Today hopefully is a positive turning point with Echo. He actually walked on all fours to get into the back yard to relive himself and walked back in. Those back legs are still a little unsteady but he is making improvements and we hope he has no setbacks.
I believe I now know how he hurt himself. A few days before his legs went out totally on him he was going out into the back yard and his rear feet slipped out from under him on the paver's that make up the sidewalk. He bounded right back up and did not appear injured but that must have done it and it took 2-3 days to manifest itself.
We are still trying to keep him resting as much as possible but his recovery is noticeably improving. I don't think he is out of the woods just yet however.