Hi
A couple of things. My Fred had CRF for 6 years---and never progressed until he was 19 years old and only then did I give him fluids.
BUT BIG RED FLAG. My damn vet never said--OH WE SHOULD FIRST MAKE SURE THAT YOUR CAT DOES NOT HAVE UNDERLYING HEART DISEASE before we start pumping him with fluids. Asshole. My cat had an already diagnosed heart murmur. I had no clue this was a concern--but in an old cat--like you're, it is.
If you can afford it, you should really get an ultrasounds--echocardiogram to make sure your kitty does not have underlying cardiac hypertrophicmyopathy (HCM). Otherwise by pumping in all those fluids you can induce heart failure (fluids in the lungs and the heart gives out trying to pump them out.) This is what happened to Fred. And my damn vet had me giving 100 ml every single day--without building up This is a hugely excessive amount---and Fred's kidney values were not even all that bad.
So my words of advice because this DEFINITELY sped up Fred's demise...is check for the HCM with an echo i you can. If you cannot afford it, then go much more slowly with these fluids---try to figure out how LITTLE you can give him and still have him feel good. The fluids are a HUGE strain on the heart. Just like insulin, less is more. It's good that you are doing it several times a day instead of one giant wallop but if your cat were mine, I would drop the doses way down and see how he does--even 20-30ml a day....If I had done that with Fred, his heart could have handle THAT amount.
Also look for early signs o cardiac heart failure---and my vet never believed me when I told him of these early on--he had no clue what they were and denied it was the lfuids--I KNEW they were becuase 1) I knew my Fred and 2) it happened immediately after fluids: his legs would collapsed, he would go to the litter box and collapse and could not stand up or stay up or walk. Just temporarily, but it was something with the vagus nerve or something but def. a reaction to the fluids. Also, very slight open-mouth breathing--as it got worse--fluids in the lungs.
But don't let it get to this point, just be very conservative about pumping him up with them. My Fred got a ton better AT FIRST as well so I was fooled into thinking that 100ml in a 19 year old skinny cat was OK...it wasn't. I should have gone very low and slow and barely progressed.
2. Food. Dont give hte renal food. Give all the good high protein, low carb, no grain food we all feed our Db cats: Wellness, Evo, Nature's Variety, Merrick, BG, etc. Only canned.
3. Give a phosphorus binder with the food...as described above. I switched between the two main types--so not to deplete Fred of certain other minerals by over using one. I'd use one type for breakfast, one type for dinnier. IT's easy and cheap and order them online.
4. USE SMALL NEEDLEs..The vets use 18 gauge which is a spear that hurts the kitty...some people go to 22 which is still massive. I kept experimenting in sizes until I got to 25 and 26 gauge needles for the fluids. These are teeny and will make kitty enjoy the experience and also NOT create that lump because the fluid goes in a bit slower. IT's an extra 10 minutes, not much, but worth it for the comfort of your kitty. The only diff. betw. the 25 and 26 is the length. The 26 is quite short needle so you have to keep your hand on it while the fluids are going in--if he shifts around it can pop out. Otherwise the 25 gauge are longer and you don't have to worry about that as much, but they are still very very thin and make the experience pleasant.
I would put my fred on the kitty donut bed on my couch. Put a towel on him, then a heating pad on that. I had the fluids hung up on a picture hook by my couch and when he was nice and warm, I would then put the needle in and then place the towel and heading pad back on top of him, often with my hand under it as well so I could test the heat and since I used the 26 g, hold the needle in place. Fred purred the entire time.
Just be careful of those fluids, please do not fatigue his heart...Vets don't often think of this and I learned the hard way.
By the way, after the heart failure, Fred stopped the fluids...another long story but he lived for 10 more months--on NO fluids, and never on renal food. The only heart drug he was on was Plavix. I made them take him off the 3 others they prescribed when after the 2nd dose he didn't move for 10 hours straight. My poor baby.
5. Also Pepcid A/C 10mg tablets. I gave Fred 1/4 tablet (of the 10mg, so 2.5 mg) only once a day in the morning. This was a safe amount and totally removed all nausea. I simply mixed the crushed pill (buy a bill crusher too) in a little water and put that on his food.