I wasn't too hip on giving it to Angus when he was having arthritis problems because of the risk of liver damage.
But what I did use was K9 Liquid Health. It really worked wonders for him and was all natural. I just put a little in his food (mixed in some wet food) every morning and I could tell a difference in just a few days. It was a wonder drug for us!
I would definately suggest it before Rimadyl (no side effects).