Diane US, I also have a 16 1/2 year old female, Abby, who is now a CRF patient. We lost her brother just 6 weeks ago to very fast onset renal failure. By the time we knew what was happening and began treatment, he did not respond. I digress...
I've learned alot over the last couple of weeks. Abby's levels aren't so bad that we can't try to improve them, so I'm doing everything I can!! Unfortunately, we are also dealing with fibrosarcoma in her, so we're having to be careful what we do for the cancer so as not to further stress the kidneys.
Apple cider vinegar is known to help return levels to normal, so I am adding a few drops to the water bowls each time they are refreshed. It is known to help with a mountain of ailments, so it's worth a shot. I got the raw, unfiltered, organic at the health food store for about $4 for a decent sized bottle. They all (dogs and cats) drink the water just fine with it added. I added an additional water bowl and will actually carry it to her everytime I think about it. She doesn't drink excessively, but will drink 8 out of 10 times that it is presented.
As far as eating goes, the K/D didn't go over real well. I did some research and found Hi-Tor Neo. It is a low sodium/low phosphorus/low protein food. It's higher in fat, so the cats seem to like it more than the K/D. Mine did not. Unfortunately, you can't get a few cans to try. You have to order a case. We have opened 1 can, so I guess I'm stuck with the rest. My cats have always eaten dry, so that's what they're used to. I ordered some Halo dry to see if she will eat some of that, in addition to what intake she does have. It's all about getting them to eat (awaiting its arrival). Halo is extremely high quality food. My vet is in agreement that the quantity of protein is not as important as the quality of protein. If it's a higher quality, the body can process it better. I grabbed a few cans of Wellness to see if she would eat that. She seems to want to lick the gravy off of it, but not really eat the meat. Otherwise, she's pretty much living on tuna. You can buy 'very low sodium' tuna. I've read in several threads that people will feed just a few bites of Fancy Feast everyday just to get them to eat something!! My vet gave us some Nutri Cal, but she won't do that either. I will squeeze some on my finger and just wipe it on her mouth so she has to lick it off. I do that 2-3 times a day.
In addition to reduced appetite, CRF patients tend to have more acid and will throw up alot. Pepcid can be given for that and we're going to have to start that tomorrow after what I found earlier this evening. We had not had the excessive vomiting until just the last couple of days. 1/4 of a 10mg pepcid is the usual dose for cats, but please consult your vet.
There are a couple of supplements available too. My vet gave me some Azodyl to try. The problem with this one is it is capsule form and the capsules need to be given whole for them to be effective. That is not happening at my house!! It did not go well. There is another one that I just learned about and have ordered. Renavast is the name of it. It supports the kidneys and positivity impacts creatinine, bun, phosphorous, hct, and urine specific gravity. It supposedly also give them their appetite back. Again, I have ordered it but have not received it yet. It is a powder that can be easily disguised.
We're doing several other things to help address the cancer. I can't help but think (and hope) that they will also help her kidneys.
She has not required any SubQ fluids yet, but the vet went ahead and did a round on Friday while she was receiving a cancer treatment, just to help take any additional stress off the kidneys.
Hope this helps!!!!! Good luck with your baby!!!