Diabetes mellitus in cats – signs and what to do

Updated 2026-09-30 · 3 sources

Based on: PDSA, International Cat Care (iCatCare), Science for Animal Welfare (UFAW), Genetic Welfare Problems of Companion Animals

Contact a vet today

Contact your vet today if you think your cat has this – it can become serious. It is a condition where a cat cannot control its blood sugar properly.

What to do now

What you can do now

Contact your vet
Note when it started, how often it happens and what else you see
Take a photo or short video to show the vet
Keep fresh water available

Don't

Do not give any human medicine
Do not wait if it gets worse

What it is

Diabetes mellitus is a condition in which a cat’s body does not produce enough insulin or does not respond to insulin properly, leading to high blood glucose.^[2] Diabetes can have life-threatening complications, and low blood sugar is an emergency that can be fatal if left untreated.^[1]^[2]

Signs

Drinking more
Peeing more often
Weight loss
Increased appetite
An enlarged liver
Poor coat or fur changes
Weakness or low energy, especially in the back legs
Reduced appetite
Vomiting
Collapse

Causes and risk factors

Burmese cats may be more prone to diabetes
Norwegian Forest Cats have an increased risk

How a vet finds out

A vet may examine your cat and ask about their symptoms
A vet may take a detailed history and carry out a full check-up
Blood samples may be tested
Urine samples may be tested
Your vet may check for other illnesses or infections that could complicate treatment

How vets treat it

Diet change
Weight control or weight management
Insulin injections
Liquid or tablets if suitable

Breeds prone to this

Veterinary charities list these breeds as more likely than others to get this condition. Each breed page lists the inherited conditions documented in the breed.

What the experts say

“Overview. Diabetes prevents your cat being able to control their blood sugar levels. Blood sugars levels get very high, and at the same time their body becomes starved of energy. Symptoms include drinking and peeing more.”
— PDSA [1]

“Signs of diabetic ketoacidosis include vomiting, diarrhoea, anorexia (decrease or complete loss of appetite), and collapse – if you notice these signs with your cat, contact your veterinary team immediately.”
— International Cat Care (iCatCare) [2]

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

OkPaw asks a few quick questions about your pet and tells you in 30 seconds whether it can wait. Free on Google Play for Android.

OkPaw is on Android now – an iPhone version is on its way.

Common questions

What is diabetes mellitus in cats?

It is a condition caused when the body does not produce enough insulin or does not respond to insulin as it should, resulting in high blood glucose.^[2]

What signs can diabetes cause in cats?

Signs can include drinking and peeing more, weight loss, increased appetite, poor coat, weakness, reduced appetite, vomiting and collapse.^[1]^[2]

When should I contact a vet urgently?

Contact your veterinary team immediately if your cat has vomiting, diarrhoea, a decrease or complete loss of appetite, or collapse.^[2]

Sources

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

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