High protein causing problems is a myth. If the protein is coming from GOOD sources, (i.e. meat) then it's not a problem. If the high protein is coming from grains or vegetables mainly, then it could cause issues because the liver has to overwork to process those kind of proteins. High protein is only an issue if your dog already has liver problems, but even so, some people feed their liver comprised dogs raw food with no problems (I'm not advising this, just saying). I dunno, I mean, I personally feel that the protein levels above, like, 42 percent aren't really entirely necessary. But Acana is 33 percent which isn't really that high? I mean, even the crappier foods contain protein contents that high like Royal Canin 33 and some variates of Purina but their protein is coming from corn, etc.
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.
Btw, I'm also not totally against grains. I think alot won't
hurt them and I feed a few treats (Zuke's, for example) that contain barley, etc. I just think most grains are non beneficial, but some won't hurt either of course.
Check out Orijens White Paper:
http://www.orijen.ca/orijen/ORIJEN_White_Paper.pdf
Some pretty good stuff in there.