With the tests you have, it does look like Stage 2 CKD. But there can be other reasons why the creatinine is increased such as a cat with a lot of muscle, a cat with pancreatitis, a cat that has had DKA, etc.
I agree with testing urine but it needs to be the very first sample of the day so you can see see whether she "can" concentrate her urine. As the day progresses, urine becomes more dilute especially if she's drinking.
Ask your vet if their lab is associated with IDEXX. IDEXX runs an SDMA test and if the SDMA and the creatinine are elevated, it's a good indicator of CKD.
IF she does have CKD, a few points:
- I absolutely would not start subq fluids now. Subq fluids shouldn't be started until creatinine gets to 300-350 and into Stage best for her to get as much fluid as possible by drinking it or by you adding it to her food.
- Phosphorus, potassium, calcium, and sodium look great. A CBC is needed to see whether she is anemic or not.
- I would try to feed as low P foods as you can find and she does not need a binder at this time.
- I would be sure you have her blood pressure checked every time you go to the vet.
If she were mine, the next time I had labs done, I'd ask for a superchem, CBC, and urinalysis. I would probably repeat labs in a couple months.
In the meantime, I'd start to read as much as I could on Tanya's. I think two things are most critical for longevity in CKD: controlling the phosphorus and anemia so that's where I'd focus my first readings.
There are a lot of moving parts with CKD and somthe more you can read while she's stable, the better.
Pls let me know if you have questions.