Diabetes in cats


  • Diabetes prevents your cat being able to control their blood sugar levels. Blood sugars levels get very high, but their body becomes starved of energy.
  • Symptoms include weight loss, drinking more, peeing more and low energy.
  • Diabetes is diagnosed with blood tests and urine samples.
  • Diabetes is treated with insulin injections and diet control.
  • The good news is, if your cat is treated quickly, they may improve enough to come off insulin injections and be controlled with diet alone.
  • Diabetes is most likely to occur in older, overweight, male cats.
  • Most cats develop type 2 diabetes, unlike dogs, who usually develop type 1.

Diabetes (in cats) explained

Blood sugar is normally used as energy by cells all around the body. Insulin (produced by the pancreas) is the hormone that feeds blood sugar into cells.

If a cat develops diabetes, their cells aren’t able take sugar in and become starved of energy. The pancreas continues to produce more and more insulin in an attempt to get sugar into cells, until eventually, it becomes exhausted and stops working. Cells around the body continue to starve, blood sugar levels rise abnormally high and the symptoms of diabetes develop.

Being obese increases a cat’s risk of developing diabetes, but other diseases (such as pancreatitis) and certain medicines can also cause it. Most cats get Type-2 diabetes, which many people understand as a condition that doesn’t need insulin injections. However, type two diabetes in cats is slightly different and can be treated with insulin and a well-controlled diet.

If a cat with diabetes is treated quickly, they have a good chance of improving enough to come off insulin injections, and be managed with diet alone. Keeping your cat slim and controlling what they eat is necessary for good diabetes management.


Diabetes is most common in male cats, overweight cats and cats over 10 years old. It causes the following symptoms:

cat drinking

Cats with diabetes tend to become very thirsty

When to contact your vet

Contact your vet if your cat is showing any of the symptoms listed above or you are worried they might have diabetes. The sooner your cat is diagnosed, the better their chance of recovery.

You know your cat best. If they don’t have the symptoms listed above but you are still concerned it’s always best to contact your vet.


Your vet will check your cat and ask about the symptoms you have noticed.

Blood samples. Your vet will take blood from your cat to check their blood sugar (glucose) level. They may also run some extra blood tests to rule out other problems.

Urine samples. Your vet will need a urine sample to check whether it contains sugar/glucose. It can be helpful to bring a urine sample to your appointment. Watch our video below on collecting a urine sample from your cat.

Sometimes, more than one set of blood and/or urine samples are needed to diagnose diabetes.

How to collect a urine sample from your cat


Treatment for diabetes in cats involves two main things:

  1. Insulin injections
  2. Diet control

Insulin injections

You will need to inject your cat with insulin every day (usually twice daily). Insulin injections lower your cat’s blood sugar levels by feeding it into cells for energy. Your vet will carefully work out how much insulin your cat needs and show you how to inject. It’s important to be accurate when injecting insulin, too much can cause low blood sugar (hypoglycaemia). You will need to give your cat their insulin injections 12 hours apart and at the same time everyday i.e. 7am & 7pm or 10am & 10pm.

Diet control

Controlling what your diabetic cat eats is a very important part of their treatment. The best food for your diabetic cat is a wet food that is high in protein and low in carbohydrate. Your vet will be able to advise you which food to choose. Cats need regular, small meals throughout the day and portion control is important to make sure they don’t get fat.


If your cat’s diabetes isn’t controlled, they may develop a condition called 'ketoacidosis’. If your cat develops ketoacidosis, they will become very poorly and need admitting to the veterinary hospital. Your vet will give them intensive treatment until they are well enough to come home. Ketoacidosis is a serious condition that often takes several days to recover from, it can lead to death if it’s not treated quickly.

Made a treatment mistake?

If you make a treatment mistake or something unexpected happens (i.e. they vomit or refuse food), don’t panic. Contact your vet for advice. Treating a diabetic cat requires teamwork between you and your veterinary practice – they will always be on the end of the phone to give you advice, support and arrange regular check-ups for your cat.

If you leave your cat’s diabetes untreated, it will cause suffering, severe illness and eventually be fatal.

Low blood sugar (hypo)

Having low blood sugar is an emergency, it can be fatal if it’s left untreated.

Low blood sugar may develop if your cat has:

  • Had too much insulin
  • Eaten less than usual
  • Vomited
  • Refused food.

If your cat is having a ‘hypo’, you may notice that they are weak, wobbly, confused or twitchy. They may appear very hungry, vomit, have a seizure or even collapse.

Low blood sugar is an emergency – rub something sugary into your cat’s gums (honey/sugar) and contact your vet immediately for an emergency appointment.

Ongoing care

Regular check-ups

Your cat will need regular check-ups so that their condition and insulin dose can be monitored. After having insulin for a while, some cats improve enough to come off their injections and be treated with food alone. If your cat continues having insulin injections when they don’t need them, they could develop low blood sugar.

Weight control

Keeping your cat slim and active will make their diabetes much easier to control.


Keep your cat’s food and insulin routine the same every day to keep their blood sugar levels steady.


The outlook for most diabetic cats is good if they are treated quickly and respond well. Some cats need to stay on insulin for the rest of their lives but many can come off their insulin injections and be managed with food alone.

Sadly, for some cats (especially those with other illnesses) diabetes proves extremely difficult to control. If your cat has a complicated case of diabetes and it is causing them to suffer, it may be necessary to consider the difficult decision of putting them to sleep.


Not all cases of diabetes can be prevented, but you can reduce your cat’s chances of developing the condition by feeding them a good quality diet, keeping them slim and encouraging them to stay active.

Costs and practicalities

If your cat has been diagnosed with diabetes and you’re concerned about the cost and practicalities of looking after them, don’t worry, you’re not alone - your vet practice will give you plenty of support.

For some owners, the commitment or cost of caring for a diabetic cat is too much. It’s very important to speak openly to your vet about what you think is right for your cat, your lifestyle, finances, and how you’ll think you’ll cope.

Treating a diabetic cat can become very expensive. Consider insuring your cat as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them.

Published: June 2019

Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.