Diabetes Mellitus (Diabetes) in Dogs

Diabetes Mellitus (Diabetes) in Dogs

Animals Affected



Diabetes mellitus (known simply as diabetes) is a serious disease of dogs.  The main characteristic of diabetes is an inability to control the level of sugar in the blood.  This leads to chronically high blood sugar levels, which in turn lead to the symptoms of the disease.

Management of diabetes in dogs is challenging but possible.   With proper treatment, many diabetic dogs lead essentially normal lives.  However, without treatment the disease inevitably leads to serious complications.

Diabetes in dogs is similar to type 1 (juvenile onset) diabetes in humans.


Symptoms of diabetes include:

Risk Factors and Prevention

  • A genetic or hereditary predisposition to diabetes appears to be a primary risk factor.
  • Dogs that suffer from one or multiple bouts of pancreatitis may develop diabetes as a consequence of damage to the pancreas.  Dogs aged 4 – 14 years are at highest risk of pancreatitis.
  • Female dogs are diagnosed with diabetes more often than males.
  • Miniature Poodles, Miniature Schnauzers, Pugs, Samoyeds, and Toy Poodles suffer diabetes at higher rates than other breeds.
  • Overweight or obese dogs are predisposed to diabetes.
  • Prednisone and related medicines may predispose dogs to diabetes.
  • Syndromes such as Cushing’s disease and periodontal disease predispose dogs to diabetes.


  • Untreated diabetes leads to emaciation, chronic lethargy and weakness.
  • Diabetic dogs are prone to urinary tract infections.  House soiling may occur as well, due to increased frequency of urination.
  • Insulin administration is the main method of treating diabetes in dogs.  However, some dogs may suffer from accidental overdose.  This has the potential to be fatal. Click here for more information on the signs and prevention of insulin overdose.
  • Diabetes causes cataracts in a large proportion of canine patients.   In some dogs, cataracts develop literally overnight, causing the eyes to become white and cloudy. Most cataracts can be treated surgically.  Untreated cataracts cause blindness and may lead to severe inflammation of the eyes.
  • Diabetic dogs have weakened immune systems and are at increased susceptibility for all types of infections.
  • Untreated diabetes, over time, may lead to potentially fatal syndromes including diabetic ketoacidosis (DKA), and nonketotic hyperosmolar syndrome.  These syndromes require hospitalization and intensive care and monitoring.   Even with appropriate treatment, dogs suffering these syndromes may not survive. Therefore, preventing these syndromes is a core goal in management of canine diabetes.


In most cases, simple blood and urine tests provide a conclusive diagnosis by showing elevated levels of sugar in the blood and urine.  Ultrasound of the pancreas is recommended in many cases.


  • Insulin administration is the mainstay of managing diabetes in dogs. Generally, the owner of the dog administers the insulin.  After initiating insulin treatment, follow-up diagnostic testing and monitoring are necessary at regular intervals to ensure proper dosing.  It is critical to follow the recommendations of your veterinarian carefully at all times.

Administering insulin injections to dogs is daunting to most owners during the initial stages.  However, the vast majority of people who care for diabetic dogs are able to master the task within a few weeks.

  • Switching diets may help to regulate blood sugar levels and manage diabetes.   The most commonly used diets are low in carbohydrates and high in fiber.
  • Regular exercise helps to control blood sugar levels.  Exercise also helps dogs to maintain a proper weight, which has a positive impact on treating diabetes.
  • Proper management of concurrent diseases (such as periodontal disease or bladder infections) helps to stabilize and control diabetes.


Every individual has a unique response to insulin.  Intensive monitoring is necessary after treatment has begun.

The most common method of monitoring a dog’s response to insulin is to run a series of blood sugar measurements over several hours.  This battery of tests is known as a blood glucose curve, and it provides insight into the strength and duration of the insulin’s effect.

Most veterinarians hospitalize dogs for the duration of blood glucose curves.  However, some newer methods have the potential to permit home measurement of blood sugar by the owner.  In either case, the veterinarian will use the results to assess the efficacy of the insulin and, if necessary, change the dose.

Often, several cycles of insulin adjustments followed by blood glucose curves are necessary to achieve adequate control of the disease.

Once diabetes is adequately controlled, symptoms such as lethargy, poor coat quality, and changes in water consumption may decrease.  However, this is not always the case. As mentioned above, the core goal of diabetic management is to prevent the potentially fatal complications that occur when the disease progresses unchecked.  Therefore, even with successful treatment, some of the outward symptoms of the disease may persist.

Dogs with diabetes may experience changes in the intensity of their disease, resulting in changes in the need for insulin.  Because of this, periodic blood sugar curves must be run even in dogs with well-managed diabetes.

Some owners of diabetic dogs rely on home test kits for sugar in the urine as a method of monitoring treatment of diabetes.  These kits are convenient and they offer some degree of insight into how well the disease is controlled.  However, most experts agree that this method not as accurate or reliable as blood testing.

Special Issues Regarding Use of Insulin

Although insulin is instrumental in treating canine diabetes, it requires special handling and administration. There is a risk of overdose, which can be fatal. For detailed information on the prevention of insulin overdose in dogs, as well storage and handling of insulin, please click here.


Blood sugar measurements in dogs with diabetes may be much higher than those of humans afflicted with the disease.  In dogs, measurements higher than 600 mg/dL are not uncommon.

Canine diabetes is similar to type one (juvenile onset diabetes) in human beings. However, dogs very rarely develop diabetes as juveniles.

Forms of insulin that can be administered by methods other than injection may be available soon.  Alternative administration methods under development include inhalable insulin, and insulin administered by eye drops.  At this time injecting insulin is the gold standard of treatment.

Some experts advocate performing blood sugar measurements and full blood glucose curves at home using human instruments.  There are many benefits to this method.  Key among them is the elimination of the need to hospitalize the dog for the duration of the test.  Unfortunately, difficulties with calibration of human instruments and the reluctance of some owners to collect blood samples from their dogs have hindered the conversion to this method.

Copyright © Eric Barchas, DVM All rights reserved.
The contents of this page are provided for general informational purposes only. Under no circumstances should this page be substituted for professional consultation with a veterinarian.