Firstly, I in no way work for this company! Have posted in here several times about my little 2 year old with elbow dysplasia.
The vet recommend supplements to ease his joints up. We started with Yumove which did precisely sod all.
We started using Itch Pet joint supplements a month ago and the difference is amazing. We're down from giving him metacam either every day or every other day to maybe once a week. He's so much less limpy and has had very few days where he can't put weight on the arm.
It's got green lipped mussel in it which I think is some kind of wonder stuff.
Highly recommended for any cats with joint problems!