I've had cats with chronic renal failure and also one w/acute renal failure. Puddy, the one w/chronic renal failure, was given fluids for years and it was difficult for me to know when to have her put to sleep b/c she'd improve and then go downhill again. Like your kitty, she became anemic and that affected her mind causing her to become senile. Someone suggested that I administer B12 shots to her, so I injected the vitamins directly into her bag of fluids and she improved immediately. Peeka, the one w/acute renal failure, went very quickly; after only 3 days I had to have her put to sleep b/c she was jaundiced and suffering. Since your vet said that your kitty can't have fluids, ask if s/he can give your kitty a B12 shot. It may help but, truthfully, I just don't know. I'm so sorry that you're going through this. It's very difficult, I know, but if your vet and/or you feel that your kitty is suffering, then it's time to let her go. It's the last act of kindness that you can do for her and she'll love you for it. Keep the faythe.