Diabetes in Dogs

LAST UPDATED 23rd November 2022

This article is written by Pet Circle veterinarian, Dr Nicole du Plessis BVSc (Hons)

Did I hear that right? Dogs can develop diabetes too? Diabetes is a condition that can affect dogs of all breeds, shapes and sizes. So, what does this mean for your dog? Apart from laying off the doggy snacks...


What is diabetes in dogs?

Types of diabetes in dogs?

Causes of diabetes in dogs?

Symptoms of diabetes in dogs?

How to diagnose diabetes in dogs?

Treatment of diabetes in dogs?

How to manage diabetes in dogs?

Complications of diabetes in dogs?

Further reading

What is diabetes in dogs?

The pancreas is an important organ, with both hormone and digestive functions. It is made up of different populations of cells. Diabetes affects the beta islet cells of the pancreas, which are responsible for producing the hormone insulin.

When your dog eats a meal, the food is broken down to fatty acids, amino acids and sugars (one being glucose) to facilitate absorption into the bloodstream via the small intestine. Insulin is essential to help cells in the body utilise glucose for energy. When there is reduced or no insulin being produced, the cells become starved of energy and glucose levels rise in the bloodstream. This is called hyperglycaemia. The typical signs associated with diabetes are caused by hyperglycaemia.

DID YOU KNOW? In one study, Diabetes Mellitus is 3 times more likely to affect females than males. It is usually diagnosed between 4 and 14 years of age.3 Most common onset is in middle aged dogs between 7 and 9 years of age.2

Causes of diabetes in dogs?

There are many different causes that could result in a dog acquiring diabetes in their lifetime. As with many diseases, there are several external and inherent risk factors that can also influence whether a dog will develop diabetes.


The genetic determinants of dogs with diabetes are not fully understood. Similar to other health conditions, certain breeds seem to have a genetic predisposition for diabetes. This will vary depending on the geographic location (genetic influence) and other risk factors present in the dog.

DID YOU KNOW? The prevalence of diabetes mellitus in Australian dogs is thought to be 0.36%.1 That is 1 in every 360 dogs. This number may be lower as many factors can influence disease prevalence, such as breed popularity and number of dogs attending veterinary clinics.

Breeds predisposed to diabetes:

Many popular breeds have a genetic predisposition for developing diabetes. Amongst these are the Bichon Frise, Cairn terrier, Keeshond, Miniature wirehaired dachshund, Norwegian elkhound, Spitz, Tibetan terrier and Yorkshire terrier.

Immune-mediated disease

This is the most common cause of diabetes in dogs. The immune system attacks the insulin-secreting cells of the pancreas, resulting in reduced insulin production, which is needed to regulate blood sugar levels. These dogs will require lifelong treatment with insulin, hence the term insulin-dependent diabetes (also referred to as type I diabetes).


Pancreatitis is a serious and often painful condition that occurs fairly commonly in dogs. The pancreas can become inflamed for a variety of reasons and pancreatitis can be acute or chronic. As well as its hormonal functions, the pancreas also secretes enzymes into the small intestine to help facilitate digestion of nutrients. In pancreatitis, these digestive enzymes are released and activated prematurely, resulting in damage and inflammation to the pancreas itself.

If enough damage has occurred to the pancreas, particularly if the dog has had many multiple or severe episodes of pancreatitis, then there can be a lack of functional cells remaining to produce and release insulin. This can then lead to diabetes mellitus. Up to 30% of dogs diagnosed with diabetes had evidence of destruction of the insulin-secreting cells due to pancreatitis.4.


In dogs, obesity may be a predisposing factor for developing diabetes, however it is not thought to be a direct cause. Overweight dogs are at an increased risk of developing pancreatitis and are often being fed a high fat diet and treats. Obesity can also reduce the effects of insulin, which can make management of diabetes challenging.

Other causes

Certain hormones can interfere with the effects of insulin. Pregnant dogs, or entire dogs during dioestrus, produce progesterone, which can reduce the effects insulin. Hyperadrenocorticism or 'Cushing's disease' is a common endocrine disease in dogs. It causes an overproduction of cortisol, which can also can reduce the effects of insulin and may predispose them to developing diabetes. One study found that 23% of dogs with diabetes mellitus had hyperadrenocorticism concurrently. 5 While uncommon, infection of the pancreas can also result in loss of the functional pancreatic cells, leading to reduced or no insulin being produced.

Symptoms of diabetes in dogs?

High blood sugar, also known as hyperglycaemia, can cause many symptoms in dogs. It is always a good idea to keep an eye out for anything out of the ordinary for your dog.

The most common symptoms of dogs with diabetes mellitus are:

  • Drinking lots of water
  • Urinating frequently and/or larger volumes
  • Always hungry
  • Weight loss
  • Less active or sleeping more often
  • Dehydration
  • Cloudy eyes

If diabetes is left untreated or poorly regulated, it can lead to life-threatening complications and can be fatal.

How to diagnose diabetes in dogs?

To diagnose diabetes in dogs, your veterinarian will need to get a thorough history of your dog's symptoms. To definitively diagnose diabetes, there must be persistently high glucose in the urine and in the blood.

This is found by doing a simple blood test and urine test. As dogs are usually middle-aged to older, additional blood and urine tests are often used to rule out other medical conditions and infections. In borderline cases, repeat testing may need to be performed.

Treatment of diabetes in dogs?

Diabetes cannot be cured, however it can be managed with medication and regular monitoring. The aim of treating diabetic dogs is to regulate blood sugar and reducing the clinical signs (increased thirst and urination, weight loss and hunger). Preventing hypoglycaemic (low) or hyperglycaemic (high) events through medication reduces the symptoms seen with diabetic dogs.

Treating diabetes in dogs involves administering insulin, usually twice daily. Insulin cannot be given orally, it must be given by an injection under the skin. This means owners will need to be comfortable giving an injection at home. Your veterinarian or veterinary nurse will be able to educate you on how to perform this on your own. Different types of insulin will use U-100 syringes or U-40 syringes. Using the wrong syringe can result in an incorrect dosage of insulin given to your dog. This can lead to poor control of blood sugar levels, staying too high (hyperglycaemia) or low (hypoglycaemia).

Hypoglycaemic event in dogs is blood glucose 3.3mmol/L or lower. However, symptoms of low blood sugar in dogs may not be seen until blood glucose has dropped between 2.2mmol/L and 2.8mmol/L.7

Symptoms of low blood sugar in dogs:

  • Weakness, difficulty standing
  • Collapse
  • Changes in behaviour
  • Lethargic
  • Muscle tremors
  • Seizures
  • Coma and sometimes death

If you suspect an overdose of insulin has been given or your dog is suffering from a hypoglycaemic event, contact your veterinarian immediately. In some cases, your vet may recommend a sugar syrup to be rubbed on the gums prior to presenting to the vet clinic. Never use substitutes that contain artificial sweeteners such as xylitol.

How to manage diabetes in dogs?

Diabetes requires life-long monitoring of the dog's symptoms, blood glucose and screening for concurrent issues that can arise in diabetic dogs. It is a big commitment, but many diabetic dogs can go on to live happy lives.

DID YOU KNOW? Technology can help improve the lives of diabetic dogs too! Continuous blood glucose monitoring (CGM) are wearable devices that allow blood glucose to be measured over several days, providing valuable readings. Although there are no registered CGMs for veterinary patients, they do eliminate the need for multiple blood draws over the day. Not to forget the apps for your phone, which make tracking your pet's blood glucose much more simple: Pet diabetes tracker app.

Even after long stretches of blood glucose levels being stable, there are many factors that can disrupt this:

  • Stress
  • Weight fluctuations
  • Other diseases or infections
  • Exercise increases or decreases
  • Medications
  • Hormones

Feeding a diabetic dog

Nutrition is an important aspect for the management of diabetic dogs. The composition and timing of the meals can have an effect on blood glucose throughout the day. As many of the symptoms of diabetes is related to blood sugar, food becomes an integral part of managing a diabetic dog.

Some tips for feeding a diabetic dog are:

  • Feed your dog at the same time each day, coinciding with insulin
  • Avoid changing the diet
  • Feed dry food diets that contain good quality protein, high in fibre and complex carbohydrates and moderate to low fat.

Your treating veterinarian will be able to make a diet recommendation that will best suit your diabetic dog. As some dogs are overweight at the time of diagnosis, your vet may also discuss a weight-loss plan to help with the long-term management of diabetes. There are many prescription diets that are designed to help aid in the management diabetic dogs. Please note not all prescription diets are suitable for all diabetic dogs, for example, those who are underweight or those with concurrent pancreatitis.


Exercise is essential for keeping dogs happy and healthy. Similarly to diet, there are certain considerations when exercising a diabetic dog.

Tips to exercise diabetic dogs:

  • Strenuous exercise should be avoided unless otherwise directed. Running, hiking or agility will use lots of energy and can cause blood sugar to drop lower than expected. Always speak to your veterinarian if planning such activities.
  • Weight-loss is important for overweight dogs, as it can reduce insulin resistance associated with obesity. It will also help ward off many other obesity-related health problems. Steady weight loss is ideal until reaching 'ideal weight,' as medication may need to be adjusted by your veterinarian.


If your entire female dog has been diagnosed with diabetes, your veterinarian will recommend desexing. This is because of the hormonal influence on the effects of insulin.

Complications of diabetes in dogs?

Most dogs with diabetes can go on to live happy lives, with regular monitoring, optimal nutrition, lifestyle changes and regular veterinary check-ups.

However, serious complications can arise from the diabetes left untreated or from factors affecting the efficacy of treatment.

Complications of diabetes in dogs:

  • Seizures: if blood sugar drops too low, known as hypoglycaemia, this can cause seizures. This can be a life-threatening complication of poorly controlled diabetes mellitus or an overdose with insulin.
  • Diabetic ketoacidosis: as diabetes interferes with the glucose being used by cells in the body, they become starved of energy. This causes fat stores to be broken down for energy, producing ketones. This becomes overwhelming for the body and causes acidosis and severe electrolyte imbalances. This is a serious and life-threatening condition. Without aggressive medical treatment, it is fatal.
  • Cataracts: the lens is a structure that helps focus images onto the retina in the back of the eye. In diabetic dogs, too much glucose causes the lens to become cloudy. This affects the dog's vision and can eventually result in blindness. Unfortunately, diabetic cataracts can occur incredibly quickly. It is not always an indication of poorly controlled diabetes.
  • Diabetic neuropathy: fairly uncommon complication in dogs with diabetes, but can be seen in cats. This can result in nerve dysfunction from prolonged high blood sugar levels.
  • Hyperglycaemic Hyperosmolar Syndrome (HHS): can occur with severe hyperglycaemia, usually over 33.3mmol/l. It will cause severe dehydration and is a life-threatening condition. It requires aggressive medical treatment to try and correct.

DID YOU KNOW? Cataracts are an extremely common complication of diabetes mellitus in dogs. Approximately 75% of dogs will develop cataracts and experience a degree of vision loss nine months after diagnosis. 6 To learn more ways you can support your dog, see our article Sensory loss in dogs.

Further Reading

Want to read more? Check out our other articles:

Causes of vomiting in dogs.

Obesity in dogs and cats.

3 daily habits to improve your pet's health.

Pregnant dog guide.

5 ways to help ease your dog's arthritis.


This article was written with contributions from Dr. Sophia Wyatt BVSc (hons I) MANZCVS Small Animal Medicine.

  1. Yoon S, Fleeman LM, Wilson BJ, Mansfield CS, McGreevy P. Epidemiological study of dogs with diabetes mellitus attending primary care veterinary clinics in Australia. Vet Rec [Internet] 2020. Cited 18 November 2022
  2. Bruyette D: Treatment Canine Diabetes Mellitus: What Are My Options. Western Veterinary Conference 2010. Cited 18 November 2022
  3. Merck Animal Health: Vetsulin What is canine diabetes mellitus? Cited on 28th October, 2022.
  4. Fleeman LM: Sweet Success: Nutritional Management Of The Canine Diabetic. ACVIM 2010. Cited on 1st November 2022.
  5. Hess RS, Saunders HM, Van Winkle TJ et al: Concurrent disorders in dogs with diabetes mellitus: 221 cases (1993-1998). J Am Vet Med Assoc 2000 Vol 217 (8) pp. 1166-73. Cited on 9th November, 2022.
  6. MaCalla T: Cataracts, Blindness and Diabetic Dogs. Animal Eye Care, 2020. Cited on 9th November, 2022.
  7. Olutunbi I, Heading K. Hypoglycemia in dogs: Causes, management, and diagnosis. Can Vet J. 2018 Jun; 59(6): 642–649. Cited on 23rd November

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