I have 2, 6-month old lab puppies. I feed them Purina One large breed puppy food, per the vets orders. They aren't very big for being 6-months old. I was wondering if large breed puppy food stunts there growth so they don't grow to fast? We also have a 3 year old lab and when she was a puppy we just fed her regular puppy food and she grew very fast. I'm wondering if this is why the vet told us to feed them large breed puppy food. I've never gone this route when raising large breed puppies so I'm curious to find out if this is the reason they are growing so slow.