New member, newly diagnosed kitty, overwhelmed and exhausted

[Amy and Owl]

I don't know where to start this. My cat, Owl (10yrs old domestic shorthair) was diagnosed with diabetes on 12/31/26 after I had noticed him guzzling water, peeing a lot, and being generally not himself. He had, one week prior, begun treatment for hyperthyroidism (methimazole) when I noticed something seemed off and brought him in for more testing. The methimazole was discontinued temporarily while we worked to get his diabetes under control. We began injections of 1unit of Lantus 12/31/26 at 6:30pm.

On 1/2/26 we got a Freestyle Libre 3 installed on him and I was able to see his BG numbers for myself. For a few days things seemed to be progressing well enough, but on 1/8/26 his BG dropped quite low at midday, just before I would normally feed him lunch. I fed him, monitored, and it went back up. That night, after administering his shot, his BG dropped quickly and ended up bouncing between 50-70 for hours, all night long. The vet had told me if his BG went below 70 she wanted me to feed him and keep an eye on him and use Karo syrup if necessary, so that is what I did. All night long. The Freestyle app alarms went off constantly saying he was too low, and despite feeding him two Churus, a handful of Temptations, and about .3ml of Karo, his blood sugar hovered around 60 until 3:30am when it finally started to climb. He vomited around 3:30am, but I am uncertain if that was BG related or if he was just given way too much food, or if the Karo made him sick. The pamphlet I was given with his Libre instructed me that if his BG went this low I was to skip his next Lantus dose and contact the vet, so I did. I called as soon as they opened that morning to tell them what had happened. My vet called me back at 9:30am (she can see his BG remotely thanks to the app) and said that I did the right things, confirmed that I should skip his morning dose of Lantus. She called me again later that afternoon as Owl's BG had risen over 400 again and said he should have 1unit that night. This was last night.

I gave him 1unit last night 1/9/26 and his BG hit the 50s again sometime after midnight. It came back up again on its own shortly thereafter. Unfortunately Owl refused to be contained in my bedroom last night, so he was out of signal range for the app, and I was not alerted. This morning, due to the lows the last few days, I decided to decrease his insulin dose to .5units, which I just have to eyeball as my syringe doesn't have half unit measures. I fed him breakfast at 6:30am and gave him a half dose, but his BG has been climbing all day and hovering around 400, as if he didn't get any insulin at all. His vet called this morning and I told her I had given him a half unit and she said that was the right call. But seeing his numbers go high again is disconcerting and I feel like I am fighting a losing battle with his BG swinging wildly to both extremes.

I haven't slept more than an hour at a time in two nights, I'm exhausted, I'm worried, and I hope someone here can steer me in the right direction.

 

[CORKY]

@Staci & Ivy
@Wendy&Neko

 

[Staci & Ivy]

Hi Amy, welcome to you and Owl.
How is Owl doing today? Did you give insulin last night?
I was looking at your spreadsheet to try to see what’s going on.

It seems Owl is very responsive to insulin, which is a good thing. We will want to try to get you to a good and safe dose which you can give him twice a day, every 12 hours.

Have you read some of the stickies on this website to try to figure out what dosing method you would like to try to follow?
That will help to determine the advice that you get around here in terms of what blood glucose number you should safely give his shot.

Sticky - Dosing Methods: Start Low, Go Slow (SLGS) & Tight Regulation (TR)

As for the Libre, it’s great that you are using that to see what’s happening overall with his glucose. Are you able to blood test with an ear prick yet?
If it is possible to do that, it’s important to be able to determine especially when Owl goes lower on the Libre.

Many times, the Libre reads lower than a handheld glucose monitor will read.

For example, when my cat reads 50 or under on the Libre, when I blood test her with an ear prick and use a handheld glucometer, she is typically under 100 on a handheld meter.
When she hits 50 or over on the Libre, she is typically around 150 or higher on a handheld meter.
However, that can’t be said with every cat and every meter when blood tested. Some people here report very similar numbers between their Libre and their handheld meter, only about 10 or 20 points difference.

So, it seems that every cat is different and every meter may be different. So we can make general understandings of using the Libre, but we don’t have concrete comparisons from 1 meter to another.
If you aren’t able to blood test at all, then we have to go by what the Libre says.

I will link a document we have put together for using a Libre that will give you some more comprehensive information and understanding of how to use one safe safely with Owl.

I have been using a Libre for three years with my cat, so I’m pretty familiar with how they operate. If you have any questions, please feel free to let me know.
Getting Started With Continuous Glucose Monitors (CGMs) for Diabetic Cats

I’m hoping we can get you some advice regarding a safe dose to use for Owl.

It seems the dose may be too high if it’s dropping him that low and then he’s bouncing up high from those low drops.

When you feed him to bring his glucose up, just a little Karo goes a long way. It can make them vomit if it upsets their stomach if the get too much.
Just a teaspoon or so is what you’d want to use if needed.
And don’t overfeed, just a teaspoon or 2 at a time.
You want to keep them hungry if you need them to eat.
Do you have some medium or high carb foods on hand to use if glucose drops too low?
Please make a post every day to let us know how it’s going and with any questions you have so we can support you with what’s going on
@Suzanne & Darcy @Sienne and Gabby (GA)

 

[Sienne and Gabby (GA)]

Welcome to FDMB!

Just for a bit of reassurance... Numbers of 50 and above on a human meter are safe. That said, you don't have a much of a margin for error and you do want to be certain that Owl is in safe numbers. When testing with a Libre, as Staci noted, we often see that the Libre reads lower than a human meter once numbers are below 100 (on the Libre).

Since you are carefully monitoring when numbers are in the lower range, you might try giving Owl some low carb food first and see if that levels things off. Additionally, some cats are sensitive to the gluten in gravy based cat food. If that's the case, Karo or honey or anything similar is fine to use. You do want to not be overly zealous in giving your cat syrup though. This post on handling low numbers may also be helpful.

We use two approaches with Lantus dosing -- Tight Regulation (TR) and Start Low Go Slow (SLGS). You might want to review that information. Basically, with SLGS, you would have reduced Owl's dose.

As far as seeing higher numbers, there are two reasons I believe this is happening. First, skipping a dose can definitely cause numbers to rise. The other explanation is what we refer to as a "bounce." If a cat's numbers drop low, drop fast, or drop into a range that cat isn't used to spending time in, the liver and pancreas can overreact and release a stored form of glucose along with counterregulatory hormones that cause numbers to spike. It can take a few days for numbers to destabilize. Bounces are hugely annoying for the caregiver but they are not dangerous for your cat. It just takes a while for a diabetic kitty's system to get back to being used to spending time in normal numbers.

And please remember to take care of yourself. You can't be there for Owl if you're dead on your feet. It does get easier, though. You'll have a clearer sense of what is "normal" for your cat and what you need to do. In the beginning, we're all pretty much a wreck.

 

[Amy and Owl]

First, thank you both so much for taking the time to reply. I've been reading everything I can get my hands on, including all of the helpful info on this site, since Owl's diagnosis. I'll admit that it is an overwhelming amount of info to digest at once, especially sleep deprived, and I've found conflicting info across the web that has made me second guess what I'm doing. That said, I did manage to sleep last night and things don't feel quite so dire. For his part, Owl is doing fine. He is eating well and acting like his normal self. I'm no longer seeing the symptoms that prompted me to take him to the vet for diagnosis (excessive thirst, peeing a ton, generally being "off.") He is, as usual, supremely unconcerned with any chaos he may have caused

Hi Amy, welcome to you and Owl.
How is Owl doing today? Did you give insulin last night?
I was looking at your spreadsheet to try to see what’s going on.

I did give him insulin last night, per the vet's instructions. 0.5units at 6:30pm, and again this morning at the same hour. I did start to see his numbers go down last night, and while they are still too high, he did not exhibit that intense drop into the 50s like he had previously, which is why I did finally get some sleep. I will update his spreadsheet here in a minute. Am I correct that the severe drops in blood glucose he was exhibiting one 1unit dosage are indicative of it being too high a dose? Going from "HI" on the meter to 50 in a few hours is wild.

It seems Owl is very responsive to insulin, which is a good thing. We will want to try to get you to a good and safe dose which you can give him twice a day, every 12 hours.

Have you read some of the stickies on this website to try to figure out what dosing method you would like to try to follow?
That will help to determine the advice that you get around here in terms of what blood glucose number you should safely give his shot.

Sticky - Dosing Methods: Start Low, Go Slow (SLGS) & Tight Regulation (TR)

I am not entirely sure which method to pick, or what my vet may be wanting to do. Right now she wants me to hold him at .5units for a few days and see how he does. After the last few days, I think I am favoring the SLGS method. My biggest concern is him going too low while I am at work, as I have no way to monitor him remotely and if he did drop too low, neither my husband nor I could get home fast enough. It's really my biggest fear. I've modified my work schedule to be home with him for now, but I have to go back sometime.

As for the Libre, it’s great that you are using that to see what’s happening overall with his glucose. Are you able to blood test with an ear prick yet?
If it is possible to do that, it’s important to be able to determine especially when Owl goes lower on the Libre.

I am not sure if we can do ear pricks. Both of Owl's ears are unfortunately folded over with a lot of scar tissue (not sure what happened, he came that way.) The vet has told me recently that he was not a candidate for a topical med that rubs on the ears (mirtazapine, I think?) because of this. I don't know if I would be able to get blood from the scar tissue I will ask his vet. I don't think she intends for the Libre to be a long term thing, so I will need another way of testing.

Many times, the Libre reads lower than a handheld glucose monitor will read.

For example, when my cat reads 50 or under on the Libre, when I blood test her with an ear prick and use a handheld glucometer, she is typically under 100 on a handheld meter.
When she hits 50 or over on the Libre, she is typically around 150 or higher on a handheld meter.
However, that can’t be said with every cat and every meter when blood tested. Some people here report very similar numbers between their Libre and their handheld meter, only about 10 or 20 points difference.

So, it seems that every cat is different and every meter may be different. So we can make general understandings of using the Libre, but we don’t have concrete comparisons from 1 meter to another.
If you aren’t able to blood test at all, then we have to go by what the Libre says.

I will link a document we have put together for using a Libre that will give you some more comprehensive information and understanding of how to use one safe safely with Owl.

I have been using a Libre for three years with my cat, so I’m pretty familiar with how they operate. If you have any questions, please feel free to let me know.
Getting Started With Continuous Glucose Monitors (CGMs) for Diabetic Cats

I have also read that the Libre is less accurate in the double digits, but in the absence of any other way to test him that night I didn't want to risk him going lower and becoming hypo. I'm worried I overreacted and made things worse for him.

I’m hoping we can get you some advice regarding a safe dose to use for Owl.

It seems the dose may be too high if it’s dropping him that low and then he’s bouncing up high from those low drops.

When you feed him to bring his glucose up, just a little Karo goes a long way. It can make them vomit if it upsets their stomach if the get too much.
Just a teaspoon or so is what you’d want to use if needed.
And don’t overfeed, just a teaspoon or 2 at a time.
You want to keep them hungry if you need them to eat.
Do you have some medium or high carb foods on hand to use if glucose drops too low?

I do have high carb food, his original prescription food we swapped from when he was diagnosed. We switched because he was not eating it very well anymore, but I can always try some if he goes low again.

As far as seeing higher numbers, there are two reasons I believe this is happening. First, skipping a dose can definitely cause numbers to rise. The other explanation is what we refer to as a "bounce." If a cat's numbers drop low, drop fast, or drop into a range that cat isn't used to spending time in, the liver and pancreas can overreact and release a stored form of glucose along with counterregulatory hormones that cause numbers to spike. It can take a few days for numbers to destabilize. Bounces are hugely annoying for the caregiver but they are not dangerous for your cat. It just takes a while for a diabetic kitty's system to get back to being used to spending time in normal numbers.

And please remember to take care of yourself. You can't be there for Owl if you're dead on your feet. It does get easier, though. You'll have a clearer sense of what is "normal" for your cat and what you need to do. In the beginning, we're all pretty much a wreck.

The vet also felt that his high numbers currently are due to bouncing, and we should give him a few days on his new lower dose to see how things shake out. Since his half unit dose this morning, he has gone from 350 to 230ish, then back up a little bit and is currently 292, after eating lunch. Am I correct that it will take a few days for this new lower dose to take full effect? I've read about the depot action of Lantus, that it takes some time to build up and show its true effectiveness, does that also apply to lowering a dose?

Again, thank you both.

 

[Sienne and Gabby (GA)]

I would not immediately conclude that because there's a sharp drop in numbers that the dose is too high. One truism for most cats is they hate to be predictable. There are going to be days when it's completely smooth sailing and then there's every other day. There may be days when numbers sit in a higher range -- sometimes for explainable reasons (e.g., you're having your roof repaired and there's a lot of strange people around and a lot of noise) vs times when there's a completely inexplicable reason (e.g., some cats seem to have higher numbers during a full moon). The same can be true for lower numbers. Anything that has an effect on stress levels can have an effect on blood glucose numbers. All we suggest is that you follow the guidelines for a dosing method so you are consistent with what you are doing.

It sounds like your vet may be familiar with the TR approach. Unless your vet has been on FDMB, she's unlikely to be familiar with SLGS. The method may be similar but the name we use came from here. If you refer to SLGS with your vet, it's unlikely she'll know what you're referring to and definitely conclude you've been on the internet and getting information from "crazy cat ladies (and men)".

With Lantus, you need to let a dose stabilize. When starting out, it takes about a week for the dose to stabilize. Thereafter, the minimum amount of time that's needed is 3 days/6 cycles. However, the 3 days that you hold a dose is specific to TR. With SLGS, you hold the dose for a week. The exception is if a dose reduction is indicated and the point for reducing varies with the dosing method. Also, we adjust doses in 0.25u increments. You will want to get syringes that are in 0.5u amounts.

I worked full time when treating Gabby's diabetes. It's feasible. A timed feeder will help a lot. You'll also get more comfortable with knowing if your cat's numbers are dropping and can leave higher carb food. One thing I did was shoot early (5:00 shot time) so I could see where Gabby's numbers were going before I left the house. I was able to run home in the evenings and shoot and then go back to work if I scheduled a 5:30 meeting.

One thought about manual testing. If she will permit, you can test on a paw pad.