Cat Diabetes: Signs, Diagnosis & How to Manage It

Why cats get it

Diabetes mellitus happens when a cat's body doesn't make enough insulin, or can't use the insulin it makes properly, so glucose builds up in the blood instead of fueling cells. It tends to show up in middle-aged to older cats, and it's more common in males and in cats carrying extra weight. Cornell's feline health center puts the prevalence at roughly 1 in 100 to 1 in 500 cats.^[1] Obesity is the single biggest controllable risk factor, which is why a diagnosed cat's treatment almost always starts with food and weight management, not just medication.^[1][2]

Signs to watch for

The classic early signs are easy to miss because they build slowly:

• Drinking more. You're refilling the water bowl more often.
• Peeing more. Bigger clumps in the litter box, or accidents outside it.
• Weight loss with a normal (or bigger) appetite. The body can't use the food, so it starts burning fat and muscle.
• Low energy and a dull, unkempt coat.

Later, some diabetic cats develop nerve damage and start walking on their hocks instead of their toes — a flat-footed stance that's a strong signal to see a vet soon.^[1][2]

How it's diagnosed

A vet checks blood glucose and tests urine for glucose. Here's the catch: stress alone can spike a cat's blood sugar at the clinic, so one high reading isn't enough on its own. To get a reliable answer, vets often run a fructosamine test (a longer-range average of blood sugar) or do a glucose curve — several readings over the course of a day.^[3]

Treatment & diet

Most diabetic cats need insulin injections, usually once or twice a day at home, plus a diet change. The insulin types used most often in cats are long-acting options like glargine or protamine zinc insulin (PZI).^[3] Diet matters too: diabetic cats generally do better on a high-protein, low-carbohydrate food, and getting extra weight off makes insulin work better.^[2]

Treatment also means monitoring at home — many owners learn to check blood glucose with a small glucometer — and regular vet rechecks to adjust the dose. It's a commitment, but once you settle into the routine, it becomes just another part of the day.^[2][3]

Can it go into remission?

Yes — and this is the part that surprises people. A meaningful share of diabetic cats go into remission, meaning their blood sugar normalizes and they no longer need insulin. Remission is most likely when the disease is caught early, the cat loses weight, and the diet is switched to a low-carb food.^[1][3] It isn't a guarantee, and it doesn't mean the disease is permanently cured — some cats relapse later — but it's a realistic goal worth aiming for with your vet's help.

FAQ

Is diabetes curable in cats?

Not exactly "cured," but it can go into remission, where a cat no longer needs insulin. That's different from being gone for good — some cats relapse — so even a cat in remission stays on a careful diet and regular vet checks.

Do all diabetic cats need insulin?

Most do, at least at first. A few cats diagnosed very early may be managed with diet and weight loss alone, but that's a call for your vet — stopping or skipping insulin without guidance can be dangerous.

What's the best diet for a diabetic cat?

In general, a high-protein, low-carbohydrate food — and portion control to shed excess weight. Don't change food on your own, though; the timing matters alongside insulin dosing, so coordinate with your vet.