I fed raw for many years. But 40 years into the raw food, not one single study has shown it to be beneficial over high-quality kibble. Not one. In fact, the opposite is true. And it makes me sad, because I really felt it was best. But I am a science-based believer. Doesn't mean I don't do and believe in things that cannot be proven.. but I know the difference.
With a sick dog, many if not most of the actual veterinary nutritionist experts say that any question of immune issues is the one place they do not recommend raw meat diet. Especially since you are not sure what else may be going on, switching to raw meat seems an unnecessary risk. (See below RESEARCH articles.)
Even so, high-quality raw meat in a diet for kidney disease is not high protein amount. Going moderate at his stage can, at the very least, make him feel better
So yeah, if you have given up, just want to feed the dog something he likes, go for it. But do it knowing that when you up his protein, you probably lower his life expectancy and he'll feel sicker.
If you just want to incorporate raw, talk to a nutritionist online who can help you develop a balanced raw diet which will be lower protein, but GOOD protein (chicken and other poultry preferred) so that you aren't adding in too much, and not upping phosphorus. This is a good article, not a fanatic on either end :), not a vet but good links and info:
Unfortunately, the research against raw is piling up. Animals ate raw in the wild because they have no stoves or opposing thumbs. Canids kept in captivity live much longer. I always shake my head about "in the wild" comments.
However, we do our pets no favor by making dramatic changes in established feeding practices based on unsubstantiated theories or hunches without adequate evidence. As far as raw diets are concerned the theory behind them is weak, and there is currently little evidence concerning their health effects. More work will need to be done before it makes sense to claim these diets have benefits which outweigh their risks. The argument that we should be feeding these diets to our dogs because they are fundamentally wolves inside is not supported by the existing evidence, and it is not a sound reason to experiment with our pets’ health.<< Skeptvet
A small study, but important one awaiting a larger sampling:
As for raw, I wish any research ... legit and peer-reviewed... supported it. They don't.
For the raw defenders... here is a lot of the usual responses and why the opinions still aren't facts: