Our Zssential Formula provides a combination of protein sources across the board to maximize the nutritional benefits that each type of protein has to offer. It brings together red meat, poultry, and fish to create the most complete food for your dog. In addition to a wide variety of vitamins and minerals, Zssential also provides a nutritionally correct ratio of fruits and vegetables that rounds out the recipe with powerful antioxidants and fiber-rich low-glycemic carbohydrates. Zignature Zssential Formula - Learned from Nature, Crafted to Perfection.