Nutrisource Large Breed Puppy food is the only dry dog food I give my puppies. There are some grain free dog food brands that the FDA has speculated may be contributing to heart disease, therefore I avoid all grain free food. Growing puppies need specific food tailored to their breed. Large breed food is recommended which helps the puppy grow at a natural rate which allows the bones and joints to develop properly. This is key to prevention of bone and joint developmental orthopedic disease (DOD). Growing too quickly is not healthy for large breed puppies. While it is tempting to think that large breed puppies need more calcium to support healthy bone growth, studies have linked high levels of calcium and phosphorus to DOD. Limiting the intake of calcium, phosphorus, and vitamin D helps reduce the risk of DOD in puppies, and limiting the number of calories in their food helps to slow growth rates. Medium or Small breed food is tailored to help your puppy grow at a a faster rate which requires a higher caloric content to their food. Dog foods formulated for small to medium breed dogs increase the calories without increasing the amount of food in a serving. This is done by maintaining a higher fat to protein ratio in the dog food recipe. Although my puppies are not large breed, their genetics are from large breed dogs like the golden retriever, labrador retriever and standard poodle. Therefore I only recommend large breed puppy food.