The #1 ingredient of this formula is Tuna, which is hypoallergenic protein. It provides high protein and promotes muscles growth. In addition, it supports healthy skin and shiny coat. Also, level of cholesterol in blood arteries is lowered and heart system is supported. Since brown rice is the source of carbohydrate, it produces high energy and fiber. Moreover, this formula also includes natural antioxidant from Rosemary and Vitamin E. You can be confident that your beloved cats will be specially taken care of by SmartHeart Gold.