100% Beef Liver - That's it, nothing else, nothing added! The liver stores antioxidants and critical vitamins and minerals, including vitamins A, K, copper, and iron. The liver performs the critical function of moving toxins out of the body on a daily basis, keeping your dog happy and healthy! Organs offer some of the densest sources of nutrients like B vitamins, iron, phosphorus, copper and magnesium and are rich with the most important fat-soluble vitamins, A, D, E and K!