Barkworthies, 2 Pack, 12", Chicken Wrapped Collagen Natural Dog Chews. Barkworthies Collagen Sticks are getting a boost, now available wrapped with real chicken! These Daily Health Boost Collagen Sticks are made up of 60% collagen, collagen being the #1 ingredient. Collagen is a naturally occurring protein and is one of the key components of all connective tissue. It promotes mobility and flexibility, helps relieve joint pain and stiffness, supports healthy skin and coat, and boosts digestive health. These all-natural long-lasting chews make for a tasty treat that is good for your dog both inside and out.