After doing a fair share of research on types of dog food for large/giant breed dogs. There are some key things to look for while comparing food to look for.
1. 24% - 28% Protien: The closer to 24% the better
2. 1.2% - 1.5% calcium: The closer to 1.2% the better
These two are to limit the speed that your puppy grows which helps reduce joint issue that may occur later in life. From what I have read for the most part the dogs genetics have more to do with the size then over feeding them, as long as they are feed properly. So increasing protien and calcium only increase the speed that you puppy will get to full size, not the end size of the dog.
3. Avoid fillers in pet food at all cost, Wheat, Corn and Soy.
4. Look for food with multiple sources of protien in the 1st 5 ingredients. Sources examples (Lamb, Chicken, Fish,....)
5. When you are looking at sources of protiens, a listed meat is listed according to its predehydrated weighted, where as a protien source listed as a meal is dehydrated already. So if the list has Lamb as 1st ingredient after it has been dehydrated it would actually probably be the 6th or 7th ingredient.
6.Look for Glucosomine this is a must for large/giant breed puppies (chicken is a natural sources for this)
7. Look for DHA this helps with eye and brain development (ocean run fish is a natural sources for this)
As far as making sure you are feeding enough this is what I have done and has worked well. I feed my puppy 3-4x a day all she will eat for 5 minutes then take away her food. When you look at your dog to see if its to thin is if you can see the outline of the backbone, you should be able to see the last few ribs. This has worked for me.
