Supplementing on my own, as I do with the dog, was my first thought. Do you mix yours in with wet food? It's so easy with the dog, drop something that looks remotely like food, that would be anything in his food dish or lying on the ground, LOL, and he eats it.
I will have to check my receipt as we did try an injection but it was not Adequan. It did seem to give slight relief for one day.
Our old girl is quite mobile yet. She can get up and down from her cat stand, though I try to lift her. Yes, she will bop the dog on the head when he gets out of line too, though she won't stand up to the other two cats, silly old thing.
Thanks, I'm going to check out your ideas and Adequan.