I'm sorry that you're having to witness the decline of your beloved dog. It's hard to watch, I know. We went through something similar with our lab, who lived to be 14 1/2. Enjoy him while you can; comfort him when he's agitated.
Beth and DH
3 Grown, Non-camping children
Maddie (westie/bichon mix?) and Nash (morkie?)
2012 Aliner Classic
2010 Nissan Pathfinder