Switching from Caninsulin to Lantus

[RosettaSpice]

Our guy (14.5 y) has been on caninsulin since October 10 2025 first was 2 units then increased to 2.5 because of his high numbers. His numbers have been all over the place, some days being really good with 7/mmol at peak and 21.9/mmol at the highest just before a dose. We have both Lantus and a box of U-100 syringes coming and will be testing every 2 hours on Friday.

Do we give him the same dose as his Caninsulin?

Do we have to convert it to the new measurement for the U-100 syringe?

Any other suggestions or comments would be greatly appreciated!

 

[CORKY]

Welcome to FDMB
Caninsulin is a dog insulin this is can be a reason of BG numbers all over the place, this insulin hits hard and fast in a cat, so Is good you are switching to Lantus, Are you home testing or are you doing the curve at the vet? what are you feeding? diabetic cats need to have a diet of wet can or raw foods between 0-10% should be on a schedule, not grazing, kibbles are between 20-30% carbs, so if are feeding dry food, this can also be the reason, I do not give dosing advice, but I will tag a couple of members that can assist you with Lantus dosing, We are here for you.
@Wendy&Neko
@Sienne and Gabby (GA)

 

[RosettaSpice]

Thanks!

He’s on exclusively on wet food diet for diabetic cats (under 10% carbs) we do home testing for his glucose levels.

Our vet wanted him to stay on caninuslin and up the dose even more. We’ve decided to use Lantus on our own. Just looking for some advice on what to expect and how to accurately dose him at home, any suggestions or comments are appreciated!

 

[Sienne and Gabby (GA)]

You can make a unit-to-unit switch from Caninsulin to Lantus. Some members prefer to slightly reduce the dose if starting a new insulin. What is the current dose of insulin you're giving your cat?

It would be helpful for us to see a week or two of your home testing data. This is a link to a post on helping us to help you. It has instructions for setting up a spreadsheet. This will allow you to track your cat's progress and it will allow us to follow along as well.

 

[CORKY]

which wet food diet for diabetic? are you sure is 10%?, 99.9% of all supposed diet for diabetic or "prescribed" are very high in carbs , wet or dry, did you get it from the vet? this can be a reason of the BG being all over the place humans just regulate their diabetes with low carb foods, and insulin, can you post what is the name of the food and I can find out the carb content for you

 

[RosettaSpice]

You can make a unit-to-unit switch from Caninsulin to Lantus. Some members prefer to slightly reduce the dose if starting a new insulin. What is the current dose of insulin you're giving your cat?

It would be helpful for us to see a week or two of your home testing data. This is a link to a post on helping us to help you. It has instructions for setting up a spreadsheet. This will allow you to track your cat's progress and it will allow us to follow along as well.

He’s currently on 2.5 units of Caninsulin

 

[RosettaSpice]

He’s currently on 2.5 units of Caninsulin

He’s also eating Purina pro plan pate - dietetic management, and Fancy Feast low carb options suggested on these forums. He’s not eating any dry kibble at all, he eats only wet food as it’s easier on his teeth, and seems to be recommended in general.

Open to other suggestions for food, but regardless his number have been very low in a few rare instances, but generally quite high, especially before a shot, sometimes over 20.

 

[CORKY]

Is it in gravy? What’s the flavor??

 

[RosettaSpice]

Is it in gravy? What’s the flavor??

 

[CORKY]

Well according to the calculator and ingredients the dry matter carbs are 1.8% so is great here are the numbers