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Diabetes in dogs

Isolated dog


  • A dog with diabetes isn’t able to control their blood sugar level.
  • They aren’t able to produce enough insulin which means their blood sugar level gets very high (like type 1 diabetes in people).
  • Diabetes requires lifelong treatment, it can’t be cured.
  • Treatment involves insulin injections, careful feeding and exercise control.
  • Owning a diabetic dog is a big commitment but with the right treatment and careful monitoring it’s possible for your dog to live a long, happy life.

Please take a look at our three videos:

  1. My dog has diabetes. What next?
  2. Treating your diabetic dog
  3. How to: inject your diabetic dog with insulin

What is diabetes?

Diabetes is a condition that prevents insulin being produced. Dogs that can’t produce enough insulin aren’t able to control their blood sugar level.

Normally, sugar travels from food, via the stomach into the blood where it’s ‘fed’ into cells all around the body to give them energy (muscle and brain cells for example). Diabetic dogs don’t produce enough insulin to ‘feed’ sugar into their cells so it stays in the blood and builds to dangerously high levels while their cells starve.

In the short term, diabetes causes increased thirst and weight and without treatment, it starts to affect the heart, kidneys, eyes, nerves and blood vessels. If diabetes is left untreated, serious illness is likely to develop which often leads to death.

Illustration showing how diabetes works

Diabetes is a condition that prevents insulin being produced (click to expand image)


A more serious complication of diabetes is low blood sugar (often called a hypo). This is a life threatening condition, symptoms include:

  • Vomiting
  • Diarrhoea
  • Appearing unsteady (as if they are drunk)
  • Collapse
  • Breath that smells sweet (like nail polish remover or pear drops)

These symptoms are an emergency - contact your vet immediately.


Diabetes is most commonly caused by the body attacking and destroying its own insulin cells (mistaking them for something else). Some dogs develop diabetes after suffering from a condition called pancreatitis. It’s unlikely to be anything you have done wrong.


Diabetes can be diagnosed with urine and blood tests.

If you’re worried your dog may have diabetes collect a fresh urine sample to their vet appointment.


Diabetes is a condition that needs lifelong treatment, it can’t be cured. However, well-controlled diabetic dogs often live a long, happy life. Once treatment has started, your dog is likely to show a big improvement and start to feel better within a week or two.

Treating diabetes involves:

  • Insulin injections
  • Controlled feeding
  • Controlled exercise.

Insulin injections

  • Insulin injections need to be given twice daily to bring blood sugars down.
  • It’s important that insulin is given at the same time, twelve hours apart, every day – for example 7am and 7pm or 10am and 10pm.
  • Insulin injections should be given within an hour of feeding (ideally straight after your dog eats).
  • Your vet will show you how much insulin to give and how to inject.
  • Injecting may seem scary at first but it’s something you and your dog will get used to very quickly. The needles are so tiny some dogs don’t even notice!


  • To keep blood sugar levels as steady as possible, you will need to feed your dog a set amount every 12 hours.
  • Keep their food brand the same, each food has a different amount of sugar and energy in it. Certain foods are better for diabetic dogs because they release sugars slowly – speak to your vet about which food is best for your dog.
  • Never feed them in between meals – extra food will cause a rise in their blood sugar and could make them unwell.
  • Use lots of fuss and play as a reward instead of feeding treats.


  • Dogs with diabetes need to be given a set amount of exercise, at the same time each day.
  • Going for a much longer walk (at the weekend for example) could cause blood sugars to drop dangerously low.


  • If you have a female diabetic dog your vet is likely to advise spaying (neutering). Changes during a season can make diabetes hard to control.

What if I make a mistake?

Treating a diabetic dog can feel nerve wracking to begin with; most owners worry about making a mistake when injecting or about whether their dog will eat all their food.

So, what could go wrong?

  • You might accidentally inject too much or too little insulin.
  • Some may squirt out as you inject.
  • Your insulin might ‘go off’ if it’s been left out the fridge.
  • Your dog might not eat all their food or they might steal some extra food.
  • They may vomit after they’ve eaten.

If you’re faced with any of these situations, call your vet practice for advice. Managing diabetes is a partnership between you and your vet – they will always be on the end of the phone to help and give advice.

Low blood sugar (hypoglycaemia)

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

Low blood sugar may develop if your dog has:

  • Had too much insulin
  • Done more exercise than usual
  • Eaten less than usual
  • Vomited.

If your dog is having a ‘hypo’, you may notice that they are wobbly, ‘spaced-out’ or twitchy. They may appear very hungry, vomit or even collapse.

It’s a good idea to carry a small sachet of something sugary everywhere you go with a diabetic dog.


If you think your dog has low blood sugar:

  • Rub something very sugary such as honey or jam onto their gums
  • Contact your vet immediately for an emergency appointment.

Ongoing care

Keep your dog’s routine the same

  • Keep your dog’s routine the same every day to help keep their blood sugar steady.
  • Remember, blood sugars are increased by food and decreased by insulin and exercise.

Weight control

Regular monitoring

  • It’s important to have your dog checked as regularly as your vet suggests. This is to make sure their diabetes is staying well controlled.
  • Look out for cataracts (cloudy eyes) – they’re a very common complication of diabetes (even in well managed diabetics). Cataracts cause vision loss and eventually blindness. Amazingly most dogs cope very well vision loss but if your dog is struggling, cataracts can be removed at specialist eye hospitals.


  • A well-managed dog that responds well to treatment has a good chance of living a long, happy life.
  • It’s important to understand that diabetes is a lifelong condition and that caring for a diabetic dog is a big commitment. A strict routine, regular vet visits and lifestyle changes will be necessary.

When to contact your vet

Book an appointment with your vet if you notice symptoms of diabetes in your dog.

If you notice the symptoms of a hypo, this is an emergency and your dog will need to see a vet straight away.

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

Costs and practicalities

If you’re worried about the cost or practicalities of looking after your diabetic dog, 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 dog is too much. It’s very important to speak openly to your vet about what you think is right for your dog, your lifestyle, finances, and how you’ll think you’ll cope.

Treating a diabetic dog can cost thousands of pounds over their lifetime. Consider insuring your dog 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.


Preventing diabetes isn’t really possible, however you can take some sensible steps to ensure that your dog stays as healthy as possible throughout their lifetime.

Published: December 2018

PetWise Pet Health Hub – brought to you thanks to support from players of People’s Postcode Lottery 

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

Illustrations by Samantha Elmhurst