This is our 30% protein super stamina formula for dogs that need more energy to âgo the extra mileâ or have difficulty maintaining weight. Its 20% clarified chicken fat is easily and quickly metabolized. Its carbohydrates are top quality, easily digested whole grains that provide long-term energy. PreciseÂ® Endurance FormulaÂ® is also great for feeding during the third trimester of pregnancy and nursing. The added Ester-CÂ® brand of Vitamin C strengthens the immune system, and helps working dogs recover their mobility more quickly. Its chelated minerals and lecithin provide the needed trace elements and essential fatty acids crucial to complete nutrition.