I'm so sorry about your kitty! Yes, I've had 2 with kidney failure, it is so very sad. I gave them subcutaneous fluids every day or two for the rest of their lives. I lost Jason to a lung infection and Ashley to just plain old age (18), not to the kidney failure. Push oral fluids as best you can to keep the kidneys working, they're not as efficient any more. Love him as much as you can! Huge hugs to you and your purr-baby :(