Diabetes mellitus in cats

April 09, 2025

Diabetes is a common illness in middle-aged and older cats. It means they can’t control their blood sugar levels. It affects around 1 in 230 cats or 0.43% of the population. There isn’t a cure for diabetes, but treatment with insulin and a special diet control the condition. Early identification and treatment ensures the best outcomes for cats with diabetes. Untreated or uncontrolled diabetes causes life-threatening illness.

Causes

Type 1 diabetes 
  • Rare in cats

  • The body is not able to produce enough insulin 

  • Causes: inherited or from chronic pancreatitis

Type 2 diabetes
  • Accounts for over 90% of diabetes in cats

  • The body can’t use the insulin that is produced

  • Possible causes include: other illnesses, certain medications (steroids), obesity

Risk

Although any cat can develop diabetes, some things do increase their risk:

  • Sex: male cats

  • Age: over 8 years old

  • Overweight (obese) and inactive

  • Diet: eating dry food

  • Breed: Burmese cats have an inherited risk of diabetes

  • Other illnesses - chronic or recurrent Pancreatitis, acromegaly (having too much ‘growth hormone’)

  • Certain medications - steroid anti-inflammatory medicines (for feline asthma or skin allergies). Steroid hormone treatments (for skin disease or behaviour problems)

Complications

Untreated or poorly-controlled diabetes leads to diabetic ketoacidosis (DKA). This is a much more severe and life-threatening illness.

Having too much insulin for the amount of sugar in the blood can lead to dangerously-low blood sugar levels, called hypoglycaemia.

Symptoms

  • Drinking more 

  • Peeing more

  • Losing weight and muscle

  • Eating more

  • Sleeping more

  • Developing a poorer coat

  • Walking ‘crouched’ on back legs

Conditions more common in diabetic cats:
  • Cystitis: bladder infection and inflammation

  • Cataracts and blindness

  • Recurrent or repeated infections due to a weakened immune system

Diagnosis 

  • A physical exam

  • Urine tests

  • Blood tests

Treatment

  • Insulin injections every 12 hours are needed to control blood glucose. 

  • Diet planning and managing body weight.

  • Antibiotics if infections are present.

  • Ongoing monitoring of glucose levels in the urine and blood tests are extremely important. This will be more frequent in the beginning, until the levels are more stable. 

How to help at home

Caring successfully for your diabetic cat means keeping to a regular routine of feeding, insulin treatment and weight management.

  • Ensure your cat gets their insulin injections at the correct dose and time.

  • Feed a prescription diet for diabetes regularly throughout the day. Hills m/d is ideal.

  • Check your cat’s weight regularly and keep them slim to make control easier.

  • Keep up to date with preventive care - vaccination, worming and flea treatments.

  • Identify and treat other health problems promptly.

  • Attending regular check-ups with a vet to make sure that diabetes is under control.

What to expect

Most cats live a full, happy life on insulin treatment. Caring successfully for a diabetic cat is a big commitment. Talk everything through with your vet before starting your cat’s treatment.

Serious complications, like diabetic ketoacidosis, are more likely as they get older and develop other illnesses. 

Prevention

Burmese cats have an inherited risk of diabetes, which can’t be prevented. However, obesity predisposes all cats to diabetes.

Reduce your cat's risk of diabetes by:

  • Feeding a well-balanced diet that’s suitable for their age and lifestyle. 

  • Keeping your cat at a healthy weight 

Are my other pets or family at risk?

  • Diabetes affects individual cats. It won’t spread to other animals or humans.

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