Collagen is the most abundant protein in the dog's body and is needed for the new formation of tissue around the joint, such as e.g. tendons, muscle attachments and ligaments. Collagen cooperates with chondroitin for the new formation of joint cartilage. Working Dog Collagen also contains MSM and hyaluronic acid which maintain the lubricating function of the synovial fluid and improve the supply of nutrients into the joint.