Dogs are carnivores. Their bodies, in all ways, are designed to process and digest diets in high meat protein. It is usually necessary for a dog (or a person for that matter) to drink more water on a nutritionally dense diet.
Here's an article to read regarding dogs and kidney disease. It's not from a vet or anything, but she compiles some good information and links other sources as well. It'll at least give you a jumping off point for doing your own research and deciding for yourself.
http://www.dogaware.com/kidney.html