You'll probably get better answers in the Health & Diet section. But I believe Acana and Orijen are both made by the same company, but Acana is a little less protein than the Orijen.
High protein has never been known to CAUSE liver or kidney problems, however if the dog has pre-existing conditions, sometimes a lower protein diet is better. I think the reason some people are against higher protein diets are because Yorkies are so prone to liver shunt. Many people feed their Yorkies higher protein diets though and do absolutely great.
From my understanding, in order to consume that much protein... one must also work off the protein, if that makes sense. For example, high-energy dogs should eat higher protein levels than a couch potato. Jackson is a pretty high energy dog and he's also bigger at 12.5lbs so he thrives on the high protein.
Jackson is my picky picky dog and almost 3 weeks ago we started feeding him Nature's Variety Instinct (Duck & Turkey formula) and he LOVES it! He has never, ever, ever, eaten a dry food like this w/o mixing something yummy in. I highly suggest the food. It's grain-free and 35% protein so it's high but not quite as high as the Orijen's and EVO's, etc.
