Collagen is found in skin and connective tissues like joints, tendons, cartilage and ligaments. Collagen controls the strength of hair, skin, bones, nails and teeth. Normally collagen is produced within the body, but as our dogs (and us!) age it depletes. Good news, it can be replaced through supplementation! The earlier you supplement with collagen, the more likely you will be to avoid problems. There are no side effects of using quality collagen supplements. It helps maintain and rebuild torn ligaments and cartilage, reduce joint pain, improve joint and skin elasticity and more.  Hydrolyzed fish collagen is a powdered supplement that can easily be added to a dog's food.