Diabetes in dogs


  • Dogs with diabetes can't produce insulin, which causes their blood sugar levels to become dangerously high.
  • Symptoms of diabetes in dogs include weight loss, increased thirst and low energy.
  • Fortunately, most dogs with diabetes can be well managed with lifelong insulin injections (as well as 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 diabetic dogs to live a long, happy life.

What is diabetes?

Diabetes is a condition that develops when a dog can’t produce enough insulin to control their blood sugar level (causing it to become dangerously high). It’s usually caused when the body attacks and destroys its own insulin producing cells (mistaking them for something else), but can also sometimes develop after suffering from pancreatitis.

In a healthy dog, sugars travel from their food, to their stomach and then into their blood (where they are called ‘blood sugars’). Blood sugars then then provide energy to cells all around the body (such as muscle and brain). Insulin is crucial to get sugar into cells, so in diabetic dogs, who don’t produce enough of it, blood sugars stay in the blood and build up to dangerously high levels (while their cells starve).

Diabetes is an extremely serious condition that without treatment, can often lead to death.

Illustration showing how diabetes works

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


The first symptoms of diabetes in dogs tend to include:

Left untreated, diabetes can lead to a much more serious condition called ‘diabetic ketoacidosis’ (DKA). DKA is when a product called ketones builds up in the body if cells aren’t able to get the energy from blood sugars. Ketones in large number are extremely dangerous and cause the following symptoms:

Symptoms of DKA are an emergency - if you notice them, contact your vet immediately, especially if your pet has recently had other symptoms of diabetes (or has already been diagnosed).

When to contact your vet

Get in touch with your vet if you notice symptoms of diabetes in your dog. Contact your vet straight away if you notice the symptoms of a hypo or diabetic ketoacidosis, they are both an emergency.

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.


Diabetes can be diagnosed by urine and blood tests. If you’re worried your dog may have diabetes collect a fresh urine sample to take to their vet appointment.


Diabetes is a condition that needs lifelong treatment and a lot of commitment, especially in the early stages as your dog is stabilised. However, once treatment has started, your dog is likely to start to feel much better within a week or two.

Treating diabetes involves:

Insulin injections

Insulin injections need to be given twice a day, every day, at set times, 12-hours apart (for example, 7am & 7pm or 10am & 10pm). They should be given within an hour of feeding (ideally just before, or at the same time as your dog eats). Your vet will show you how much insulin to give and how to inject it. Injecting may seem scary at first but it’s something you (and your dog) will quickly get used to, the needles are so small that some dogs don’t even notice their injections! If you’re unsure about anything to do with injecting, speak to your vet for advice.


To keep your dog’s blood sugar levels as steady as possible, you will need to feed them twice a day, at set times, 12 hours apart. They will need the same amount and type of food every day and should never have treats in between meals (because the extra food will cause a rise in blood sugar). Certain foods are better for diabetic dogs because they release sugars slowly – speak to your vet about which food is best for your dog. Use lots of fuss and play as a reward instead of feeding treats


Exercise uses up blood sugars so diabetic dogs need a set amount, at set times each day. Suddenly increasing or decreasing your dog’s exercise could cause their blood sugars to rise/fall.

Possible complications

Treating a diabetic dog can feel daunting to begin with, and most owners worry about injecting, making a mistake or feeding incorrectly. So, what could go wrong?

  • You might accidentally inject too much or too little insulin.
  • Insulin 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.
  • Your dog might 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 (also known as a hypo), can develop if your dog has too much insulin, too much exercise, or not enough food. Having low blood sugar is an emergency and can be fatal if it’s left untreated. Symptoms tend to include vomiting, becoming wobbly, spaced-out, vacant, very hungry, twitchy and even collapse. If your dog is having a hypo, they need to be given sugar quickly, so it’s a good idea to carry a small sachet of something sugary everywhere you go (such as a liquid glucose sachet designed for runners).

Emergency first aid for a hypo (low blood sugar)

  • Rub something very sugary such as honey or jam onto your dog’s gums (be careful not to get bitten)
  • Contact your vet immediately for an emergency appointment

Ongoing care

Keep a routine

  • Give your dog a daily routine that stays the same each day to keep their blood sugars steady.
  • Remember, insulin and exercise decreases blood sugar, and food increases it.

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.


Most well managed diabetic dogs that respond to treatment have long, happy lives. However, it’s important to be aware that treatment takes a lot of hard work, commitment, lifestyle changes, a strict routine and regular vet visits.

Costs and practicalities

Treating a diabetic dog takes a lot of commitment and hard work and can cost thousands of pounds over their lifetime. If you’re worried about the costs or practicalities of looking after your diabetic dog, speak openly to your vet about your concerns. They will talk to you about what you think is right for your dog, your lifestyle, finances, and how you’ll think you’ll cope - your vet practice will be able to give you plenty of support in making the right decision for your dog. For some owners, the commitment or cost of caring for a diabetic dog is too much and sadly, in this scenario, euthanasia is often the kindest option.

Consider taking out dog insurance as soon as you bring your dog home, before any signs of illness start. This will give you peace of mind that you have some financial support if they ever become unwell. 


Should I have my diabetic dog speyed?

Yes, if you have a female diabetic dog your vet is likely to advise speying (neutering) her. This is because hormone changes during a season can make diabetes hard to control.

Will my dog get cataracts?

Cataracts are a very common complication of diabetes ( even if it’s very well managed). Cataracts aren’t painful, but cause vision loss and eventually blindness. Amazingly most dogs cope very well with going blind (especially if it’s gradual), but if your dog is struggling, it may be possible to have their cataracts removed at a specialist eye hospital.


Published: December 2020

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