Lantus...numbers still high | Feline Diabetes Management Board

Lantus...numbers still high

Hello! Our kitty Peanut, who is 13, was diagnosed with diabetes in March. We started with Catsulin and that did nothing. We switched to Lantus and our best glucose number at the 6 hour mark was 396...while she was still on higher carb food and 4 units twice daily. Our vet keeps putting her dose up and now she is at 6 units twice daily and her 6 hour numbers are in the 425 to 430 range. Could this be too high of a dose? She had a complete check up with bloodwork and urinalysis in March and everything else was ok. Thanks!
 
Hello and welcome to you and Peanut. There's a few questions I need to ask first before I can answer. Some of the answers to those questions can go in your signature, as they are questions others will have too. Details on that information, and more, in this post: New Here? How to Help Us Help You

Of most interest at the moment is what food Peanut is eating regularly. The second question is whether you are home testing his blood sugars, or whether those numbers you posted are from the vet? Also, if testing, what type of meter you are using.

I presume you meant Peanut was started on Caninsulin/Vetsulin? Good thing you switched to Lantus.

Once I can see more information about food and blood sugars, I'll have a better idea to answer the questions. I can see three scenarios being possible. Once is that is too high a dose. The second is that the food is not appropriate for a diabetic and keeping Peanut in higher numbersd. And final possiblity is that Peanut is a cat who needs a higher dose. My girl had a couple secondary conditions that meant she needed to get up to a 8.75 units dose of Lantus.
 
Hello! I filled out my signature and the spreadsheet. I updated the spreadsheet just now! Peanut is eating mostly wet food and I make sure I read the label so that there aren't any sneaky carbs in the food. She also free feeds Dr Elsey's dry food. We have been doing the testing at home with the Alpha Trak3. Yes, she was on Vetsulin for a month before we took her back to the vet and said we wanted to change. So, from the end of March to the end of April she was on Vetsulin...waste of time. :(
She went to the vet for a complete checkup in March and everything was good for a 13-year-old cat. We have had her back to the vet multiple times since and the only other thing they were kind of concerned about but couldn't really tell us for sure (?) was her heart might be enlarged. We had her there 3 different times and got three different answers/concerns. It was really quite confusing and frustrating. It has been a hectic couple of months.
Any help is greatly appreciated. I have learned more reading the message board than from my vet.
Thanks, Karen and Peanut
 
It's hard to tell from the data you've gathered so far whether Peanut is overdose or under dose. We recommend getting tests every day before each shot, then at least one more sometime after each shot. Lantus nadirs (low points) are typically in the 4-7 hours range after the shot, but that can vary by cat. Knowing typical nadirs for your cat will help you be more strategic about when to test. My girl was in the 7-9 hour range on Lantus, except when she wasn't. 🤣. We determine how to change the dose based on how low it takes the cat. Many cats go lower at night, so we also recommend a "before bed" test, or a test just before you turn out the lights for the night, hopefully that's at least 2-3 hours after the PM shot.

Relatively newly diagnosed cats (and some not so new) often do what we call bouncing, which can lead to temporary higher than normal numbers. If you test at the wrong times, that's all you'll see and you won't see how low the dose is taking the cat in between bounces. Here is the explanation of a bounce:
Bouncing is simply a natural reaction to what the cat's system perceives as a BG value that is "too low". "Too low" is relative. If a cat is used to BGs in the 200's, 300's, or higher for a long time, then even a BG that drops to 150 can trigger a "bounce". Bouncing can also be triggered if the blood glucose drops too low and/or too fast.The pancreas, then the liver, release glucogon, glycogen and counter-regulatory hormones. The end result is a dumping of "sugar" into the bloodstream to save the cat from going hypoglycemic from a perceived low. The action is often referred to as "liver panic" or "panicky liver". *Usually*, a bounce will clear kitty's system within 3 days (6 cycles).

What brand of wet food is Peanut mostly eating? Are you using U-100 syringes to give the dose? What type of kitty is Peanut? I'd love to see a picture, you can put one in your avatar.

Lastly, is the vet following up with the possible enlarged heart. Recommending an echocradiogram perhaps? Heart disease can be a form of insulin resistance. Neko had HCM (hypertrophic cardio myopathy) or enlarged heart for a couple years that didn't require any treatment. But she also had some Maine Coon in her, so bigger cat.
 
Thank you so much for the information! I will attempt to test her more...she is pretty good about things so it shouldn't be too bad. I will update the spreadsheet as we go along!

As far as the wet food, we have been trying a lot of them. She is super picky. Right now it is mostly the Fancy Feast petites pate with Tiki Cat tuna broth mixed. I tried the Fancy Feast classics, 3 different seafood flavors, and all were a nope from her! LOL. I also add tuna (in water) to the mix just to give it a bit more flavor.

We (my boyfriend and I) are using the U-100 syringes. And we change them every dose...we do not reuse them.

I will add Peanut's picture! She is a shorthair striped cat with white mixed in.

Our vet did NOT tell us that an enlarged heart could cause her to be insulin resistant! There is a feline cardiologist that comes to our area once a month and our vet said if we wanted to, to make an appointment. She really didn't push it. And our vet does not do echocardiograms....it would have to be a specialist. :(

THANK YOU again for all of this information!
Karen and Peanut
 
I love Peanut's while collar! So cute.

With a previous kitty, I went got an echocardiogram from a specialist who travelled to vet offices. That's a solution that can work. I agree it's best done by a specialist. I've heard of someone who got all worried about something that they didn't need to when the echo was done by a regular vet.

Mixing up test times will help us decide if you are missing some low numbers that cause bounces, making it look like the dose is too low, when in fact it is too high. Not all Lantus cats have their lowest numbers at +6. My girl it was more like 7-9 hours after the shot. Getting tests before you shoot will tell you if it's safe to shoot. Every once in a while a cat will surprise you with a lower number at shot time. For people for whom testing is hard to do, the Freestyle Libre is one possible solution. It works for cats who are fractious or feral, though cats typically learn quickly that test time = treat time. Neko used to run to me when she saw me picking up the test kit.
 
It looks like you've been getting up to speed and answering all of Wendy's questions. And thanks for getting your signature and spreadsheet set up. That helps us a great deal!

I'm going to suggest a bit of homework to hopefully help you get more background about Lantus and how it works. At the top of the Lantus board, there are several sticky notes. The notes provide general information about the insulin, dosing methods (as Wendy mentioned, if dry food is in the picture, you need to follow the Start Low Go Slow method), and much, much more.
 
Hello! Yes, I will read the sticky notes...they are super informative. I did a test today at the 6 hour mark again just to see, and her number is super high. Because she has the enlarged heart and that makes her insulin resistant, does this mean that her numbers will never drop? Or are her numbers still high because we just haven't found her correct dose yet? I am super nervous about the number being high...it was 471 when I tested. I saw that Wendy said her kitty was better tested at 7-9 hours after the shot.....I am going test again at the 9 hour mark just to get another number. Tomorrow I will start with doing the pre shot testing and go from there.
Thank you again!
kk and peanut
 
Because she has the enlarged heart and that makes her insulin resistant, does this mean that her numbers will never drop?
No, the enlarged heart should make no difference, only if it got much worse. When Neko was in a congestive heart failure crisis her numbers temporarily rose, but came back down when she was treated. The issue is that you may not have the correct dose for Peanut.

As I mentioned above, the 6 hour mark may or may not tell you anything. I'd really work on trying to get those tests in the AM and PM before you give insulin, to make sure it's safe to do so. The value of the 6 hour test (we call it +6) compared to the preshot test can provide a lot more information than one test by itself. It can tell you if her numbers are moving at all, and in which direction. That CHF crisis I mentioned above, I gave insulin at 86, and two hours later she was at 434 and we rushed her to the ER. That's an unusual example as her body was very stressed at the time. She was down to 83 in the morning at the ER after she was treated and on supplemental oxygen. Numbers tell a story, but only in relation to other tests in the same day and few days around it. We can't tell much from single tests spaced apart by several days.

The typical Lantus cycle has higher numbers at the beginning and end of the cycle (time between shots), with lower numbers somewhere in the middle. But cats don't always like to be "typical". And that bouncing phenomenon I mentioned above can mean a cat goes low at some point, followed by up to 3 days of higher numbers.
 
Thank you! I will start tomorrow doing a pre-shot test and then one sometime after. I did do one yesterday at the 9 hour mark and it was 492....I was getting worried. I was super hopeful she was at least staying in the lower to mid 400 range but nope. She has been a bit more perky lately which I have been super happy about.

I will start tomorrow and record everything in the spreadsheet....you guys are at least giving us a bit of hope.

thanks!
kk and peanut
 
Great to hear you're starting up tomorrow. With regard to testing, it's important to get both AM and PM cycle tests. It's critical to always test at shot time -- it's the only way you'll know if it's safe to give insulin. You also want to get at least one additional test during both the AM and PM cycles. Ideally, you want to be able to know when your cat's lowest point in the cycle is (nadir) since this tells you if you need to reduce the dose. Lantus dosing is based on the lowest number in the cycle and not on the pre-shot value. Many cats experience lower numbers at night that's one of the reasons to get a test in. We often suggest that you test around your bedtime so you can go to sleep not worrying about whether Peanut is in low numbers. In addition, if you don't get any tests at night, you're missing half of your data and you won't know if you need to change the dose.
 
We did our pre-shot test today...of course, her number was super high. Going to test again at the 5 hour mark. We have never had any kind of low reading for her. The 396 reading was a glimmer of hope that was short lived.

I check her water bowl (always at least half-way gone over night and I fill it before bed) and her litter box (always full and I clean it before bed) before giving her a shot in the AM. Her drinking and peeing are so ridiculously bad that we know her number is super high right before the shot. Would it ever be the case that her number would be low even though the drinking and peeing are so much??? Neither of those have gotten any better, and honestly, some days they are worse.

Sorry if this message sounds sad....just frustrated!
thanks!
kk and peanut
 
Karen --

The way your spreadsheet reads, it looks like you're not giving a shot at PMPS. If you're giving insulin then, please write in the dose in the "U" column. Also, please test before you give a shot. Again, there's no test data in the PMPS column.
 
I updated the PMPS column. We just started the pre-shot testing today. I will update again once we do her shot tonight.
I did test today at the 6-hour mark and of course it is still super high. I updated the spreadsheet.

thanks!
kk and peanut
 
For any insulin, you need to get a minimum of 4 tests per day. You need to test at AMPS and PMPS. In addition, you need at least one test during both the AM and PM cycles. The tests that are after the pre-shot may tell you if numbers are dropping and if you need to test more. For many cats that are newly starting insulin, their numbers may bounce. For example, last night, your PMPS was 518. Even if Peanut's numbers dropped to 350, he may not be used to being in that range and as a result, his liver and pancreas released a form of stored glucose along with counterregulatory hormones. This causes numbers to spike. Getting more test data tells you how the insulin is working. In addition, you'll have a way to know if numbers are dropping into a low range and you need to intervene. Without PM tests, you're missing half of your data.

Also, please stick with the SLGS dosing guidelines. Lantus is a depot type of insulin. Back-to-back increases can cause issues with numbers and potentially drop Peanut into a dangerously low range. When you change a dose, you need to give Lantus a chance to stabilize.
 
Hello......I have been doing the 4 tests a day and the numbers are super scary. Especially the one I just did. Her glucose is 638. I did a control test on the Alpha Trak3 and it is calibrated correctly. I was really hoping it wasn't. We did go to the pharmacy today and get a new vile of insulin and we just used it and gave her the usual 6 units. We have been giving her a steady 6 units since 7-6-2025. We are thinking of calling our vet tomorrow to see if we should increase it once we hit the 7-day mark.
 
Karen:

I've asked a few of the experienced members to keep an eye on Peanut. In the meantime, I want to make a few suggestions.
  • First, raise Peanut's dose to 6.5u.
  • Is it feasible to stop feeding Peanut the Dr. Elsey's? It is low carb and is fine from that perspective. However, I think Peanut would be better served if you were using Tight Regulation and you can't use that dosing method if Peanut is eating dry food. TR will allow you to raise the dose every 3 days.
  • Once a kitty is at a dose of 6.0u or more we recommend that you talk to your vet about testing for a high dose condition. Specifically, this means testing for either acromegaly or IAA. Acro results from a benign pituitary tumor that secretes growth hormone and throws blood glucose numbers out of whack. @Wendy&Neko has a great deal of experience with kitties with this diagnosis. IAA is insulin auto-antibodies. The way I think of this is like an allergy to the insulin you're giving Peanut and it causes insulin resistance. IAA is self-limiting. At some point, there's a break in the high numbers -- we just can't predict when that will happen. The only place in the US that they test for these conditions is at the Michigan State University Veterinary Diagnostic Lab. This post from the Acromegaly, etc. forum has background information on these conditions along with a link to the information for getting the lab work. The cost for the labs is not prohibitive but your vet needs to send/FedEx a blood sample and those costs vary.
  • If you're not already doing so, please test for ketones. This is a preventative measure. With high numbers, there is a greater risk for ketones developing and ketones are something no one wants to see. There are urine test strips (Ketostix) that you can find at any pharmacy. You just have to stalk Peanut to the litter box. We have info on how to get a urine sample if you need help with "technique." If Peanut is shy about you're being around when he's in the litter box, there are blood ketone meters. The meters involve pricking your cat's ear.
Please let us know if you have questions.
 
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I agree with Sienne's suggestion to raise her dose to 6.5 units. The best way to get over those high numbers is to get to a dose that moves her blood sugar down as soon as is safely possible to do so. Every cat gets to a dose than moves them eventually. The sooner the better.

The suggestion of testing for secondary conditions is also a good one. There are treatments for acromegaly, should that be something she has. Research (published 2015) shows that about one in four diabetic cats has acromemaly. Not all acrocats need higher doses, some do. Neko had her acro tumour treated with stereotactic radiation therapy and her dose got down to less than one unit over time. That was 13 years ago, there are newer types of treatment now, including a medicine given at home. I had a three day drive for treatment, each way.
 
Thank you for all of the information. We are going to consult with our vet. Seeing the numbers on the spreadsheet is a true eye opener and it's obvious she is getting worse. We are going to make some decisions over the weekend. I doubt our vet will do anything else for us because she is basically just giving us the insulin prescriptions and has said in the past that there really isn't anything else they can do on their end. There is a possibility of finding an internal medicine vet (we believe there is one in our area) but with her age and her enlarged heart, we are hesitant to torture her with anything. We have seen a big difference in her in the last week...and not a good one.
Thanks again,
kk and Peanut
 
Something for you to consider this weekend. If she does have a secondary endocrine condition, a hallmark sign of it is that the insulin resistance grows and ebbs. You may be in the phase where it's growing. I've seen cats older than Peanut, in worse shape, still get to a good insulin dose and do much better. The key is being willing to be a bit more aggressive with the insulin dose increases and home testing. A slightly enlarged heart by itself means nothing. Neko had a slightly enlarged heart with no other impacts on her life for three years, before things got worse. Neko had almost 5 years as a diabetic, almost all of that with good quality of life.

There is a good chance that your vet just hasn't read about IAA and/or acromegaly. Vets "over a certain age" were taught at school - this is acromegaly, you'll never see it. My vet was one of that age. After she learned with us, she discovered another acro in her practice. Neko's acupuncture vet was the same. She thought she'd never seen it either. After doing some reading and spending time with me and Neko, she realized that the neighbourhood stray she'd adopted in the past, had likely been acro. How I managed to get Neko treated was with the good folks on the FDMB.

If your vet is willing to work with you, learn with you and get the tests done, we can help with the rest. By the way, it took a lot of arm twisting for me to get the tests done. I had to plead for her to humour me. Thankfully the research showing how common these conditions are has come out since, and there are papers you can send your vet, which make it easier now. We can also show you papers showing the success of treatment, cabergoline being the medicine mentioned above. There are other more expensive options, but cabergoline is easier, cheaper, and still has good results. One of our kitties named Tiger has gone from 8 units to 2 units dose in the three weeks he's been on cabergoline. Not all kitties respond that quickly, and a few have done even better (off of insulin now), but all see improvement, getting to good doses.
 
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I agree with with everything Wendy and Sienne have said.

I’ve had 4 diabetic cats — one “garden variety” old/overweight/lifetime of high-carb foods, one steroid-induced, one acro cat, and one former feral who was in diabetic ketoacidisis when I realized she was sick.

Where I’m going with all of that is that most of the time the prognosis isn’t as bad as it feels like it is, despite the current angst and stress of high numbers, confusion over what’s happening and how to proceed, large learning curve, etc.

In your case, you’re not even certain Peanut has a heart issue. And even if she does, it might be an incidental finding for now. I wouldn’t let that muddy the waters or influence your decision to treat the diabetes.

Secondly, please don’t get too hung up on high BG numbers. It’s not at all uncommon to see that in the early days/months after diagnosis. Peanut is MUCH more than her BG numbers and, hard as it is, try not to let the high numbers get into your head. This is a marathon, not a sprint.

Along this vein, one thing that’s good to consider is the Whole Cat Report. How are Peanut’s “5 P’s” — peeing, pooping, playing, purring, and preening?

Finally, please remember that feline diabetes is not a death sentence. You’ve already made giant strides by getting Peanut on an appropriate insulin, finding this group, educating yourself, collecting BG data, and being responsive to suggestions and requests. You’re being an excellent advocate for her. Kudos.

The folks on this site live “in the trenches” of feline diabetes, acromegaly, and many other concurrent illnesses that we’ve dealt with along the way. If you feel hopeless, please post and someone will probably have been where you’re at and share their experiences. Mostly I want to encourage you not to give up. The hardest days are often the early days.
 
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Hello! I finally had a chance to fill in the spreadsheet. We did give her a bit of a break. A few of the tests at least dropped in the 400s.

Thank you for the encouraging words. We did have a diabetic cat before, but our old vet just kept him for the day, continually tested him, found the correct dose and we never had a problem. Only had to give insulin once a day and he was good to go. We were kind of shocked that this is so complicated! (Side note...our old vet was Dr. Kathio....he was awesome, google him for a good read!). Our newer vet is awesome too....and young. We can discuss the acromegaly with her and see what she says. We are going to call and discuss where we are at with Peanut anyway.

We did increase her dose to 6.5 on 7-12-2025. We will leave it there for a week and see if we keep getting the numbers down in the 400s.

Peanut is a bit slow but she did go up on her favorite window perch today. She hasn't done that for about a week. We will look into getting a ketones test kit.

Thank you again!
kk and Peanut
 
Hi Karen and Peanut, just wanted to send you both lots of good wishes. Excellent advice has been shared here and hoping you can work with your vets to get Peanut to feeling better.

Please don’t give up hope. There’s so much good advice and help here 🍃🍃🍃🍃🍃🍃🍃
❤️‍🩹😻💕
 
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