Hi,
Your story is sadly all too common. The lovely dog at home is all too often expected to act the same way when on his own and with no supervision. Come on people wake up!
Rest assured your vet is giving your dog the best chance possible. There is no surgery or medication that can repair damaged nerves, only time will tell if the damage is permanant or not. If permanant damage has been sustained in all four limbs then there is nothing your vet or you can do I'm afraid. Listen to your vet and follow your heart, you know what your dogs life was like before this incident and you will know whether your dog has an equal quality of life at the end of the day. Your vet will know when the time has elapsed when nerve regeneration would of happened if it's going to.
There is only a point to going to a specialist if there is a return of reflexes, however small.
My thoughts are with you and I wish you the best of luck.
To anyone who allows their dog to roam - your dog only behaves the way he does at home because of the influence you have over him. As soon as he is on his own and free you have no idea what he is capable of, or the dangers he is facing. If you have a dog it is up to you to supervise it and to make sure it is in a safe and secure enviroment when you are not around. Never underestimate your dog - it is after all just a wolf in dogs clothing.