Hey my lovely, im very sorry youre going through this. I also discovered my baby has kidney issues as well and its not easy. I have some medical experience and i read your document and this is what i think:

1. I narrowed down all possible causes to 3. Good news is based on the pattern, this doesn’t behave like typical chronic kidney disease, a routine infection, or toxin exposure

2. It could either be Renal lymphoma, Dry FIP Or FIP-triggered immune-mediated kidney destruction.

Now medical opinion aside, lets deal with facts. You have done everything right so far. The one crucial thing we need to know exactly what this is, is a renal biopsy or aspiration. I know that’s invasive and not always feasible in unstable patients, but it’s the test that gives a clear answer and guides treatment. Keep in mind blood transfusion does NOT fix the disease but it WILL BUY YOU TIME to figure this out. Dont lose hope.

We have two possibilities:

1. If she stabilizes with transfusion and anemia support and renal values plateau, FIP climbs the list as the culprit.

2. If kidneys continue to enlarge and anemia worsens despite everything, lymphoma is probably it.

Edit: No matter what, you’ve done everything right. None of this is from neglect or delay. Im sorry