Yes. Both glucosamine and chondroitin are found naturally in the body. Glucosamine is needed to produce glycosaminoglycan, a molecule used in the formation and repair of cartilage, and chondroitin gives cartilage elasticity and it prevents cartilage destruction. Production of glucosamine slows with age. So while your younger dog may not have joint issues now, additional glucosamine and chondroitin will not cause any problems, and may help your dog avoid a joint problem later in life.