So look for something with less glutens in it.
Just as a side note, I looked up the ingredients for Canidae Platinum (because I used to feed it back when I didn't know squat about dog food so I was curious what's in it) and there are a whole lot of plant-based proteins in it which you may want to avoid if you are, in fact, trying to help your dog's kidneys as well.
The only food I found that really worked for so-called kidney failure dog is raw, but that's just me.
And again, correct me if I'm wrong, but isn't cooked meat really hard on the pancreas as well because the pancreas has to secrete more enzymes in order to digest the cooked meat than it would if the meat was uncooked and still had all its enzymes intact? So it's sort of the same effect that glutens have on kidneys; they have to work twice as hard to process it so it wears out twice as fast.