My kitty Taz, that I told you in your other thread looks like Honey, had CRF. His came on fast and furious. Although, he had some other kidney issues that I believe were related (even though the vet didn't think so). I had to do the sub-Q fluids. And after being here on Pet Talk and hearing others talk about it, I swore I'd NEVER be able to do that to my cat. But you know what....I did it! My boyfriend helped hold him and it was really very simple. The only time I missed was the very last time we did it. I began the drip and it went all over the place because I had stuck the needle all the way through.
He hardly flinched when I put the needle in (and they are not small).
It's amazing what you can do when it's necessary. Otherwise, you would need to pay the vet to have it done as often as she needs it, which would be expensive.

Don't be discouraged by the sub-Q fluids not working for someone else's cat. If you could see all the stories of kitties that it DID work for.....it's amazing. I know there are several people on here who had cats with Renal Failure who lived for several years. You just never know how quickly it can happen. And I know if either of my other two cats got it, I'd do whatever I had to in order to keep them comfortable and with me for as long as possible.

Good luck to you and Honey.