Hi
If you are planning on a complete curve, then you just test every two hours from the time of his AM pre-shot test.
So yes, test him for his AMPS, feed him and shoot. I'm not sure what the vet's logic is for waiting a half an hour.
Do you test, feed and shoot all within a few minutes at breakfast time?
The +2, +4, +6 routine are all hours after the first test of the day, and your +12 should be twelve hours later, when you test him for his PMPS.
Keep notes as to when he eats, and how much along the way, so his numbers will make more sense to you. An hour or so after eating, you would expect to see a small increase in BG when the glucose from the food enters his system, and a corresponding drop in BG when the insulin starts to work against that increase.
You don't want him to eat in the two hour period leading up to his shots, because that would give you a false high reading. He can eat at any other time during the day though.
Have I confused you enough? ;-)
Carl
Carl