Responsible dog owners want to know how to keep their dog healthy. A common vet recommended approach is to ensure good nutrition and a proper well-balanced diet may actually prevent many chronic health problems that your dog could develop in old age. So what is the vet recommended dog food that provides your dog the best nutrition? Well, a vet will tell you that there is no single best dog food to buy for your dog, but there is a rule of thumb you can follow that can help you narrow down all of those choices on the market.