Astkatta Snackats - Tuna & Chicken & White Prawn (14g x 4)Suitable For Cats Anti Aging & Bone Health Formula Our Chicken used in our foods is 100% Free Range. Fresh Tuna from Atlantic Ocean non polluted. It provided rich DHA & EPA for Cats. Collagen is the most abundant protein. It is the major component of connective tissues that make up several body parts, including tendons, ligaments, skin and muscles. Collagen has many important functions, including providing skin with structure and strengthening bones.