Adult Dog Food and TreatsKnow what's best for your dog. Choose among the many varieties of adult dog food if you have a grown up dog living at home. Adult dogs have different nutritional needs than puppies, so you need dog food that is formulated to provide your dog with the essential vitamins and minerals to keep it healthy and strong. Shopping for adult dog food is easy at PetStore.com. With easy clicks, you can immediately add any item to your cart.