My Chocy (100 lbs) was diagnosed with arthritus a few months ago. I knew from past experiences to always give my dogs Glucosamine to avoid joint issues. But apparantly it wasn't enough. The vet gave us Phycox, they are chews and he gets one twice a day. Within a week his limp got better, within a month cleared up. His mom, Dixie was the next to develop it, she started the Phycox and all is well already. I now give it to all my dogs, as a preventative. I don't know the strength I don't believe it comes in different strengths. But I have talked to other vets about it and they also swear by the stuff. Google it, it is amazing.