New Member - Libre Confusion

[Anna & Leela]

Hi all! I’ll have to change my name to include my cat’s name as well once I can, but we have a newly diagnosed (2/14/26) diabetic cat named Leela. She is 12.5 years old and has also been diagnosed with IBD and triaditis. Her diabetes was induced by prednisolone (she was switched to budesonide after diagnosis). She started at 1.0U of glargine every 12 hours 6 days ago and due to lack of response the vet increased to 1.5U after just a day or so. She was pretty sick at the time (not eating, vomiting). She had a freestyle Libre sensor applied by the vet. The vet checked the sensor in the office a couple days after it was applied and found it to be about 18mg/dL low compared to their handheld. She has been much better for a few days and mostly back to herself.

All seemed to be going well until this morning when she was generally 115-140mg/dL on the Libre.

I double checked it using a Reli-on handheld monitor. She was reading at 97mg/dL and the Libre around 118mg/dL at the same time.

Isn’t the Libre generally lower than a handheld monitor? I’m not sure what to make of this and am concerned about such low numbers. I did not give the AM shot.

 

[squeem3]

Yes, the Libre generally reads lower than a regular blood glucose meter. Some people like to double check with a handheld meter, especially if the Libre reads LO. There's more info on using a Libre here: https://felinediabetes.com/FDMB/thr...ucose-monitors-cgms-for-diabetic-cats.303722/

If your cat will let you use a handheld meter and tolerates her ear being poked and messed with, you don't need the Libre at all. The Relion is fine to use and way less expensive than a Libre which you need to replace every 2 weeks or sooner if it falls off or malfunctions.

@Staci & Ivy can give you more advice on the Libre.

All the Lantus info you need is here: Lantus / Levemir / Biosimilars

Newbies shouldn't give insulin if the cat tests under 150 mg/dl. This is to prevent a possible hypo. Insulin can pack a punch. 1.5 units is a bigger dose than what we recommend for most cats. 1 unit twice a day is the max for most cats and you need to stick with the dose for at least a week before increasing (or even decreasing) based on a curve.

Lots of cats here who were steroid induced like mine IBD is common with many diabetics. What do you feed your cat? Diet is important for both the diabetes and IBD, not sure about the triaditis your cat also has.

 

[Anna & Leela]

Yes, the Libre generally reads lower than a regular blood glucose meter. Some people like to double check with a handheld meter, especially if the Libre reads LO. There's more info on using a Libre here: https://felinediabetes.com/FDMB/thr...ucose-monitors-cgms-for-diabetic-cats.303722/

If your cat will let you use a handheld meter and tolerates her ear being poked and messed with, you don't need the Libre at all. The Relion is fine to use and way less expensive than a Libre which you need to replace every 2 weeks or sooner if it falls off or malfunctions.

@Staci & Ivy can give you more advice on the Libre.

All the Lantus info you need is here: Lantus / Levemir / Biosimilars

Newbies shouldn't give insulin if the cat tests under 150 mg/dl. This is to prevent a possible hypo. Insulin can pack a punch. 1.5 units is a bigger dose than what we recommend for most cats. 1 unit twice a day is the max for most cats and you need to stick with the dose for at least a week before increasing (or even decreasing) based on a curve.

Lots of cats here who were steroid induced like mine IBD is common with many diabetics. What do you feed your cat? Diet is important for both the diabetes and IBD, not sure about the triaditis your cat also has.

Thank you for your response! I’m confused because the Libre is actually reading higher than the Relion. I thought the Libre was generally lower. I’m confused on what to trust in this situation.

We did not give the insulin this morning due to the reading below 150mg/dL on both the Libre and Relion. Despite the discrepancy they were both low so we didn’t give the insulin.

The vet was the one who said to do 1.5U. I have been concerned that was too high. But when I gave 1.25U the other day, she never reached the blue numbers like she had been. Should I still discuss lowering it with the vet?

She is eating fancy feast chicken and liver pate at the moment and some of the Purina pro plan DM dry food (dry only when she refuses to eat wet). She can’t eat the FF long term because of IBD but it’s low carb. She’s only going to eat that until we can get RC select protein PR wet food (arrives today and we’ll start slowly transitioning). She had a bad reaction to hydrolyzed protein food so we’re trying the novel protein now. Hopefully that works for her. The food situation has been complicated.

 

[squeem3]

Lantus is a depot style insulin. It needs time to build up before it really works. Sticky - What is the Insulin Depot?

If you remove the DM dry food you may see a better response to the insulin.The DM stands for dietetic management, not diabetic management. It's too high in carbs for a diabetic. Some suggested lower carb dry foods to feed to a dry food addict are Young Again and Dr. Elsey's. Dry food can also bother the tummies of IBD cats.

Have you seen these two web sites on IBD in cats? There's good info there on diet and other ways to manage the condition.

IBDKitties – Helping Save Lives…One Paw at a Time
Feline IBD - Healing can happen!

Novel protein diets are best. Many novel protein canned foods are also low in carbs. Some commercially available brands to try are Rawz, Koha, and Rayne. The fewer fillers and other junk, the better. My cat can only eat rabbit. I feed a commercially available freeze dried raw food. I've always fed my cats a commercial raw food so it wasn't a huge change to switch. Making your own raw or even home cooked food are options. Lots of people have had to disagree with their vets about food and that's ok

More LIbre users who can help:

@Allie & Gen
@Lauren & Esse

 

[CORKY]

@Sienne and Gabby (GA)

 

[Anna & Leela]

Lantus is a depot style insulin. It needs time to build up before it really works. Sticky - What is the Insulin Depot?

If you remove the DM dry food you may see a better response to the insulin.The DM stands for dietetic management, not diabetic management. It's too high in carbs for a diabetic. Some suggested lower carb dry foods to feed to a dry food addict are Young Again and Dr. Elsey's. Dry food can also bother the tummies of IBD cats.

Have you seen these two web sites on IBD in cats? There's good info there on diet and other ways to manage the condition.

IBDKitties – Helping Save Lives…One Paw at a Time
Feline IBD - Healing can happen!

Novel protein diets are best. Many novel protein canned foods are also low in carbs. Some commercially available brands to try are Rawz, Koha, and Rayne. The fewer fillers and other junk, the better. My cat can only eat rabbit. I feed a commercially available freeze dried raw food. I've always fed my cats a commercial raw food so it wasn't a huge change to switch. Making your own raw or even home cooked food are options. Lots of people have had to disagree with their vets about food and that's ok

I spent quite a while yesterday reading about IBD, raw diets, freeze dried, etc. Up until now I just was doing what the vet wanted but I think I want to push for a referral to internal medicine at this point.

I’ve been pretty overwhelmed by everything. Just the shock of the diabetes diagnosis at first but then within a few days she had a bad IBD flare up. Then pharmacy messed up the insulin and I spent several days just trying to find a pharmacy that had the right insulin. Meanwhile we had several trips to the ER vet. It’s only been about 48 hours that she’s had an appetite again. I’ve missed a ton of work. I would like to look into a raw food diet but need a minute to breathe.

Should we just put her back on 1U every 12 hours (provided she’s above 150mg/dL pre-shot)? The vet is out today. The insulin depot makes sense and I’m guessing we should never have been on 1.5U. She’s about 10.5lbs for reference.

 

[squeem3]

What insulin did the pharmacy wrongly give you? Lantus is the brand name. The insulin is glargine. As long as that is what you get, the brand name or manufacturer doesn't matter. I currently have a box of generic glargine.

It's ok to advocate for your cat and push for a referral or whatever else you need You're paying the vet and you need to make sure your cat is getting the care he needs and you want.

If canned food is easiest for now, then feed that until you can look more into other diets.

 

[CORKY]

Welcome to FDMB
We all get overwhelmed when we hear FD, I myself had no idea cats could get diabetes and was not aware of tge signs, but it did and it does gets easier, you have a good insulin Lantus is a 12-hour insulin easy on the cat, since is a depot insulin you should feed several small snack or meals during the day, a food schedule is also good, no grazing, when a diabetic cat eats the glucose levels raise, so you want a true reading before shot, you are using CGM, so if you get a two digit number please re test with the ReliOn the Libre tends to read the high numbers higher and the two digits much higher than reality, if you vet suggests a curve you can do this at home, cats get very stressed at the vet and tge glucose level will be much higher and this can cause an unnecessary dose increase, a curve is testing every 2 hours for 1 cycle(12 hours) and wearing the sensor no need for a vet visit. Squeem3 is right diabetic cats need to have a diet of wet can or raw food between 0-10% carbs, cats cannot digest carbs, tge transition from dry to low carb is a sLow process, not to upset the stomach also tge switch to low carbs tends to cause a dip in glucose levels, so is good tho test every 2-3 hours for at least tge first day of transitions, with the CGM just keep a close eye to the numbers, we are here for you, keep posting

 

[Anna & Leela]

Lantus is a depot style insulin. It needs time to build up before it really works. Sticky - What is the Insulin Depot?

If you remove the DM dry food you may see a better response to the insulin.The DM stands for dietetic management, not diabetic management. It's too high in carbs for a diabetic. Some suggested lower carb dry foods to feed to a dry food addict are Young Again and Dr. Elsey's. Dry food can also bother the tummies of IBD cats.

Have you seen these two web sites on IBD in cats? There's good info there on diet and other ways to manage the condition.

IBDKitties – Helping Save Lives…One Paw at a Time
Feline IBD - Healing can happen!

Novel protein diets are best. Many novel protein canned foods are also low in carbs. Some commercially available brands to try are Rawz, Koha, and Rayne. The fewer fillers and other junk, the better. My cat can only eat rabbit. I feed a commercially available freeze dried raw food. I've always fed my cats a commercial raw food so it wasn't a huge change to switch. Making your own raw or even home cooked food are options. Lots of people have had to disagree with their vets about food and that's ok

More LIbre users who can help:

@Allie & Gen
@Lauren & Esse

What insulin did the pharmacy wrongly give you? Lantus is the brand name. The insulin is glargine. As long as that is what you get, the brand name or manufacturer doesn't matter. I currently have a box of generic glargine.

It's ok to advocate for your cat and push for a referral or whatever else you need You're paying the vet and you need to make sure your cat is getting the care he needs and you want.

If canned food is easiest for now, then feed that until you can look more into other diets.

The original insulin was incredibly incorrect. The pharmacy admitted they substituted what they had on hand even though it was wrong. It was 300U/mL, like toujeo max solo Star or something (3x the concentration of lantus). It was not lantus. We have the correct one now. It is generic lantus (semglee).

 

[squeem3]

Yikes How does that even happen?? I hope you complained to the pharmacy manager about their mistake.

 

[Anna & Leela]

We did! The vet had the phone recording proving it was called in right and them admitting they filled it wrong. The refunded us and we went to another pharmacy to get it filled. I am so glad I trusted my gut wasn’t right, because I was brand new to this and thought maybe I just didn’t understand the numbers on the box!

 

[Staci & Ivy]

Thank you for your response! I’m confused because the Libre is actually reading higher than the Relion. I thought the Libre was generally lower. I’m confused on what to trust in this situation.

We did not give the insulin this morning due to the reading below 150mg/dL on both the Libre and Relion. Despite the discrepancy they were both low so we didn’t give the insulin.

The vet was the one who said to do 1.5U. I have been concerned that was too high. But when I gave 1.25U the other day, she never reached the blue numbers like she had been. Should I still discuss lowering it with the vet?

She is eating fancy feast chicken and liver pate at the moment and some of the Purina pro plan DM dry food (dry only when she refuses to eat wet). She can’t eat the FF long term because of IBD but it’s low carb. She’s only going to eat that until we can get RC select protein PR wet food (arrives today and we’ll start slowly transitioning). She had a bad reaction to hydrolyzed protein food so we’re trying the novel protein now. Hopefully that works for her. The food situation has been complicated.

Hi Anna, welcome to you and Leela.
You have been given great information above from several of our members.
I am a longtime Libre sensor user with my kitty and there are several of us on here.
If you choose to continue to use a Libre, we can help. The document which has been linked above is one we assembled and I think is very helpful.

You are correct, the Libre "usually" reads lower than a handheld meter. However, we have had some members report what you have seen, that the Libre was higher.
I don't know why, but it's good to be aware and if you can test with an ear poke, that's the most reliable test.

Some cats (like mine) won't allow constant ear pokes, but I can test her if necessary to double check a Libre "Lo", which is under 40 on the Libre.
With my cat, she's usually 60-100 when her Libre reads Lo. (not gospel for every cat however!)

I also strongly suggest checking out the Facebook group Freestyle Libres for Dogs and Cats, tons of users and great information there.

And applying the Libres at home is very easy and less stress for your cat and you. Just takes a little practice (and I have a very feisty girl).

Please let me know if you have any questions!

 

[Anna & Leela]

Thank you! I read through all the documents you all have linked previously. I’ve been reading everything I could find on this forum for days before I posted and joined Facebook groups for the Libre for pets, raw diets for IBD, etc. I have my hypo toolkit, multiple threads and info posts printed and put on my refrigerator, I even have my calipers set up for dosing and my spreadsheet going. I bought the lower carb FF pate to eat as that’s what was recommended here and she just needed her appetite back. I have a chart of all the foods she has tried, the carb calculations for each on a dry matter basis. As soon as I can breathe I will figure out the long term diet and see if we can do raw or at least commercial raw with a novel protein. I also bought skin tac so next time the Libre is applied I will have my vet use that instead of glue.

Leela’s BG is hanging at 150mg/dL on the Libre right now. Her PM shot is normally around 9pm. We will wait and see what her BG is then and double check with the Relion. I am frustrated we had to skip the AM shot and afraid my vet has led us astray on dosing Hopefully we can get on the right track.

I appreciate all the kind words and support! The cat is snoozing right now and I think she is tired of me asking her if she’s okay I am going to try to work some before I get fired!

 

[Staci & Ivy]

Thank you! I read through all the documents you all have linked previously. I’ve been reading everything I could find on this forum for days before I posted and joined Facebook groups for the Libre for pets, raw diets for IBD, etc. I have my hypo toolkit, multiple threads and info posts printed and put on my refrigerator, I even have my calipers set up for dosing and my spreadsheet going. I bought the lower carb FF pate to eat as that’s what was recommended here and she just needed her appetite back. I have a chart of all the foods she has tried, the carb calculations for each on a dry matter basis. As soon as I can breathe I will figure out the long term diet and see if we can do raw or at least commercial raw with a novel protein. I also bought skin tac so next time the Libre is applied I will have my vet use that instead of glue.

Leela’s BG is hanging at 150mg/dL on the Libre right now. Her PM shot is normally around 9pm. We will wait and see what her BG is then and double check with the Relion. I am frustrated we had to skip the AM shot and afraid my vet has led us astray on dosing Hopefully we can get on the right track.

I appreciate all the kind words and support! The cat is snoozing right now and I think she is tired of me asking her if she’s okay I am going to try to work some before I get fired!

We totally understand! You are doing great, try to breathe, and we are here to help. We know how you feel like everyone in your life does not. It's just not possible for them to get it.

As for the skin tac (great job) it's not a glue of any kind, it's really a moisture barrier and won't "help" the Libre to stick. But it has its job. And yes, the glue the vets use is very damaging to the sensor and their fragile skin (they all seem to want to use it, but I promise, it's not needed. I have NEVER used it and never had one just "fall off".
Now Ivy has pulled one or 2 off if I left it uncovered, (shame on me)