Diabetes Mellitus in Cats 

The pancreas sits near the stomach, it is responsible for producing insulin. Insulin is a hormone responsible for controlling blood sugar levels and delivering glucose to cells. 


When a cat develops diabetes mellitus the cells responsible for producing insulin are not able to do their job effectively. 


Clinical signs of diabetes in cats 


  • Increased thirst (drinking more than normal) 

  • Increased urination 

  • Weight loss 

  • Lethargy 


If your cat presents with these clinical signs, your vet may suspect diabetes mellitus. They will take a blood sample and urinary samples to achieve a diagnosis. Blood glucose in a cat with diabetes mellitus will be persistently high and there will also be glucose in their urine. Definitive diagnosis of diabetes mellitus in cats may require blood to be taken to send to the lab, this can take a little longer to get the results. 


Treatment of diabetes mellitus in cats involves a combination of diet control and regular insulin injections. 


Diet control in cats with diabetes mellitus is important, your veterinarian will advise a specific diet which can help control a cat's blood sugar levels. A diet which is low in carbohydrate and high in protein will help prevent glucose being absorbed from the gut. 


Insulin injections generally have to be given twice a day in cats with diabetes mellitus, 12 hours apart. This has to be done accurately, if cats are given too much insulin their blood sugar can go too low (hypoglycaemia) and this can be dangerous. 


Some cats can be managed through diet alone, this is case specific, and you should make regular check-up appointments with your vet. 


If a cat is given too much insulin, their blood sugar may drop too low. This is called hypoglycaemia. Always check if the dose of insulin is correct before giving. 

Signs of hypoglycemia 


  • Wobbly gait 

  • Weakness 

  • Lethargy 

  • Shaking 


This is an emergency and you should contact your vet immediately.

Get a printable version here

This advice is for UK pets only.Written by vets. Please always seek advice from your own veterinary surgeon if you have concerns about your animal, never try to treat an animal yourself or give any medication without veterinary supervision.