Good catch on the +4. The 47 is probably from the depot of the insulin from the 3 unit dose.
I won't be around too much longer today, as I have to go to work.
Feed The Forties is what we say, so make sure she eats some food now, not too much, just a little, so she doesn't get too full. You may have to test and feed small meals for several hours and you don't want her refusing to eat because she's full if you need her to eat.
Did you get more test strips? Now that she's at 47, you can't exactly go running to the pharmacy. Do you have someone who could go buy them for you? As soon as she gets into higher number (like a lot higher), go buy test strips! Don't forget.
I think you are getting her dose to a safer place. When you were on 4 units and not testing, that was scaring me.
Normally, we do the dose adjustments by 1/4 units. How much room is between those 1 unit lines on your syringes?
You were able to measure 1/2 unit, do you think you could figure out how to measure 1/4 and 3/4 units using those syringes? I would practice that when you can. For right now, your new regular dose is 2.5 units, but sometime soon, you may need to adjust the dose by 0.25.
I don't have any answers about the medical questions and your concerns about the surgery. You could try posting on health about that, but I think it's mainly up to you and your vet. The surgery is needed, but is it needed right now?
I thought I read somewhere that she had some breathing issues about 6 months ago. What was that all about?
Maybe, my memory fails me and it was a differnt cat. If it was Noni, make sure your vet knows about that, too.
I hope you have a good day. I would feed and test again in 30 minutes.
but i'm learning ...