Here's my take on it:
- 4 u might be too high a dose but we'd need data from BG tests over time to know for sure
- those highs in the AM might be from a rebound phenomenon we call bouncing that can happen for a variety of reasons, one being a dose that's too high
- he won't stay at one BG for 12 hours - that's not how this insulin works. He'll slowly drop from the AM high to the lowest point (the nadir) about half way through the 12 hours between doses and will then rise up to a level similar to the AM in the evening. Some cats will stay at or near a good BG for 12 hours if the owner is using a depot insulin like Lantus or Levemir, the cat is moderate in his response to insulin, he's well-regulated and is being dosed optimally.
A case can be made for keeping a dose at least a week if it seems to be a sensible starting dose (often 1 u twice a day), seems to be giving decent numbers or you're waiting for BG to settle. Many cats are very erratic at the start.
This is a high-ish dose for a relatively newly diagnosed cat. You also say in your signature that you're on your third insulin since diagnosis on June 6. That's
a lot of change in a very short period of time. We generally recommend sticking to one insulin for at least 6 months to get to know its action well. There is the odd exception where it's obvious a kitty can't tolerate an insulin. Being volatile and not giving good numbers quickly doesn't fit in that category. This type of up and down is typical and it can take many, many months or longer to work out good dosing and to start seeing decent regulation. Was it your vet that recommended those insulin changes or were you worried that Queed didn't become regulated right away?
No, this wouldn't be safe. The shortest interval between dose changes we recommend with ProZinc is after three 12 hour cycles. That's only done when you (and we, if you ask for help) can look at a spreadsheet of a lot of data to see what the current dose is doing.
This process can't be rushed. There's no quick route to regulation unfortunately, which is why you'll hear "it's a marathon, not a sprint" so often on FDMB.
The best thing you can do right now to allow us to give you the best advice possible is to set up the spreadsheet we use here and enter all BG numbers you have so far into it. There arte members who can set it up for you if you need help.
@Chris & China is one.
http://www.felinediabetes.com/FDMB/threads/fdmb-spreadsheet-instructions.130337/