My story is about what cartilage did for my little arthritic dog. I hope it is useful.
Last Thanksgiving I removed cartilage and skin leftover from boiling our turkey carcass, and blended it up with some hot water in my Vitamix. It made a kind of meat Jello that I have been adding to my old terrier's grain-free food. She has become like a different dog!
Before I could only walk her about a mile or two because she would get sore and become very slow. But now she can easily walk twice that distance with plenty enough energy left to jump in the car all by herself afterwards. I always used to have to lift her in and out of the car, she couldn't do it on her own.
I just now made the dog another batch of blended up cartilage, this time from a goose. I also hear Vitamin C helps you assimilate collagen into your tissues, I might try giving her some of that, too.