Compared to other pets, dogs are unique in their size variation. As you can imagine, a 150-pound Great Dane will have different health and nutritional needs than a 3-pound Teacup Yorkshire Terrier (that’s a 50 times difference in size!).
Large and giant breed dogs (pups who are over 50 pounds at their adult weight) need a diet formulated for their unique metabolism (they have a slower metabolism than small dogs), longer digestive tract length, larger stomach size, and bone/joint health requirements.
Additionally, growing large breed puppies need a diet formulated just for them. They do a lot more growing than smaller pups do, and excesses of certain nutrients during puppyhood can lead to bone development problems.