Prescription Diet k/d+Mobility Canine is clinically proven to support mobility issues & kidney conditions in dogs to improve their quality of life. Formulated with controlled phosphorus and low sodium to support kidney & heart function. It is clinically proven to help reduce symptoms of chronic kidney disease and supports your dog’s ability to run, climb and jump in as little as 21 days. It supports vitality & alertness in older dogs and contains amino acid profile to support your dog's natural ability to maintain lean muscle.