Thank you all for your kind welcome. My cat is still at the vet's receiving IV treatment, but I did see her yesterday (saturday) and she looked much better, she was eating and that really cheered up since I haven't seen her eat since last Wednesday. It was herself again and although she has this disease, I'm happy to see her that well. I'm supposed to call the vet in a while to see how she is. She's no longer dehydrated, as the vet showed me with the pulling skin trick, that was also very good to see. Tomorrow (monday) at noon I'm bringing her home. I already bought her food Hill's K/D (dry) and plan to buy the wet version as well. That's all he prescribed, and of course, water at all times, which she has always had. I'll see how she behaves and whether she pees a lot, which I didn't see while she was still here.
Her creatinine was at 4.7 and her BUN was 60, which the vet told me could be that high due to dehydration. No, he did not do urinalysis.
I have a question about her feeding though: I know Hill's K/D is low in protein. Is that okay? Do I need to also feed her meat, chicken to compensate this low intake of protein?
I hope I can enjoy her company for many years as well, I'll do everything I can to make her feel healthy and comfy.