I'll just link some of my previous posts for my views and beliefs on food, to give another spectrum.
http://www.yorkietalk.com/forums/3220432-post6.html http://www.yorkietalk.com/forums/3220686-post8.html
Also, want to add that the early research that convinced people of the myth of high protein damaging dog's liver was done on rats which are omnivores and their digestive system works entirely different than dogs which are carnivores. Rat's bodies are not designed to handle high protein the way dogs are. I am not aware of any research on dogs that points to high protein damaging dog's liver. I might be mistaken here, but in addition to using rodents, I believe the source of most of the protein was corn gluten, so it was pretty invalid regarding canines and high protein from meat on two fronts.