I really wish you both the best. I also have a cat right now with kidney problems. He has a stone (that's what we call it here anyway) in one of them and it's something that he will have for a while. The only thing to do now is give the necessary food and make sure he does the things he's supposed to do.
The food thing is hard, I know. My Max is very hard to please, but my vet says that they will eat when they're hungry. I know that this isn't written in stone, but if they're somewhat healthy, they probably won't starve themselves on purpose. When that happens it's probably due to not feeling well.
Anyway, there are a brand that vets sells, that is very tasty if they stop eating all together. Hill's a/d I think. I forced fed my Max this when he didn't eat and was feeling sick. That triggered his appetite and then he ate regular food. The vet also mentioned that they might like some Omega-3 oil on their food. That's a special oil for cats. Didn't work here though lol, but you never know.
I do understand that the food is extremely important for their kidneys, so I hope that it all goes well with that.
My very best thoughts to you both!
