You’ve definitely done some nice work here. Without scrutinizing it in detail, one crit does pop out at me - I happen to be studying deer myself right now, and I know from this and also my study of animals generally that the pose of your deer’s legs needs some work.
First - the overall pose is, in broad terms, fine. But, while plausible, it is not the most likely pose to find a deer in, even when keeping it all in symmetry. The primary problem is that you’ve positioned the front hooves further forward than normal, and the back hooves further back than normal for a relaxed stance, or any other common pose for a deer (that I’ve seen anyway). It makes it look like the deer is trying to straddle something.
Second - the angles of the bones of the legs are generally too straight. A Deer’s front legs tend to have a bit of a knock-knee look to them, meaning that the “knee” (actually the wrist) is closer to the center of the body than the hooves. The same can be said of their back legs, though the term “knock-knee” doesn’t come to mind as readily since they look so different. Basically the hooves of the back leg tend to point slightly out from the body rather than straight ahead (same with the front hooves), and the “knees” (actually the heel) tend to be located more toward the center of the animal than the hooves, sometimes the knees/heels of the back legs seem like they might almost touch each other.
A diagram would be helpful, but I don’t have time for that so I’ll direct you to a few images on the web instead. Hopefully these help to illustrate my points.
http://www.deer-whitetail.com/Pictures/deer/deer-11.jpg
http://khongthe.com/wallpapers/nature/doe-in-the-forest-50220.jpg
One last thing - I’d give the lower portion of the front leg another look (knee/wrist and down), for proportions of features, general sweeps and angles etc.