You might be able to do subcutaneous fluids and kidney diet. Low phosphorus, low protein. My dog was in same situation but he started eating and drinking again but minimal. Vet says we only have weeks to enjoy him. Good luck. So sorry also. They are like family.
Welcome to the forum...Here is this forums largest thread on kidney disease....It is lengthy, but has valuable information in it........
http://www.medhelp.org/posts/Dogs/4th-stage-renal-failure-in-my-dog/show/425814?page=1