Lantus is an excellent insulin for cats. It's likely you didn't see the results you were hoping for only because you either didn't go up enough in dose, didn't catch the lower numbers when the curve with the vet was scheduled, or because of the dry food. It's not that it wouldn't work for him - really. If you know how to use it and how to adjust the doses, it works. You don't need to worry about acromegaly either - you have dry food in the picture and that completely explains the dose. In fact, the dose is probably not high enough to compensate for the dry food.
We know from people's experiments that dry food can cause very high numbers - even just 3 pieces of kibble can raise a cat's blood sugar more than 100 points and it can last for a day. Here is the spreadsheet of the cat I was mentioning.
Scooter lives in a household of 13 cats. Linda was pretty certain he wasn't eating the dry food because he didn't seem interested in it. She did all the right things - she got his teeth cleaned, she tried switching him from Lantus to Levemir, she fed the other cats their dry food separately from Scooter, etc. When everything else had been exhausted, she took the dry food out of the house. Turned out that Mr. Scooter had been sneaking crunchies when she wasn't looking! :lol:
He went from 5.5u to off of insulin. The day before the dry food disappeared he was in the 350's. After the dry food went away and he settled down from bouncing from the low numbers, he was in the 50's. That's the power of dry food. The day she took away the dry food was a harrowing day - she was testing every 30 minutes or so and his blood sugar wasn't coming up and staying up. But the outcome was no more insulin for Scooter.
Scooter's 5.5u on Dry Food to OTJ on Feb 19, 2014
You can scan down his spreadsheet and see that two more times he got into dry food and his blood sugar went up to 400+ from it.
Dry food can have as much as 50% carbs. It's pretty impossible to get a cat's pancreas to heal and for the cat to go off of insulin if they are eating dry food.
However, making the transition from dry food to only low carb canned food has to be done carefully. As you withdraw the excessive carbs, the insulin dose will be too large. Do it gradually while you are hometesting so you can reduce his insulin.
We can help you get going on the hometesting. It overwhelms everyone at the beginning, but once you learn how it's no harder than brushing your teeth. When I was talking on the phone while testing punkin, I realized I'd made it. It had become easy when I never thought it would be. The first 2 weeks of testing him I was dragging him by his arms out from under the furniture, hoping i didn't dislocate his arms! Then I had to wrap him in a towel and pin down his front legs so he wouldn't escape. But after 2 weeks he gave up, his ears bled every time, and I knew we were on our way. You'll get there too.
Newly diagnosed cats have a huge advantage in being able to heal and go off of insulin if they get regulated asap. Time is of the essence. Make the most of the advantage.
edited to add: here is an excellent site with tips on
Feeding your Cat including a link (see the right hand column or slide down the page) on Transitioning your Dry Food Addict to Canned Food.