Eukanuba Senior Medium Breed dry dog food is complete and balanced nutrition for senior dogs over 7 years old weighing between 24 and 54 lbs. Chondroitin sulfate and 50% more glucosamine (vs. Eukanuba Adult Medium Breed dry dog food) helps keep joints mobile and supports lean muscles in active senior dogs. Optimum levels of fats and carbohydrates fuel their daily activity levels. DHA and antioxidants support healthy brain function in senior dogs and guaranteed antioxidant levels help maintain their natural defenses.