. As nuetered males they were very calm and of course keep either their antlers in velvet or keep them period depending on what time of year they are fixed. Does on the other hand are very affectionate.

They are able to be house trained and I've been in a few where the deer are like dogs and are very clean otherwise minus the twice a year coat change.

Besides, deer poop isn't messy but urine is you know, urine.