16yo suffering multiple recent hypo & rebounds showing neuropathy

The short story: I need major advice on whether or not to dose my cat (Dinah) in next day or not. (The situation is out of the vet's league). Dinah has suffered multiple recent hypos and severe rebounds. The hyperglycemia that has resulted from the high rebounds has started to cause a lot of neuropathic events (shaking her front legs out in front of her) and glassy-eyed staring off into space, as well as some sweet smelling urine that she is spraying all over our entryway and not in her box in the basement. She is clearly extremely stressed. At this point, I also believe that we have been overdosing her on insulin for 3-4 weeks (after many years of good control). Details below...

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My 16-yo female cat (Dinah) has been diabetic for 6 years. She free feeds on Fancy Feast chicken feast classic pate for this whole 6 years, as she required much less insulin than on DM (multiple trials of that at different times). Remission upon switch to wet food in year 1 plus a honeymoon or two in early years. Was on 0.25 or 0.1 units Lantus every 12 hours through early fall. Kept catching her PM numbers low, suggesting too much insulin. The minuscule dose (0.1 units), plus all the accuracy issues associated therewith were hypothesized to be the root cause (ie, maybe sometimes she was getting 0.05, 0.10, 0.15. It was easier when she needed 0.25 or used to need 0.5 at times).

So we recently tried switching to PZI because it's U40. This, coupled with using the U100 syringes, would make dosing more accurate. Vet recommended starting at 0.5 units. (Why I let myself be talked into 5X higher on PZI than on Lantus I'll never know... Yes, I know that they're different formulations and proteins at the amino acid level at several positions.)

We had a FreeStyle Libre on her, which just finished its 14-day run of data (I attached the data containing plots. The "12-23 PZI & Lantus" tab shows all of her real-time data over the last 14 days, most recent of which described further below). Before installing the sensor, she had been on the PZI for 10 days. Through the first week on the sensor, it was clear that she was getting too much PZI. One hypo experienced. Besides bona fide hypo, a lot of fast falls (75-100 BG per hour) and sharp rebounds. (With the new insulin, I didn't know what to expect and didn't know that her body would perceive fast drops from high numbers to still high numbers as life threatening and rebound hard. I just thought I had to get her to good range.) Also observed several 3-cycle stretches where the same dose would shift the BG curve higher and be less effective. (Her poor little liver... She was clearly fighting the overdose. It took me several days of reading about Somogyi and rebound to put two and two together).

This was all over the holidays, so unable to reach my vet who knew her history. (Plus, frankly, I think I know more about this stuff and my cat). Switched her back to Lantus exactly 4 days ago. Her third dose of 0.1 units post switching back to Lantus caused a major drop and hypo. This was after long periods of flat high numbers (which I can only assume in retrospect correlates with insulin overdose, so I probably overlapped way too early). Her 2nd hypo was really bad. Her BG shot up 100s of points in 30 minutes the second that she dipped into the 40s (I also gave dry food soaked in simple syrup, but I think her body did the real job, as she threw that up). I spoke with emergency vet. And since she wasn't actually manifesting seizures/etc, was advised to avoid further stress and monitor BG with sensor at home.

Since the hypo (about 60 hours ago), I let her go 19 hours without any additional insulin. Needless to say, she rose to above 500 ("HI" on the FreeStyle Libre). After watching her be literally off the charts for 6 hours and show some leg twitching, I went for what I will call a 0.05 units dose (below the zero marking but where I could see a speck of liquid in the syringe). That resulted in a drop to an asymptote of about 375 over 20 hours, when a rise started to be observed again. But it was flat for that time and jagged. I dosed again at 0.05 units, and she exhibited a more classic looking U-shaped curve that nadired at +8 and returned to pre-dose around 14 hours. So I hit her with 0.05 units again this morning at 7:20 am (Eastern). The sensor's 14 days were up. So I have no more high-resolution data other than through +2 this morning where she is going down. And my wife and I had to go back to work today, so no BG numbers during the day. At 5:20 pm (+10 hours) she was above AMPS numbers (444). A few minutes ago (+14.5), she was flat relative to +10 at 453. She made a sweet smelling urine (again in our entryway and not the box) earlier this evening. If she did show a nice U-shaped curve today and not a rebound, I'll never know since I have no data. All I know is that if she did, the cycle time was less than 10 hours after it being 14 hours with the preceding dose.

I did speak with the vet today, who suggested not giving insulin at all for a couple days and monitoring BG the traditional way with ear pricks. She also referred me to an internal medicine specialist in my area. Earliest appointment I could get with internal medicine was next Monday.

So I am sitting here asking myself - what the heck do I do for the next week? Do I leave her off insulin in case she has gone into remission? If she has, how long will it take before her BG goes back down? Will it even do that?! That's my worry. The consistently high recent BG has clearly caused neuropathy in her front limbs, glassy-eyed staring, and spraying sweet urine in our entryway. Do I let that high BG persist? For how long? Anyone have experience with what to do in a situation with confirmed insulin overdose over 3-4 weeks (at least) punctuated by multiple recent hypos and rebounds? I am feeling helpless and blind without the sensor and with a vet who's not sure either and has binned her into the 'tricky' cat bucket. (My vet is wonderful BTW. Just out of her league at this point). I wish I could get the internal medicine appt tomorrow...

I/we appreciate any and all help. File attached with all the data and my little diary of notes.
- Drew (me) & Dinah (my fur baby)

 

I am not an expert but I sounds like she needs such a low dose it's hard to be accurate

 

Hello and welcome.

Have you tried doing blood sugar tests with a traditional human meter? Of do you just have the Libre (now expired) as a way to test her? I'm not seeing the 0.05 unit dose taking her lower than 150, but she could still be bouncing. Bounces can take six cycles to clear.

I have not used the Libre, and find it a bit tricky to read the graphs, compared to the spreadsheet we are used to using. When you say Dinah was "hypoing", did she have signs of hypo? Description of levels of hypo here.

 

Apologies. I should have described the data.

The Libre takes a reading every 15 minutes for 14 days. So you are literally seeing (in real time) 14 days worth of data every 15 minutes on the figure. The y-axis is the BG, where the grid lines are every 50 units. The horizontal red lines across the figure are at 270 and 80 to give some sense of the range the vet has me keep her in all these 6 years. The vertical lines are when I gave insulin. The text boxes around each individual curves nadir are telling the units dosed and the type of insulin used. The left-most (earliest) data (in a salmon color) is PZI at 0.3/0.4/0.45 units per dose until she has an extremely sharp rebound during the curve labeled "0.5 units PZI". I watched her in real-time start to go into the 50s and so I busted out some dry DM food to head off a major hypo, but you can still see an incredibly sharp rebound a few hours later. After that, she started peeing outside the litter box, so I started backing off on the PZI dose from 0.3 units to 0.25 units to 0.20 units. This is the blue data in the middle days of the figure (the walk down in lower doses of PZI) where several flatter curves at high numbers are witnessed, as well as still quite severe drops and rebounds on some doses. So then I switch back to Lantus at 0.1 units. This is the green data on that occurs latest on the plot (right-most). I start her with 3 doses of 0.1 units and witness a major hypo. You can see this with a red text box calling out the hypo. She was at 50 for about 15 minutes, and her body's rebound kicked in hard. She rose like 250 points in less than 30 minutes (from 50 to 300). Post-hypo, during that cycle, you see her BG falling again, as the insulin is still working to take her BG down. But then she gradually rises to above 500, as I was too scared to administer any insulin. And she hangs out above 500 (the sensor is only calibrated to 500... so she could have been 600 that whole time for example) for many hours (also noted by a red text box near the top of the figure). I say enough if enough and dose 0.05 units. She comes down, but is flat and jagged for about 20 hours in the high 300s. When that starts to rise, I give the 0.05 units again. She gives a normal U-shaped curve over 14 hours, where she is sub-300 for about 9 of those 14 hours. And the nadir is right around 7.5 hours. I give one last dose of 0.05 units at 7:20am this morning, and the sensor captures 2 hours of data (all the way at the extreme right of the figure now) before it goes inactive. We test using a normal ear prick tonight at 5:20pm after home from work.

 

When you say you witnessed a major hypo what do you mean? Do you mean a drop in numbers or do you mean signs such as staggering, twitching, falling over?

You mention you let her free feed on fancy feast pates. What food do you feed when she drops low? It sounds as if you feed dry food. That stays in the system longer than high carb canned food and can contribute to the high numbers. Canned high carb food is better to bring the numbers up without prolonging the bounce into high numbers.
Do you feed her some higher carb food if you see she is dropping lower? I mean before she has dropped low.

 

Here it is with the units and text boxes. New to forum so not sure why I can't make the image any bigger. Re-attached the Excel file here with a new tab called "Simpler Plot" (rightmost tab in the file) that shows this image in full size.

I know it's not the spreadsheet you folks seem to use. But think of it as like taking your cat's BG every 15 minutes and having all of those data points to construct an extremely high resolution curve. You are literally seeing 28 individual curves in that figure over 14 days. The PZI ones (salmon and blue) are sharp falls and rises. And every time I tried to increase the insulin (by 0.1 units) to force her into the 80-270 zone, she became more and more resistant to subsequent doses. And I save a hypo on one of those days (2nd to last salmon curve about 1/3 from left of figure) by watching the data show it about to happen and forgoing it with dry DM kibbles. But, again, she rebounded ultra-hard. That all tipped me off to start weening down the dose (blue curves). After continued sharp decreases and rebounds or weird high flat/jagged behavior, I went back to Lantus (green). I'm just not sure where to go next. Skipped insulin tonight despite mid-400s. Will check in AM.

 

If you are skipping insulin shots I think you need to be testing the urine for ketones.
It is a simple test. You just need to get a bottle of Ketostix from Walmart or a pharmacy then collect a urine sample from Dinah. Dip the test strip into the urine then check against the colours on the side of the bottle exactly 15 seconds later. Anything above a trace of ketones needs vet attention. Ketones can form when there is not enough insulin, not enough food and an inflammation or infection. Ketones can rapidly lead to keto acidosis (DKA) which is very serious. Daily testing while the numbers are high or you are skipping shots would be advisable.

I am finding the attachments really hard to read and make bigger without blurring them. Is there any chance you could transfer some of those numbers over to our SS.? Even 2 weeks worth would be very helpful.

 

Forgive the 3rd consecutive reply, as I realized that I didn't answer your question about the hypo. She was not staggering, twitching or falling over. She was in a very deep sleep. When I observed her BG falling rapidly on the sensor (marked by red text box at bottom of figure toward the very right), I scanned her. She read "LO" (ie, less than 40). I pulled out dry DM, dribbled some simple syrup on them, and she ate it. Thirty minutes later, I could see the data from the sensor showing that she went from 50 to 300 during those 30 minutes. She threw up all the kibbles. Emergency vet call in middle of night suggested to wait it out rather than stress her out further by bringing her to ER, as she hadn't been manifesting seizures. She did throw up, but it was brief and isolated during that ferocious rebound. The other event like this was slightly less severe and happened several days earlier on the PZI. I was able to get ahead of it with two feeding of DM dry separated by about 30 minutes when she was in the 60s and coming down. So she only dipped into the 50s. But then a few hours that super-fast rebound is observed (like 50 to 350 over 2 hours).

 

When you say she was in a deep sleep, do you mean she was unconscious or do you mean she was just sleeping?

I see you have the spreadsheet up. That is great!! If you could add some pertinent numbers that would help a lot.

I think things could improve with the bounces back into high numbers you are seeing, if you could buy some higher carb canned food. Normally you only need to give a teaspoon of it to help stop the drop or increase the numbers. Honey or karo is needed if the numbers drop really low into the low 40s or 30s or lower. But just a drop of honey should be enough, then you test again 20 mins later to see if the numbers are rising. If not you repeat the process.
I will send you a link and look for some higher carb food in the 11-16% ( medium carb) and 17-24% (high carb). Fancy feast gravy lovers are good.

I think you can take down the 911 now as we are helping you thanks

https://catinfo.org/docs/CatFoodProteinFatCarbPhosphorusChart.pdf

 

First off, going down to 50 is lowish, but for most cats is not a true hypo unless they are showing hypo symptoms. A symptomatic hypo is more serious. The normal range of a cat is typically from 50-80, we just don't want them going any lower when on insulin. I have tested my non diabetic cat in the 40's. But some cats show hypo symptoms at slightly higher numbers, which is why Bron and I were asking if she showed any physical hypo symptoms.

Cats bounce (we don't call it rebound) when they get into numbers they aren't used to, or drop quickly. It's a normal process until a cat spends enough time in normal blood sugar number range and gets used to it. It looks like Dinah spends quite a bit of time above 250 and hardly any time under 100. So she's not used to normal BG numbers.

You may wish to read this post and discussion on the Libre. One of the recommendations is to have a manual meter around, and do ear or paw test when you see low numbers on the Libre. We don't have a good sense yet how low numbers on the Libre compare to what we are used to on human meters, or even the AT meters.

Am I correct in assuming the 0.1 unit dose only took her down to 50? Looks like she'd be safe on the 0.05 unit dose, though I'd like to confirm by seeing data on the spreadsheet.

 

Well done getting those numbers posted on the SS!!!

on 3jan can you put in the pm cycle that she dropped under 40 at 4.75 please? Just stack the numbers in the +4 column and add 40 (or whatever it was) @4.75
Thx

 

Great job getting started on the spreadsheet. On the days that you start a new type of insulin (ie, PZI to Lantus), could you put a blank line before the day you start Lantus, and put something like "start Lantus" on that line. That'll just make it visibly easier to see when you switched.

ETA: I'm going to take off the 911, cause there is no immediate danger to Dinah.

 

Thank you for replies. Took down 911. Appreciate ketone monitoring suggestion. Our AccuChek meter (no idea if folks use that one on this forum or not) for humans corroborates the Libre when we sporadically used it and compare numbers. Granted, I did not bust out that meter when she showed the asymptomatic hypo to validate the "LO".

And yes - it was the 0.1 units Lantus on dose #3 upon reverting back to it that caused the recent hypo. I am calling it a hypo because I got a "LO" reading (ie, less than 40) and within minutes of that reading you see it shoot from 40 to 91 and then all the way up to 288 by 80 minutes later. I can't imagine a raise of 248 BG in 80 minutes is good. It was also accompanied by 2 rounds of vomiting and 3 or 4 minutes of water drinking after 2nd vomit.

Am I correct in that the one suggestion above was to use food with more carbs such that the insulin dose she requires is something higher to enable me to provide larger more accurate doses? That's an interesting suggestion, but one I've been afraid to try.

On the flip side, given that she requires so little insulin, any chance if I don't give her any over next couple of days, her high BG would go down on its own? Vet is suggesting to withhold even the miniscule 0.05 units right now and monitor BG. But I'm not understanding how long that sugar would take to clear her system if, in fact, she had lost her dependence on insulin. Not providing insulin after doing so daily for 6 years is unnerving. And besides peeing sweet-smelling pee in an atypical location, she is also showing front leg twitching. A month ago, we'd see a PMPS over 300 and think there was something wrong. Now she's been living above 300 for weeks and with periods of major swings. Ok... signing off for tonight. Need a few hours of rest. Thank you for all of the replies.

 

I think it would be worth while getting her urine testing for a UTI if she is peeing on inappropriate places.

I wasn’t suggesting you give higher carbs to give more insulin. I was suggesting you give her some higher carb food when she is dropping low during a cycle to stop her dropping into territory that may make her bounce.

 

Her numbers don't look like a cat that is ready for remission. I would expect a lot more green first.

As for food, I think the Chicken Feast you are giving now is around 3% carbs. You could try giving her something in the 8-9% carb range and see if that helps you safely giver her those tiny doses. Plus I agree with Bron about trying to slow the drops. Higher carb does not have to be high carb dry. Just somewhat higher carbs. Each cat differs in how carb sensitive they are so you have to take good notes and see how much carbs works to slow her down, not cause her to rocket up the other direction.

And yes, some people here use the Accucheck. It would be good to try it at the low points, should you see them again.

If you withheld insulin, you would have to wait for the bounce to clear, plus a couple days after her last high carb dry food.

 

Thank you again for all of the thoughtful replies. I have bought ketostrips this evening and will use at next opportunity. I also appreciate advice on what I might use if encountering a hypo in the future. I also appreciate the idea of maybe using a higher carb diet to combat the ultra-low insulin dose problem. And just to clarify - she does not get dry food. She has been on wet food (Fancy Feast classic chicken pate) for basically 6 years. I used dry DM kibbles a few nights ago when her BG went below 40. And several days earlier when it looked like it was destined to go below 40 before it ever go there.

While I appreciate all of these tidbits and discussions of what is and what isn't hypo, etc, I am still desperate for advice about the present situation (dose or not to dose?) given the totality of what I've been seeing with her these past few weeks. I feel like I missed the signs that she was trying to go off insulin and instead created a huge storm.

It is currently 36 hours since her last dose and she is just sitting right at 400 to 440 with every BG reading. Her periodic leg twitching has stopped. I am in a holding pattern at present that might last all the way until an appointment with an internal medicine specialist 6 days from now. If she needs insulin, it seems crazy to wait that long.

As a newbie, I'm not sure of forum etiquette and all that, but I think I might start a new post and re-state the history. As I re-read above, some of what I wrote frantically comes off confusing. So I'll try to be more crisp with describing the situation. And try to use some abbreviations, etc. that I'm seeing on the site to speak the language more.

I really do sincerely appreciate the comments/suggestions/etc.
(And am not at all trying to be jerky by starting new post. Just less confusing and more effective while still desperate for advice on the current course of action.)

 

Could you please update your spreadsheet with the test data since yesterday morning? As you may have guessed, we are very data driven here. I suspect she still needs insulin, as her spreadsheet to yesterday does not look like a cat ready to come off of insulin.

You don't need to start a new post.

 

Are you testing the BG levels since you stopped giving any insulin? I would recommend you do and if you could put them in the SS that would be helpful thanks.
It’s fine to start a new thread, if you want to but not needed . Just link this thread with your new thread for continuity by copying the URL bar at the top of the page and pasting it into the new thread.

Please make sure you test the urine daily for ketones and pop the result in the SS so we can see. It is really important you do this as lack of insulin can cause ketones to form.

 

Just a suggestion from my own experience - my cat is also very insulin sensitive and I dose her between 0.1 - 0.4 of Lantus. What I have found works fairly well for her is roughly an 18 hours cycle - with a 12 hour cycle (for my cat - and remember every cat is different) the Lantus depot kicks in too much and drops her too low, whereas with an 18 hour cycle the depot seems to be starting to wear out and doesn’t effect the next cycle too much, depending on her bg levels I sometimes can stretch it out to 24 hours or more and depending if I’m working it sometimes needs to be 24 hours. Sometimes I do a twelve hour cycle if her bg is a bit high but after a couple of cycles I find I need to drop back down to 18-24 hours. I find it real hard to be consistent with a cat who is so sensitive to insulin and find I just need to be flexible and make a decision with each blood test.

 

Thanks Myrtlesmum. Sounds like we're living each other's worlds here this past year. I did start a new thread and also got some nice additional advice there, too.
(http://www.felinediabetes.com/FDMB/...-insulin-and-instead-created-a-crisis.224007/)

For these low doses, do you happen to have any tips/tricks beyond eyeballing? I think I was pretty good for years eye-balling 0.4 to 0.75. But as she's gone down to 0.25 and 0.1, it's been much trickier.

 

Several ideas for you:
1. Using Calipers post here.
2. Make a Reference Gauge, instructions here.
3. Get inexpensive magnifiers at your local drugstore (chemist).
4. Or buy something like a headband magnifier, like the Optivisor, with the additional 2.5x magnifying loupe. Amazon but other places sell them. (I use mine for bird banding, ringing of birds to look more closely at the feathers and age the birds.)
5. Simple hand held 10x magnifier. I use one for looking more closely at plants. I have something like this.
6. Fine dosing link from the Lantus forum here. Scroll about 3/4 of the way down for pictures.

That's all I could think of off the top of my head.

Harder to do with fine doses but more important to make sure you got all the air bubbles out of the syringe. Draw a little extra, tap, tap tap with needle pointed up, squirt out excess.

 

I’ve tried everything Deb & Wink suggests in her post but in the end I have found it easier just to eyeball it using magnifying reading glasses and I use a syringe with half unit markings. I’ve found that the tiniest movements are really hard to manage between say 0.1-0.2. My attempt at using callipers for such tiny movements was disastrous and a complete waste of time and money. I do err on the side of caution though, I prefer to give too small a dose rather than too big and my no shoot number is anything under 150 - even if it means she will be a little higher in 12 hours.

 

@Myrtlesmum - it would be helpful for everyone to be able to see what you've been doing with respect to your managing your cat's FD if you are going to be offering suggestions to caregivers. You've no longer linked your spreadsheet which makes it very difficult to take your suggestions at anything other than face value. Personally, I'd like to see the data as there's something I may be able to learn.