I saw a show on the outdoor channel a couple weeks back where this guy was bow hunting and he walked up on two bucks locked up and both deer were very near death. The guy that was hunting was able to contact the game warden and they were so wore out that the warden was able to approach them and saw off one of the horns. The deer came loose, got up and staggered away with thier tongues hanging out. It was the coolest thing because they were able to save both of these animals.
I've never seen this happen personally, but I have seen a few deer get caught in a fence where thier back legs got between the top two strands of wire when the deer jumped the fence and the wires twist up and snare them. Unfortunately we haven't been able to save any of these animals because they were already dead and half eaten by the time we found them. One of the deer was a buck that was about 120" and 3 1/2 yrs old