New Member, Cat not Responding to insulin

[CaseyJones]

I adopted my 7 year old diabetic neutered male cat Gilbert from the APL about a month ago. The shelter gave us a vial of Lantus with the instructions to give 2 units (u-100 syringes being used) every 12 hours for life.

After a couple weeks I acquired an Alphatrak glucometer and found his BG was consistently over 500 no matter what time of day I took a reading.

Upon discovering this I increased his Lantus to 3 units every 12 hours about a week ago. Today I took his BG 4 times starting 2 hours after giving insulin/feeding and then every 2 houra and got the following results: 530, 480, 470 (probably the nadir), then 500. It seems like the increase in Lantus had a very minimal impact in reducing his BG if it's had any impact at all.

Gilbert weighs 11-12lbs. I feed him about120kcal of canned patte wet food (typically friskies or fancy feast) around the time of insulin injections. I also give him 1/2 of a very small cat treat after poking him for BG checks to make him not hate the experience as much.

I am concerned because 3 units of lantus seems like an already quite high dose, yet I have NEVER recorded a BG that was less than 400 for him (I have checked his BG repeatedly in a wide variety of different times in relation to when he gets his insulin). The vast majority of his BG checks are 500-550. Occasionally I get a couple in the 400s.

The shelter he was in was steadily giving him more and more Vetsulin (he was up to receinving 8 units twice a day with BG in the 500s before getting switched to lantus). He was in the shelter for months and the records seem to indicate that he never got regulated.

I am not really sure what to do next because he doesn't seem to respond to insulin. Should I try continually increasing his lantus? Does he just need more time? Is he likely to be insulin resistant?

My other concern is that if his BG is just doomed to remain 400s-500s no matter what I do, how much time will Gilbert have before he starts to get very sick and die?

At this time he has a very active energy level and doesn't come as sick or lethargic at all. His coat is a little dandruffy and oily. His body condition score seems healthy. He does seem quite hungry all the time. His thirst and urination doesn't strike me as really all that excessive (it was worse at the time adoption).

Any support or suggestions would be greatly appreciated. Thanks

 

[Sienne and Gabby (GA)]

Welcome to FDMB.

There are a couple of factors to consider. What is the expiration date on your Lantus? Also, do you know how the insulin was handled? Lantus tends to be a bit more fragile than other insulin. For example, if the shelter was shaking or rolling the vial or pen, you don't need to do that! Can you see any crystals in the insulin? If so, the insulin is damaged.

If Gilbert was getting 8u of Vetsulin, it may take a while to get him to a compatible dose of Lantus. I would also be curious as to how often they were testing. Vetsulin and Lantus are very different types of insulin.

What are you feeding your kitty and do you know what they were feeding him at the shelter? If your cat was on a dry food diet, there's a good chance that it was high in carbohydrates. Carbs are the last thing a diabetic needs. If this is the case, then a large dose of insulin was likely needed to offset the effect of the high carb food. And please don't be fooled by thinking that if you're feeding your cat a prescription diabetic diet that it's low in carbs. Unfortunately, there are very few diabetic foods that are low in carbs. We can help you with the food issue.

There are plenty of cats that are in high numbers and are essentially asymptomatic. Most of us have no idea how long our cats were diabetic before we realized that they had diabetes. In other words, please don't panic! However, as a preventative measure, I would pick up some Ketostix so you can test for urinary ketones. With a cat in higher number ranges, you want to know if there are ketones present as they can be a health risk.

It's great that you're home testing. That is a huge hurdle to cross. If you're planning on sticking around, we'd ask that you take a look at this post on helping us to help you. It will provide you with information on how to set up a spreadsheet so we can follow along with Gilbert's progress and you can keep track of your test data. There's also information on setting up a signature so we don't plague you with the same questions repeatedly. There is also other helpful information in the post I linked.

Please let us know if you have any other questions. The people here are very generous with their knowledge and time.

 

[CaseyJones]

The expiration date on the vial isn't until 2025. I think the vial was first punctured about 25 days ago today. I keep it in the refrigerator. After I draw it up I do sometimes softly roll the syringe between my finger and thumb to get it closer to room temperature. The contents of the vial look perectly clear to me. I can only assume the clinical staff at the shelter knew what they were doing when they gave it as well.

I feed him about 120kcal of canned patte wet food twice a day (usually Friskies or Fancy Feast). I break a very small cat treat in half for him after checking his bg.

My issue is not so much that I was ever unaware of his being diabetic, it's that his insulin seems to have little to no impact on his BG even when handled and administered properly with a high protein low carb diet given only once every 12 hours. Increasing it also had little to no impact. I'm not really aware aware of what changes I can make at this point?

 

[Chrispooky12]

The expiration date on the vial isn't until 2025. I think the vial was first punctured about 25 days ago today. I keep it in the refrigerator. After I draw it up I do sometimes softly roll the syringe between my finger and thumb to get it closer to room temperature. The contents of the vial look perectly clear to me. I can only assume the clinical staff at the shelter knew what they were doing when they gave it as well.

I feed him about 120kcal of canned patte wet food twice a day (usually Friskies or Fancy Feast). I break a very small cat treat in half for him after checking his bg.

My issue is not so much that I was ever unaware of his being diabetic, it's that his insulin seems to have little to no impact on his BG even when handled and administered properly with a high protein low carb diet given only once every 12 hours. Increasing it also had little to no impact. I'm not really aware aware of what changes I can make at this point?

What kind of treat are you giving him? It could be the problem I give boiled chicken breasts cut up as a treat, it's 0 carbs.

 

[Sienne and Gabby (GA)]

Thanks for filling in with more info. It certainly sounds like you're doing the right things.

Generally, when switching a cat from another insulin to Lantus, you keep the same dose or reduce it by around 30%. You were instructed to basically start over. I would not raise the dose too quickly. Lantus is a very different insulin than Vetsulin and after a dose change, you need to hold the dose for up to a week for the dose to stabilize. How long you hold the dose depends on the dosing method you're using. This is a link to information on Lantus dosing.

The other possibility is that Gilbert is a high dose cat. What that means is there may be an underlying condition that causes him to need a higher dose of insulin. You can have him tested for acromegaly and insulin auto-antibodies. Blood is sent to the vet lab at Michigan State University where the tests are done. I'm tagging @Wendy&Neko who can provide more information.

 

[Wendy&Neko]

Some cats just need more insulin than others. Reasons differ, sometimes it's a secondary endocrine condition causing the need for higher doses. My girl had two such conditions, one called acromegaly (hypersomatotropism) and IAA or insulin auto antibodies. Acromegaly is caused by a benign pituitary tumour that excretes excess growth hormone, which in turn eventually causes the diabetes. About 1 in 4 diabetic cats has this condition. Not all need higher doses of insulin, but needing higher doses of insulin means it's a definite possibility IAA is the body's reaction to injected insulin, think like an allergic reaction.

Neko was on 5 units of Caninsulin (Vetsulin just a US rebrand), then switched to Lantus. Unfortunately at too low a dose per vet recommendation. She eventually got up to 8.75 units of Lantus before she got to a dose where she started needing less insulin. Plus around that time, I had her acromegaly treated.

The being hungry all the time can be a sign of acromegaly, though an unregulated cat will also be hungry a lot. I couldn't keep food on the kitchen counter anymore. You can also spread out the meals a bit or feed mini meals so it's not so long in between feedings, if that helps.

If you are interested, you can enter the blood sugar readings you are getting into our spreadsheet. Details in the link Sienne listed in post #2. By taking a look at the spreadsheet data, it can sometimes provide a clue as to what is happening.