Hi Looby,
No, there isn't a single document that covers all of the above, but do have a read through of the Caninsulin/Vetsulin user guide which has quite a lot of helpful info.
Vetsulin/Caninsulin user guide
As a
general rule, for those new to dealing with diabetes (and new to hometesting) we recommend that NO insulin is given if the blood glucose at the time of the shot is below 11 (200).
That's just until the caregiver has got comfortable with hometesting, and has gathered some data to show how the insulin is working in the cat's system.
If the number is too low to shoot, you can either skip the shot completely, or wait
without feeding for a little while to see if the blood glucose
rises on it's own to a shootable level.
Later on, when you've learned a bit about how the insulin is working in your cat's body, you might also decide to give the shot but to give a reduced or 'token' amount.
Ultimately whether you give the shot or not is your decision. You're the one holding the syringe.
Regarding preshot tests: I crumble a few freeze dried treats for Bertie and test him while he's munching on those. These seem to have no impact on his blood glucose. This might work for you, too..?
Caninsulin
usually does 'most of it's stuff' in the first 5 hours after the insulin shot, after which the blood glucose will rise.
A cat may see the lowest number of the cycle at around 4 - 5 hours after the insulin shot. But some cats will have the lowest number a bit
earlier than this, and some may have the lowest number a bit
later.
It can be helpful to test the blood glucose during the first hours of the cycle to see how low the blood glucose is dropping, and also how fast the blood glucose is dropping. If it is dropping too low or too fast then giving food can help to slow down the drop and/or to reduce the amount of the drop.
The Caninsulin user guide suggests that, in most cases, the aim should be to not let the blood glucose drop below 5.6 (100) at the 'peak' of the cycle.
So, if you see a '5.6' earlier in the cycle, and there is still some time to go until the peak (lowest number), you may need to give food (or glucose if there's a very steep drop) to raise the blood glucose level, or to stop it from dropping any further.
That '5.6' is a perfectly safe number, but
aiming to not go below that gives some 'buffer of safety'.
Hoping this helps.
Eliz