How can I get my diabetic cat regulated on insulin and when do I know to switch to a different insulin medication?

Original Question: Norton was diagnosed with diabetes in April 2018 and has been on Vetsulin starting from a 1 unit bid to 3 unit bids but it is still poorly regulated. At 3 units his sugar drops sharply and his glucose is too low 12 hours later to give him his next dose. Our vet is considering switching to ProZinc but I wonder what you might suggest? - Edith

How can I get my diabetic cat regulated on insulin and when do I know to switch to a different insulin medication? Aug 24, 2018

Hi Edith,

Thanks for your question.

This is a common problem that is frustrating to deal with. Getting a cat regulated on insulin can be a challenge and not all cats respond the same way to each type of insulin.

I can’t say right off the bat whether you’re on the right insulin or not. I would have to be the attending veterinarian and see the results of the blood glucose curves that they are doing. Based the information in your question, I’m going to assume that you are able to perform a blood glucose check at home which is great. Getting a cat regulated is all about consistently administering and checking the blood glucose curve.

The increase from 1 to 3 units is a big jump and there has to be sufficient time to get used to that new dose before performing and interpreting the next blood glucose curve. If you’re finding that the blood sugar is dropping too low for the next dose, then I would recommend you speak to your veterinarian about reducing the insulin dose so that you can give it consistently for a few weeks and then reassess with another blood glucose curve before making the decision to change medications.

Another critical point is how consistently your cat is eating and what diet they’re on. You’ll want to offer the food twice a day and not leave it out to graze on. It should also be a diabetic diet which has complex carbohydrates that take time to break down so that they release glucose into the bloodstream slowly over time between meals. This helps stabilize the blood sugar. I understand that your cat’s appetite may wax and wane while they’re being treated. You may feel the need to skip a dose of insulin if he doesn’t eat his meal, but by using the insulin, it will lower the blood sugar and this is one of the body’s signals to increase appetite. Even if the blood sugar is in the lower part of the normal¬†range, I recommend giving that insulin and monitoring closely, because if you keep skipping doses, it will be near impossible to get your cat regulated. If you can check blood glucose readings at home, you’ll be able to monitor and identify hypoglycemic events in advance but make sure you discuss this closely with your veterinarian if they agree and have them available in case of any concerns.

I hope this helps. Good luck.

Dr. Clayton Greenway

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