Special Needs Puppy

A lot has been going on to bring me where I am today with this puppy.
I responded to a woman needing help catching a puppy in a logging area. Weeks of my new friend feeding her and the other dogs there on her way to work. Finally caught her in a catch pen. She had milk. Took her to my vet and no puppies inside, already born. Took her back and we started looking for the babies. Found them but couldn't reach them through the logs.
Talked to the owner and thought all was OK and bought some time. An employee moved some of the logs. Two of the puppies died. A little female is in great condition and now has her shots and wormed and deliced. My friend took the babies to her new vet. Haven't heard of lice on puppies.
The little male he wanted to euthanize as he can't use his back legs. She told him NO and called me. I had her pick him up and meet me at my vets. I don't believe he was injured from the logs being moved.
Little "Scooter" scoots around by pulling himself with his front legs or sits on his hiney and bounces to get around. My vet got together the medicines, gave me instructions after he gave him a very thorough exam.
Scooter eats good, drinks, takes his medicine and plays with his toys and 2 of the other dogs. With his scooting around, he keeps his hiney sore.
Does anyone have any ideas as what I could put on his hiney to protect him but not hinder his movement. He's 5 weeks old and very tiney. In watching him, I doubt he has ever used his legs. His tail is crooked from being broken. My guess is a breach birth breaking the tail and damaging his hips.
Any suggestions would be appreciated. Oh, please don't bother with a reply if it's criticism or recommending I put him down. Your ears would burn from my reply and I'm sure I'd get kicked off the site.
Thanks
Lynn