Do I test it prior to giving him his insulin and after he has eaten and then test it again after he has been given his shot to see where it stands? I just know that when I tested it yesterday 6 hours after giving him his insulin it was 96 which to me is normal and where he should be. I just don't know what it was after giving him his 2nd shot last night. Maybe I should have tested it again after I gave him his shot but then again I would have to wait 6 hours since my vet said to test it 6 hours after giving him his shot... My question is, why do I have to wait 6 hours to test? I want him to be on best insulin made for cats but I also can't afford to pay over $100 a month
So generally HumulinN will give you a short curve, dropping after the preshot to a low somewhere in the 3-7 hour range . The lowest point depends on how the cat's body responds to the insulin and unfortunately, most often, that varies with the cat. So we encourage you to find your cat's pattern, so you can keep him safe.
If, for example, your cat drops fast, in the first 3 hours, and then starts immediately back up, you can watch for that and help with the low number by feeding or feed earlier to soften that drop. It's a matter of trying to manage the cat's reaction to the insulin in the best way possible and keep him in safe numbers (below 50 and we worry about hypo)
If your cat is one of the lucky ones and does better with N, maybe that low will be later in the 5-7 range and then the insulin will last longer. There is no way to know if that 96 was his lowest point or not, without the numbers around it. If that was his lowest point at +6, that would be great. Then you want to know how long the insulin lasts. Does he jump up 8-10 hours after the shot to a high preshot? Or does it last longer?
Once you have the testing data, then you can figure out how best to help your cat. Sometimes feeding at different times helps, sometimes with N people try dosing every 8 hours (only after getting lots of data) because the insulin only lasts 8 hours. There are ways to work with N but you need data.
And we do always test before each shot. You need to know how high he is - did he bounce back up from a low point or is the insulin not lasting 12 hours? And if he would ever surprise you with a low preshot (under 200) you'd want to lower your planned dose.
A few People here do use N and some have had success. We like the longer lasting, milder insulins because they tend to have softer longer curves - easier on the cat and his parent. We can help you work with N, if you want us to, but only if we have numbers to work with. We wouldn't want to give you ideas about dosing with only limited data.
I hope that makes some sense. Here is a primer on N. It is a little outdated as it was written when it was one of the only insulins available. Few people use it now because there are better alternatives.
http://www.felinediabetes.com/FDMB/viewtopic.php?f=19&t=303