Science Plan* Senior is specially formulated to meet the nutrient and energy needs of dogs who are seven years or older. Balanced nutrition and great taste for older dogs. Promotes healthy skin and shiny coat. Low Phosphorus formula to help maintain healthy kidneys. Science Plan Senior dry has Hill's Superior Antioxidant Formula to help support the immune system. Science Plan Senior dry is enriched with Glucosamine and Chondroitin Sulfate to help senior dogs maintain joint health during aging. You may only purchase a maximum of five bags of this product at one time.