cat keeps building restitance to insuilin

he was put on pzi it went down to mid 200 and he got sick with fatty liver diease and we about lost him.changed to humlin N and the lowest it has gotten is mid 400 so they put him back to pzi 2 times a day. i live in a small town so the vet is at a lost and dont know what else to do

 

Welcome!

The most likely problem isn't insulin resistance, it's frequency of testing. I am guessing from what you don't say, that your blood sugar tests are taking place at the vet's, and at some undetermined time after the last shot.

A typical cat after an injection of insulin has their blood sugar go down for a few hours, then come back up again over a few more hours. 12 hours later sometimes it's as if the insulin wasn't there at all.

Different insulins have different typical lengths of action, and each cat has a different reaction too. So although PZI typically lasts about 8-10 hours in cats, some make it last a full 12.

Humulin N typically lasts more like 5-7 hours in cats, and makes a rather sharp dip in blood sugar, often dipping to a dangerously low peak around 3-4 hours, before rising rapidly again. If the dip is too deep, it can activate the cat's liver's own defenses, dumping glucose into the bloodstream and rapidly raising blood sugar even higher than it was to start with, which might explain your test over 400.

One more important thing is that stress (such as that of being at the vet's) causes cortisol and epinephrine to be released into the blood, which both quickly act to raise blood sugar. In some cats this effect is minimal, in others it is dramatic.

So your vet's conclusions about insulin resistance tell me he or she is not experienced with cats with diabetes. There are many things you can do to help out.

1. Get an inexpensive human glucometer from the drugstore and start testing your cat's blood sugar at home, frequently. (You don't need to do it more than 2 times a day in the long run, but for now you need more data to decide what to do.) It's easy after a few days, see this:

http://www.youtube.com/watch?v=_zE12-4fVn8

2. Switch back to PZI for now (Humulin N is too fast acting and short-term for most cats), and start with a lowish dose (0.5 units) and gradually increase by no more than a half-unit, every other day.

3. Use a spreadsheet such as (can someone please link to the google docs template?) to record your blood sugar tests. We can help you figure out how long your insulin is lasting and how effective it is, and suggest when to change dose.

4. Others will chime in on diet recommendations. These will save you lots of money and make regulating blood sugar possible, and are very important.

There you go, breathe easier, you have found a lot of experienced folks!

Best,
Steve and Jock

 

Here is the link to the directions for starting your own spreadsheet. http://www.felinediabetes.com/FDMB/viewtopic.php?f=9&t=157 You can see an example by looking at mine in the signature line. It is very helpful for you and everyone else that you ask advice of. It gives everyone a quick snapshot so they are all on the same page with you. I totally agree with the testing at home advice - if I had kept going the way that I was (checking BG level once a week 1hr after shot) Oliver may have died by now. He was getting WAAY too much insulin and since we (vet or I) hadn't done a curve on him we had no idea that he wasn't hitting his nadir (lowest point) until 3 hours after getting a shot. When I did a curve - which you can also see in my signature line as a download - he dipped all the way to 30!

Check back often and ask all the questions you can think of - there is a good chance someone here has already found an answer by trial and error. Good luck!

Thanks to Tugger's mom for giving me the link to the SS to start with.