Diabetes means your cat's body no longer responds to insulin properly, or no longer makes enough of it, so sugar builds up in the blood and spills into the urine. It is treated with insulin injections or, for some newly diagnosed cats, a medicine given by mouth once a day. The American Animal Hospital Association's 2026 guideline for cats puts the average remission rate in the United States at about 30%, where remission means normal blood sugar for more than four weeks with no medicine.
Insulin is the hormone that moves sugar from the blood into the body's cells. Cornell's Feline Health Center says most diabetic cats have the kind in which the cells stop responding to insulin, called type 2 in people. The American Animal Hospital Association says the high sugar then harms the cells that make insulin, and that in some cats those cells recover and treatment can stop.
Cornell estimates that between 1 in 100 and 1 in 500 cats are diagnosed with diabetes in their lifetime. It names obesity, age, inactivity, being male and steroid medicines as the main risks, and says obese cats are up to four times more likely to get it.
Cornell says the two signs owners notice most are weight loss despite a good appetite, and more drinking and urinating. The guideline explains the second: once blood sugar passes about 250 to 300 milligrams per deciliter, the kidneys can no longer hold it back, and the sugar goes out in the urine. It adds tiredness and an unkempt coat, and warns that slow changes go unnoticed.
Rarely, Cornell says, uncontrolled diabetes damages the nerves in the back legs, so the cat walks flat on its back feet, with the hocks on or near the ground.
| Test | What it measures | What the result tells the vet |
|---|---|---|
| Blood glucose | The sugar in the blood at that moment. | It is high in diabetes, but Cornell says stress alone raises it in a cat for a short time, so one high reading at the clinic is not proof. |
| Urine glucose | Whether sugar is spilling into the urine. | The guideline counts high blood sugar or sugar in the urine as evidence when it is found more than once, in a calm or home setting. |
| Fructosamine | The average blood sugar of the last week or two. | Cornell says the stress of the visit does not affect it. |
| Ketones, in blood or urine | What the body makes when it burns fat for energy. | The guideline wants blood ketones measured in every newly diagnosed cat, because the result may change the choice of treatment. |
| Blood count, chemistry, urine, thyroid T4 and blood pressure | The rest of the cat's health. | They look for conditions that stop insulin from working, such as pancreatitis, an overactive thyroid or kidney disease. |
More on the samples: blood tests and urine samples.
For a cat on treatment, the guideline no longer recommends day-long glucose curves at the clinic. It prefers a glucose sensor worn on the skin at home, and says even two or three days of readings are useful. Its rule is short.
It adds that a reading over 300 is not an emergency in a cat.
Insulin is injected under the skin, usually every 12 hours. Two insulins are FDA-approved for cats, ProZinc and Vetsulin. The guideline says the usual choices are ProZinc and glargine, an insulin made for people, and that Vetsulin is not routinely a first choice because it does not last as long. Both approved insulins are U-40, and both labels warn that any syringe other than a U-40 syringe gives the wrong dose. How the syringes differ is on Diabetes in dogs.
Never raise the dose on your own. The guideline lets owners lower or skip a dose when they see signs of low blood sugar. If a cat on insulin will not eat, the ProZinc owner sheet says not to give the dose, and the guideline says to skip or reduce it and to contact the vet.
Two medicines are given by mouth once a day: Bexacat, a tablet the FDA approved in December 2022, and Senvelgo, a liquid. The FDA says they are not insulin. They lower blood sugar by sending it out through the kidneys, and they only suit a cat that still makes some insulin. The FDA rules them out for a cat that has ever had insulin, that is not eating, is dehydrated or low in energy, or that has kidney, liver or pancreas disease.
Their serious risk is ketoacidosis, which on these medicines can happen while the blood sugar looks normal. The guideline puts it at 5 to 7% of treated cats, the same as with insulin, usually within the first two weeks. If the cat eats less, vomits, has diarrhea or seems weak, the FDA says to stop the medicine and contact the vet immediately.
For food, the guideline prefers canned to dry, high in protein and low in carbohydrate, with slow weight loss for an obese cat.
Some things are not worth paying for. The guideline does not recommend glucose meters made for people or a sensor worn all the time, and sees no reason for a sensor on a cat that takes Bexacat or Senvelgo.
The guideline's summary sheet says cats with diabetes can live comfortably with it for the rest of their lives. Of the cats that reach remission, the guideline says about a quarter do so within two to three months and most within six. Cornell says a cat that is not in remission after six months will almost certainly need insulin for life.
Remission is not the end of the disease. The guideline says relapse is common, and recommends careful weight control, a canned low-carbohydrate diet and a check every six months.
CareCredit publishes national averages for cats from a 2025 to 2026 cost study by Synchrony: $74 for a diabetes consultation, $47 a month for insulin, $35 for a blood glucose test and $54 for a urine test. More figures are on What does a vet bill cost? Help is on When you cannot pay the vet bill.
There are two, and both can kill.
Low blood sugar happens to cats on insulin. The guideline's signs are sleepiness, strange behavior, a wobbly walk, weakness, tremors and seizures. If the cat is awake, feed it. If it barely responds or is trembling, rub corn syrup onto its gums with a cotton swab or a syringe, never with your fingers, and go to the vet. The guideline says one teaspoon and the insulin labels about a tablespoon. The guideline also says not to swap in honey or pancake syrup for a cat.
Ketoacidosis happens when the body burns fat because it cannot use sugar. The FDA's signs are breath that smells sweet or worse than usual, not eating or drinking, unusual quietness, vomiting, weakness, trouble breathing and collapse. Go now, and tell the clinic which diabetes medicine the cat takes.
All the signs are on Cats: is this an emergency?
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Sources read on 2 October 2026; every number is as the source gives it.