Hunter1997:
This actually happened to two of my deer last year and both were caused by domestic dogs. The first was a yearling buck. After he hit the fence, he had a large bulge/curvature in his neck and we weren't sure if it was a break or just massive swelling because he was still able to walk. I made every attempt to help him including everything you've been trying. Unfortunately, one day I found him on the ground unable to get up. By that time he lost alot of weight and was isolated from the rest of the herd. I put him down on the spot. If I could do it again I would have ended his pain and suffering much earlier on. As you know, deer are sensitive and easily stressed the way it is, compound that with a severe injury while still in a pen and it is a very hard on the animal.
The second was a doe. She had a broken back but was in a similar situation as your deer. She was unable to walk, stand or even sit up right. I tried the hand feeding and watering for a day or so until the vet could come in. She couldn't even move her right side legs and had no sensitivity in them. I knew there was no hope for this one and I decided to have the vet put her down on the spot. I lost her and the two fawns she was carrying at the time.
You really need to look at your deer's progress in deciding what to do. If there was a chance for improvement then I think by now he would be showing at least some signs of that improvement. If not, you have a tough decision to make. Just trust your gut and do what is right for the animal. If your deer is in with other deer they will sense the injury and pick on him. During rut time, if he is still compromised, the other buck will take advantage of this and he will not be able to defend himself.
As for a solution. Domestic dogs are a real problem. Unfortunately, none of us can be there every second of every day and night to watch your deer. It only takes seconds for a domestic dog to cause a disaster inside your deer pens. After these incidents, I decided to do something to make a safer enviornment for my deer. My farm is made up of six seperate pens inside of one large fenced-in enclosure. One thing I did was I ordered commercial grade black landscape material and I cut it four foot wide and placed it around the outer perimeter at the bottom of the fence. This at least prevents my deer from seeing dogs and wild animals. It helped me tremendously. It helps to give my herd a stronger feeling of security. They may be able to hear the dogs but they can't see them. Believe it or not this has worked for me.
Hope this helps. Good luck.