? How can you tell if your kitty is developing a resistance to insulin? (lantus)

Hi all,

I want to preface by saying don't look at my sheet because I haven't updated it since I think May. (bad me, new years resolution is to keep that thing updated)

So, Harry was on 0.5u (Lantus) for a good while, and he was doing well. Hanging out near 100, feeling great, being playful. After a few months, the insulin expired and his numbers were climbing, so we ordered some more. Until it got here, we wanted to keep giving him the old stuff, but it didn't seem to be impacting him at all so we stopped using it because there was no point. He maintained 320ish for about two weeks until the new stuff got here, and he's been on the new stuff for a little over a month.

We started him at 0.5u since that's what he was on before. However, he was been staying in the 300s. +0, +2, +6, +8, +10, he was always around 320. So we've been gradually increasing the dose and are now up to 1.5u and have been for a little while now, but his numbers aren't doing anything. I think the lowest I've seen him since we got it is 280. That says to me that we're not giving him enough, but... 0.5u was working just fine before, so why would he suddenly need so much more?

I'm wondering what the best course of action would be... I worry he might be developing a resistance to it, but I don't know how I'd know. As far as I'm aware, it's the same exact stuff, it just isn't expired. So what do I do? Should I keep slowly increasing him? Why would he need such a drastic increase? My knowledge on how Lantus works is a little rusty, but I know that he should be doing better by now.

Anything helps, even if it's just telling me to keep slowly increasing it. Just frustrating to see him not feeling great.

 

It would be very helpful if you update your SS with recent BG, including recent curves.
Without more information I can't give any suggestions.
A cat's insulin needs can change with time, even a short period of time. Until one gets to about 5 units BID I would not consider looking for insulin resistance.
My MurrFee had acromegaly, a high-dose condition. At the end he was on 50 units BID. I got him tested for a high-dose condition when I could not get good BG at 8 units BID.

 

When was his last vet check-up? Sometimes, if there's something wrong (dental troubles are common), BG and (apparent) insulin needs can increase.