Feel for you, my old guy is pushing 13 and as a giant he is past life expectancy. He is all there mentally but the body is used up (I can commiserate), needs help on steps and getting on stuff. Falls when he is not concentrating. Can't run, rear legs give out and he drags himself to get to the trouble spot. He forgets he can't just jump a ditch then can't get out. The creek has become a danger zone. He is slowly learning his limitations and will bark to get help when needed. I hope he follows his mate and die peacefully when it is time, I'd hate to put him down. It falls to me, he has not been in vehicle in over ten years nor been to a vet (an hour drive one way) ever. We give all the shots needed.
Sadly there are 2 more not far behind, but the next couple of LDG are here, one set ready the other at 9 months a work in progress.