Yes! It occurs primarily in the cartilage and connective tissue. So the knobby ends of bones, etc. I know a gal who gives her (large) dog 2 chicken feet a day for the glucosamine/chondroitin and he is completely off of medication and doing great.
Glucosamine is found in bones and bone marrow, chondroitin is found in cartilage.
I feed chicken feet to mine as a treat, they are high in both. I can only get dried ones, I would feed fresh if I could get them. They are available at Chinese markets, as are other types of poultry feet.