I am hoping and praying that someone can help me here. I have so many questions and my vet is not well-schooled in Mastiff nutrition. He just suggested Royal Canin Giant Breed, but those ingredients look horrible to me. I am a first time EM owner. He is 12 weeks old and around 50 pounds. He's averaging around a .5 pound daily weight gain. The breeder said to put him on Doc Roy's Healthy Bones Calcium Phosphorus supplement until he is around 6 months old. Thoughts on that? Hugo came home from the breeder eating Iams Large breed puppy food and I have not switched him yet because the research is overwhelming and paralyzing me. I am so afraid to make a mistake. Hugo is a bit itchy, so I am thinking about switching him to a food that doesn't have chicken. I thought about a salmon or fish food, but most of the acceptable ones I have come across are grain free...and I have read that is good and then the next article says it's bad for their heart. I am not going to be feeding a raw diet because I also have 6 kids to feed but I do want to give him the best quality dog food I can. If someone said to you: here is what I want....chicken free, 1.2/.8 calcium phosphorus ratio, 23-27% protein and 12-14% fat, what would you say?