Traditionally, we veterinarians haven't been able to offer much in the way of safe, effective arthritis management for cats. They can't take much aspirin at all due to their lack of a critical liver enzyme to break it down and excrete it, and other NSAIDS like Advil and Aleve are highly toxic.
We have had an injectible form of an NSAID available (Metacam) for cats for a little while, but it can only be given one time, not repeatedly, and the oral form is a bit risky, and not approved for cats.
A couple of new developments have given us new hope, however, for helping arthritic cats: Adequan injection and Hill's Prescription Diet J/D. They both utilize glucosamine chondroitin sulfate for joint support. I have had definite success in the few cats I have used Adequan in. J/D is too new for me to have any feedback yet. It comes in both canned and dry forms.
Adequan is only approved in dogs, but being a nutritional supplement, I am not worried about its use in cats the way I would be with a pharmaceutical (and we use MANY drugs not approved in cats anyway).
According to the Cornell Feline Health Center, "......degenerative joint disease, or arthritis, is common in older cats. Although most arthritic cats don't become overtly lame, they may have difficulty gaining access to litter boxes and food and water dishes, particularly if they have to jump or climb stairs to get to them........Cats with painful arthritis may have difficulty gaining access to a litter box, especially if negotiating stairs is required. Even climbing into the box may be painful for such cats; urinating or defecating in an inappropriate location is the natural result."
If you think your older cat may have arthritis, please schedule an appointment so we can evaluate the situation and decide whether Adequan or J/D might be appropriate. It's easy to learn how to give the injectable treatment, which starts out more frequent and then tapers off to monthly or less, so it's NOT a big deal. And word from Alison's cat Trystan is that J/D canned is exceptionally yummy!