DD, Perkins, my red cattle dog, is 15 now, with the same issues as Shadow of course, possibly worse. I don't expect him to stand to eat anymore, I tell him to lie down on his bed, then I'll hold his bowl on an angle so he can reach all his feed. He has a Dick Wicks magnetic bed believe it or not, designed for people with arthritis but they also do dog ones. The foam in it is rippled(peaks and valleys) to take pressure off any sore parts, and the cover has magnets sown into it. I throw a dog blanket(cotton) over it to keep it clean and to stop him plucking the fleecy cover.
Outside, sometimes it is scary watching him standing on a bad day. He starts to sink, but it is not back onto the hocks, rather forward from the hocks, in other words his turn of stifle gets deeper as his topline goes down. He has to reposition himself after a while. Poor old dogs, hey? He was having trouble getting up a small half step into the house so yesterday Ian built him a ramp there. LOL. We already have a big one onto the porch for the dogs, now another, and I just haven't got used to it yet !
I nearly trip, or I jar myself because I am expecting to step down. At least he manages better though.
X rays taken here when dogs were say just 8 or 9 showed noticeable spondolytis, so I hate to think what they'd be like in their old age. Incidentally, re the Cartrophen, I've used it for two dogs, one it worked for, the other it didn't.