Hi and welcome to you and Buddy.
Great you have set up the spreadsheet and are hometesting.
Can you tell us what type of food you are feeding?
Are you testing, then feeding, then waiting 30 minutes before giving the dose of insulin?
Are you giving a couple of snacks during ALL the cycles as well as the 2 main meals.
With caninsulin I would give the snacks at +2 and +4
I would recommend you get at least one test in every PM cycle as cats often drop lower at night. A before bed test is a good habit to get into and it that test is lower than the preshot BG you would be advised to test again a bit later to see how low the BG is going and if Buddy is safe. At the moment we don’t know what is happening for 1/2 of the time.
With those black and red BGs I would say it is a combination of bouncing and lack of duration.
Caninsulin is not a good insulin for cats. It is a dog insulin. It does not last the 12 hours which is necessary, as cats have a faster metabolism than dogs.
I would suggest you look at swapping to either Lantus (which is my preference) or Prozinc. These are much more gentle, longer lasting insulins and cats do well on them.
I am going to tag
@Suzanne & Darcy about the dose as she is a Caninsulin user.
BEGINNERS GUIDE TO CANINSULIN