10/14 Hermano (Diagnosed last month) - High (300) AMPS with low (120) PMPS - Somogyi?

[UncertainP]

Hi everyone!
First post, I'm so impressed at this community - the wealth of knowledge, the kindness, and compassion I see all around here. I will figure out how to setup my signature and all that soon. I wanted to ask for some advice in the meantime on his response to dose:


My 11.5 y/o neutered male Hermano was diagnosed Aug-28-2025:
Blood panel: 561 mg/dL, normal SDMA (8.7 ug/dL)
Urine @vet: 4+ glucose, negative for ketones
No weight loss, we took him to Vet as we noticed increase PU/PD.

Prior to starting SLGS w/ Lantus on Sept-14-2025, Hermano was converted to a LC diet of 85-90% wet and was hovering around 320 mg/dL.
Started with 1.5U BID Lantus (6AM/6PM) and we have worked our way up to about 2.75-3U BID.

Typical response:
High AMPS -> Dose -> BG falls very quickly over 2 hours -> stable and slightly decreasing till PMPS which makes me feel weird about PM dose.

I find it odd that his AMPS is high but his PMPS is low. I was trying to rule out Somogyi or Dawn effect or just bouncy transient behavior while we power through. Hoping for some others' experience.

Here is some data from the past week:

And here is a libre CGM from last night, the 50 mg/dL values are artificially low in my opinion. Human blood meter (Contour) showed ~67 and feline meter (AT3) was ~105 (I've noticed at low BG, the meters diverge compared to at >120 when they tend to be within 15-25%:

Thanks again, I will do my best to integrate with the SS that you all use and fix my signature. I have to run to work - all the best!

 

[Lauren & Esse]

Welcome! We usually have first-time posters write into the Feline Health - (Welcome & Main Forum) board--so you may find it helpful to repost there. I'm happy to hear you're planning to set up your signature and spreadsheet, as that info will be very important to help us help you. You've included a lot of the info for the signature in this post, which is awesome. What food do you feed Hermano? Does he have any other conditions/medications besides FD/Lantus?

A few things--

• We don't really use the term Somogyi here, as it is not an evidence-backed term for blood glucose patterns in cats. More info here: Chronic Somogyi Rebound: Myths and Facts. What you're likely experiencing is what we call "bouncing," where kitty's body is not used to experiencing lower numbers after being high for so long. In response, the liver and pancreas may respond by releasing a stored form of glucose along with counterregulatory hormones. This causes numbers to spike back upward. Some kitties bounce only for a little bit, some bounce all the way to remission. For example -- if you look at my spreadsheet and compare the BG patterns from, say, July to how they are now, we used to experience a lot of what you are seeing currently. The only time a high AM pre-shot/low PM pre-shot pattern is 'problematic' is when it prevents you from shooting the PM number. In those cases, our dosing experts (of which I am not one) may recommend re-starting at a lower dose so you're able to shoot consistently.
• I'm happy to hear that you're able to manually check kitty's glucose manually with the Contour/AT in addition to the Libre. You're correct that the Libre is less accurate at low numbers. More on using the Libre here: Getting Started With Continuous Glucose Monitors (CGMs) for Diabetic Cats. When you're setting up your FDMB spreadsheet, I recommend using LibreView to download an Excel sheet with all of your data. Look for the Download Glucose Data button in the upper right hand corner. That will make it easier to input old info. No need to go all the way back to August right now, just the last two weeks or so is fine.

Overall it sounds like you're doing an amazing job so far caring for Hermano! When you have more time to get settled in here, we'd love to see a picture!

 

[UncertainP]

Welcome! We usually have first-time posters write into the Feline Health - (Welcome & Main Forum) board--so you may find it helpful to repost there. I'm happy to hear you're planning to set up your signature and spreadsheet, as that info will be very important to help us help you. You've included a lot of the info for the signature in this post, which is awesome. What food do you feed Hermano? Does he have any other conditions/medications besides FD/Lantus?

A few things--

• We don't really use the term Somogyi here, as it is not an evidence-backed term for blood glucose patterns in cats. More info here: Chronic Somogyi Rebound: Myths and Facts. What you're likely experiencing is what we call "bouncing," where kitty's body is not used to experiencing lower numbers after being high for so long. In response, the liver and pancreas may respond by releasing a stored form of glucose along with counterregulatory hormones. This causes numbers to spike back upward. Some kitties bounce only for a little bit, some bounce all the way to remission. For example -- if you look at my spreadsheet and compare the BG patterns from, say, July to how they are now, we used to experience a lot of what you are seeing currently. The only time a high AM pre-shot/low PM pre-shot pattern is 'problematic' is when it prevents you from shooting the PM number. In those cases, our dosing experts (of which I am not one) may recommend re-starting at a lower dose so you're able to shoot consistently.
• I'm happy to hear that you're able to manually check kitty's glucose manually with the Contour/AT in addition to the Libre. You're correct that the Libre is less accurate at low numbers. More on using the Libre here: Getting Started With Continuous Glucose Monitors (CGMs) for Diabetic Cats. When you're setting up your FDMB spreadsheet, I recommend using LibreView to download an Excel sheet with all of your data. Look for the Download Glucose Data button in the upper right hand corner. That will make it easier to input old info. No need to go all the way back to August right now, just the last two weeks or so is fine.

View attachment 74467​

Overall it sounds like you're doing an amazing job so far caring for Hermano! When you have more time to get settled in here, we'd love to see a picture!

Hi Lauren,
Thanks so much for the welcome and the links! Will educate myself on the bouncing and CGM when my workday relaxes a bit.

No other health issues thankfully.
Like you, I feed him FF classic paté (per my research on catfooddb) and supplement with a tiny amount of dry Purina Pro Plan Weight Control (LC for dry; 40-50 cals) here and there if I feel he needs it.

 

[Lauren & Esse]

Wow, what a beautiful guy! I love kitties with nose freckles.

But yeah, feel free to take your time -- if you're anything like me, you'll do all the reading and then have a million more questions, haha. Seems like you're the research type as well.

 

[UncertainP]

Hi Lauren,
Thanks so much for the welcome and the links! Will educate myself on the bouncing and CGM when my workday relaxes a bit.

No other health issues thankfully.
Like you, I feed him FF classic paté (per my research on catfooddb) and supplement with a tiny amount of dry Purina Pro Plan Weight Control (LC for dry; 40-50 cals) here and there if I feel he needs it.

View attachment 74468

Excellent resources RE: Bouncing & CGM. Thanks so much <3