hi Anna!
There is an odd phenomenon that happens with insulin in diabetic cats - sometimes too much insulin can cause high numbers. It can look just like not-enough insulin. The cat's body is fighting to sustain itself against the insulin and is releasing stored sugars and hormones to keep the cat's blood sugar up.
Looking at what's happened in the past 10 days or so:
2/24 Bailey didn't have any dry food - i think his first day without any.
2/25 amps was 70 - AWESOME! looks like his body was responding to the dry food carbs going away. You waited one hour, then gave 1unit of insulin.
2/25 pmps was 520 - he bounced. you went back to his previous dose of 2.25u. The bounce was caused by his liver reacting to the lower numbers that he wasn't used to. it didn't mean he needed more insulin. See the description below of that.
2/26 amps 394, dose increased to 2.75
now he's increased to 3.25 and he's basically been high since 2/25.
Here is a post explaining why we sometimes see high numbers that are not caused by a cat needing more insulin:
New Dose Wonkiness and Bouncing. The TR Protocol is pretty specific on how long we wait inbetween dose increases and what the increment of the increase should be.
I think he's very likely high from getting too much insulin, not from too little. When the dry food carbs went away, he got down to 70. I'd like to suggest that you reduce his dose at his next shot. I think i would go to 1.5u and hold it for at least 6 cycles to let things settle and see what that dose will do for him.
There are 2 other important pieces to this puzzle - as folks have suggested already, it helps tremendously when you vary the times of your tests. If I remember correctly, you're running home from work to get that mid-day test - is that right? Just any variety on the times of the testing helps us see better what is going on.
Also, once you've increased a dose, you want to hold it for a minimum of 6 cycles (shots) before considering a dose increase. If you post here before increasing a dose, there are several of us who watch out for people wanting help deciding if it's time to increase the dose. we can teach you what to look for in making that decision so it's done safely.
Does this make sense to you? I know it is counter-intuitive. Do you have any questions? What do you think about doing the reduction?