Glossary

Diabetes mellitus

A disease in which a cat's body cannot make or use insulin properly, so blood sugar stays too high.

Also called: feline diabetes, diabetes in cats, sugar diabetes, diabetic cat

Diabetes mellitus develops when the pancreas does not make enough insulin, or the body responds poorly to it. Insulin moves sugar from the blood into cells. Without it, sugar builds up in the blood and spills into the urine. Most diabetic cats have a form similar to type 2 diabetes in people. Risk factors include obesity, age, being male, inactivity and some medicines. Chronic pancreatitis may also play a role.

Early signs are drinking and urinating more, a big appetite with weight loss, and lethargy. Some cats walk with their hocks low to the ground, a sign of nerve damage. A diabetic cat that vomits, stops eating, breathes fast or becomes weak or collapses may have ketoacidosis and needs emergency care.

A vet confirms diabetes through repeated high blood sugar along with sugar in the urine, and may test for other disease. Treatment usually means insulin injections given at home, a diet chosen by the vet and regular monitoring. With early, careful treatment and weight loss, some cats go into remission and no longer need insulin, though they remain at risk of relapse. Never change insulin on your own. Ask your vet how to give injections, recognize low blood sugar and keep records.

Last reviewed November 7, 2026

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Related terms

Obesity Excess body fat that harms a cat's health, raising the risk of diabetes, arthritis and urinary disease. Body condition score A hands-on rating of how lean or fat a cat is, on a scale such as 1 to 9, used by vets because weight alone can mislead. Pancreatitis Inflammation of the pancreas, a hard-to-spot illness in cats that often causes only tiredness and loss of appetite. Urinalysis A set of tests on a cat's urine that reveals kidney function, infection, crystals, diabetes and more. Blood panel A set of blood tests that counts cells and measures chemicals to show how a cat's organs are working. Hepatic lipidosis A serious liver disease in which fat builds up in liver cells after a cat stops eating, most often in overweight cats.

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