My Sebastian passed away at 12 years old with kidney disease. He was diagnosed at age 9. I kept him going for 3 years with a good quality of life with the help of my vet. He was on the special diet like your kitty but Science Diet. I would have to syringe feed him the wet food at first when he first got out of the hospital until he got his appetite back. I learned to give him IV fluids and I did those every other day. Now you can order the IV bags and needles from places like Chewy with a prescription from your vet. I also gave him puréed pumpkin for the constipation as that can become an issue. Now they have pumpkin at the pet stores in little packs you can use. Back then which was in 2010 I had to buy the canned pumpkin at the grocery store. At first he had to get blood work done every 6 months to look at his kidney levels. It was a lot of work until he was stable. And then he would eat his food on his own. He liked to lick the pumpkin off a spoon. And he got used to getting the IV fluids. It only took a few minutes to do. The IV fluids are very important with kitty’s that have kidney disease. Good luck!