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)