i have a mastiff and rhodesian ridgeback, and they thrive on it. please let me know if you have large breeds on it, and what they are.
i know, mastiffs are giants, i mean anything over 70 lbs. sorry for not being specific.

Well your Mastiff is not a large breed dog. It's a giant breed dog. The Ridgeback is a large breed dog. It's a good food for some dogs but some can't tollerate it. Too rich.
I personally prefer Canidae.