Looking for a new large breed puppy food (live in Alberta, Canada). I am sensing he is sensitive to chicken and I am now well aware that the calcium / phophorus ratio is very important among other important ingredients (lower fat as well as lower protein than a lot of puppy foods). Any recommendations, I am already concerned he is growing to fast and would like to do my best from here on forward to do the best for him. Firstmate? Solid Gold? Holistic Select? TOW? Argh so many!!!