OK, good to know. Let me explain why I asked the question.
This is what
could have happened. No way to know for sure, and I try to never reach a conclusion with anything "diabetes" based on just one cycle.
If Tommy has been used to a set amount of food with his shot in the morning, then that food will "boost" his BG by putting glucose into his bloodstream. Then you add insulin to the mix, and they basically try to fight each other. But in general, during the first couple of hours after eating, the food gets digested and gets converted into glucose and whatever else it gets converted to.
With PZI, about two to three hours after a shot, the insulin reaches "onset", and it starts to combat the increase in blood glucose, and sometime around 5-7 hours after the shot, it "peaks" (nadir would be the lowest BG of the cycle), then gradually loses potency and wears off as you get close to the next shot 12 hours later.
Alright, so this morning, he ate less. So maybe his BG didn't climb as high as it usually does after breakfast. And then the insulin kicks in, and works against a lower BG than usual. So it appears to "onset" a little sooner, and it pushes the number down so that by +4, it's lower than you would expect it to be.
You did the exact right thing by feeding him at that point. And if that point had happened at +6 like you were hoping for, everything would have been "right on schedule".
If this is what happened, I think there's two ways to address it. Either shoot just a tad less insulin when you see a 265, and go with the split breakfast like you were planning.
Or, give him his normal breakfast and normal dose, and then "add" a couple tablespoons of food around +4 or +5 - sometime just before nadir is supposed to happen. That can stop the number from dropping lower than you want it to go, but you'd be doing it proactively instead of reacting to the low number after you see it on the meter. A lot of that would be determined by his current weight, and if he's under or over weight. If you can add a 1/4 can or so to his total food for the day, you could go with option 2 (assuming he's not overweight currently). That might get you what you're after.
Is having a more constant BG better than the higher, low, then higher? I would like Tommy to be more consistent in the blues.
I think that's a good goal to have. It isn't easy to achieve, just due to the way the insulin works. You don't want the dose so small that it is doing little to nothing, but if you can manage to keep the numbers in the blues and greens, that would be awesome. Eventually, you'd be able to shoot relatively small doses and hopefully see the numbers overall continue to come down. At first, most people see a lot of swings, and bounces, but as the cat improves overall, the cycles tend to become flatter, and the doses keep getting smaller.
Again, I can't say for sure that the above description of what I think
might have happened
did happen. But does it makes sense the way I explained it?
). Tommy has had good cycles with ProZinc and I haven't seen much evidence on past cycles of it not lasting long enough. So I am definitely voting for a bounce. Not that it makes any difference, really. Our suggestion moving forward will very likely be the same.....