I feel for you, Megan. There isn't anything about this that's easy, and then to have the vet giving you grief and wanting to control everything would be overwhelming. All I can say is what i would do/did. The choice is always yours.
When I look at Oren's ss, it looks to me like a high dose kitty. He had only one green cycle until after you passed 5u. If I were a betting person, I'd bet there is iaa involved. Notice how when you increase the dose, he gets to better numbers once, and then the dose stops working almost immediately. That is a hallmark of iaa.
On 4/30, you increased from 5.25u to 5.75 - he had one green cycle and then never again on the 5.75u. He even got down to the 50's on it, but after that first cycle, the lowest he got was in the 100's.
On 5/6 you increased to 6.25u and again, he got to green soon after the increase. This time on the 2nd cycle of 6.25u, but now it's been 5 days since that barely green test and he hasn't gotten back under 100 again.
With acro, the dose can just keep going up but that initial response to the dose is more a "symptom" of iaa. With acro a dose might work for quite a while, but if the tumor ramps up production of its insulin-like growth factor then you have to go up in dose again.
I think your vet is thinking in terms of a "regular" diabetic cat. I'd ask her how much experience she has working with a cat with a high dose condition. Just tell her that the people on this board who have experience with high dose cats think that it's very possible that Oren has either acromegaly or insulin auto-antibodies or both. The latest research is that 25% or so of diabetic cats have an acro tumor. Ask her if she has ever seen a diabetic cat with pancreatitis that needed that much insulin. We're concerned that decreasing his dose may result in him being in high numbers unnecessarily. Even without decreasing his dose, he's already developed a tolerance for this dose and it's no longer working for him. I agree with Wendy, in fact, I'd be increasing his dose. The trouble with staying at a dose that isn't working is that the cat develops Glucose Toxicity and then it takes increasing even more to bring the blood sugar down. With high dose cats the worst possible thing is to stay at a dose that isn't working - you don't want to end up with a gigantic dose if you can avoid it and staying on top of the blood sugar is the only way to keep the dose size down.
The last thing I want to do is add to your burden, but where would you be if those of us with experience weren't frank about what we see? I hope you've gotten a good night's sleep and feel up to taking this on tomorrow morning. I remember only too well the frustration of having a cat that doesn't fit the protocol, that is difficult to get regulated, and not having a vet that I felt knew enough that I could trust them.
If I were you, I'd tell the vet that I'm willing to try what she suggests after I get negative test results back on acro and iaa. In the meantime, I'd want those tests both done. You'll have the results in a week and those results will be your basis for how to proceed. Surely she can wait for a week for you to do things her way.
Whatever you choose to do, you know we're on your side and will do our best to help you.
