Hello and thanks for the great resource! Our cat, Sally, was newly diagnosed in July of 2019. We immediately put her on a homemade raw chicken-based carb-free diet. For about a year, she was very well-regulated on PZI, but her numbers began to rise this autumn; by the end of October of 2020, she was getting about ten units of insulin per day. Hoping for better results, we switched her to Lantus on November 11th 2020. We cautiously started her on a relatively low dose of 1.5 units 2x per day, but have gradually increased that to 5 units 2x per day. We realize that Lantus takes time to build up in the body, but she has been on Lantus for over two weeks now and we have seen no improvement in her numbers compared to the numbers she had on PZI just prior to switching to Lantus. Any thoughts on this?
Welcome Just stopping by and bumping your post. Looks like you have your Spreadsheet set up Have you chose a dosing method? It would also be great to set up a signature with helpful info to help us help you at a glance. There are a few high dose conditions that are considered once a kitty is above 5 units, (acromegaly or IAA) which can have different treatment options to help. Also tagging someone who might be able to better advise @Wendy&Neko
Usually, we take into consideration the dose the cat was getting when we switch insulin's. By dropping from 10U down to 1.5, you usually end up wasting a lot of time going back up. We usually hold the dose for at least 6 cycles (on Tight Regulation) and there are several times when you increased sooner, but that's probably OK in this situation. We occasionally will recommend "fast-tracking" and increasing every 4 cycles. I'd probably go up to 5.5 U tomorrow but it will be important for you to get at least 1 mid-cycle test on every AM cycle and at least 1 "before bed" test on every PM cycle from now on, especially if we fast track. It may be a good idea to be thinking about getting him tested for acromegaly and IAA. They are special blood tests run only at MSU so your vet would have to pull the blood to send to them for testing. We suggest testing when a cat gets over 6U of insulin.
Do you have any data for Sally on PZI on 10 units? Just wondering if you should jump up closer to the PZI dose. Depending on what she looked like on that dose, we would have suggested the same dose of Lantus. Though truth be told, I would have suggested going to Levemir. Lantus has an acid base that can sting at higher doses. Plus Levemir is often a better choice for higher dose cats, with a bit better duration. If you are going to increase every 3 days, you really need to get a second test each and every cycle. That includes the night time, even a +2 or +3 is good enough. Many cats go lower at night and we dose by those lows. Depending where you live, the tests for acromegaly is either the Royal Veterinary College in the UK or Michigan State University in the US. We suggest the testing to anyone when their cat gets to 6 units, though it's also possible to have those conditions with lower doses. Just over that amount, it's much more likely.
Thanks Chris and China. Agreed on the 1.5 being too low to start, our vet actually recommended starting at 1.0... We definitely increased sooner than recommended, but she basically never even got below 200, so we figured we had a decent safety margin. One thing to note is that she has a ravenous appetite (always had). When she first was diagnosed she was 14+ lbs. We cut her food to 3.5 oz /day and eventually got her down to 12 lbs. She's now at 5.25 oz per day plus a chicken bone for a snack. Full blood work, including regular and special thyroid tests, a month ago. Some things were marginal, but all within normal ranges. I'll ask about the other tests (need to read up on them). It's so frustrating because for like 8 months she was 135, dose 3.2 units, low 75, repeat. Every day. Then she just started drifting higher and higher and we kept chasing it with increased doses.
Wendy and Neko, It was 5 units each dose of pzi (we even tried dosing about 3.3 units every 8 hours for a week or so without any better results). I'll also look into levemir. Thanks!
Good to know. Then you would have started at 5 units. Don't worry about the Levemir just yet, just pay attention to see if Sally reacts to the shot. Not all cats do, but a number do as they get up there in Lantus dose. Neko used to walk away as I was shooting sometimes. The ravenous appetite can be a clue. Acromegaly is caused by a benign tumour on the pituitary gland. That sends out excess growth hormone - think teenage boy appetite! Since you only have 3 cycles out of 6 with a second test test during the cycle, I'd do a couple more cycles at 5.0 with some secondary tests, just to make sure we aren't missing anything. Then if no blues, up to 5.5 units.
