Have Cat Questions? Ask a Cat Vet Online.
There are a lot of therapies now for cats with renal failure. The first step is usually getting them started on a renal diet. Then flush the kidneys with sub-q fluids. Then you can use medication.
Many cats respond well to these therapies.
So that you can fully understand what's going on, I want you to take a look at this site:
Then let me know if you still have questions.