Do you have blood panel numbers for
Gucci? BUN, creatinine, phosphorus
and calcium would be useful
to know. Post them if you have them.
Also, have you read my article on diet and CKF dogs? It's here if you want to have a read:
http://www.infobarrel.com/How_Diet_Affects_Dogs_with_Chronic_Kidney_Disease
What are you feeding him now? Is it tinned, dry or homemade? What treats do you give him? Have you tried any supplements such as Azodyl, pure salmon oil or probiotics?