Even dogs eating healthy diets can suffer from diabetes. As with diabetes in humans, sometimes a dog’s body’s stops producing enough insulin or the cells of a dog’s body are unable to use the insulin that is produced. When either condition occurs, the result is diabetes mellitus, which causes excessive thirst and urination and extreme hunger accompanied by weight loss. To stabilize sugar levels, insulin therapy is the treatment at the outset and is usually required for the life of the dog.


Diabetes mellitus is a disease that manifests as an inability of the animal’s body to use carbohydrates (sugars) properly. This occurs either because the pancreas does not manufacture sufficient quantities of the hormone the body requires for this function (insulin) or because the body’s cells no longer recognize insulin properly.

The downside of this fundamental aberration in carbohydrate utilization is that these basic, energy providing nutrients (sugars) are not able to enter the body’s cells to “feed” them. Instead, they linger in the bloodstream while the body itself literally starves.

By way of handling this starvation state, the body does things like start to break down certain tissues, fats for example, and mobilize stored sugar (glucose) in the body to attempt to generate energy with which to feed itself. In the absence of the insulin required to allow sugars to gain entry to the cells, these efforts typically lead to a dangerous metabolic state called ketosis. Moreover, when sensitive tissues like the brain don’t receive the required amount of energy, serious neurologic disruption — and death — can ensue.

Diabetes mellitus is considered a multifactorial disease in origin, meaning that a variety of factors play into its individual acquisition. In cats, obesity is considered a primary risk factor for diabetes. Certain drugs (such as corticosteroids) as well as a possible genetic predisposition (in Burmese cats) also contribute to developing the condition.

In dogs, a genetic predisposition to diabetes mellitus plays a larger role than obesity or exposure to certain drugs.

Symptoms and Identification

Excessive thirst and urination: This happens because the huge quantity of sugar in the bloodstream spills into the urine and pulls water out of the bloodstream along with it, thereby causing increased urine production and urination. Increased drinking is the body’s way of trying to compensate for increased water loss through urination. Due to the high levels of bacteria-attracting sugar in the urine, urinary tract infections are a routine finding, as well.

Appetite increase paired with weight loss: This happens because when sugars cannot enter cells, the body is unable to effectively use the food it takes in as energy. Hunger is never satisfied despite a typically ravenous appetite, and weight loss is almost always a feature.

Other symptoms may include:

  • Urinary accidents in the house
  • Vomiting
  • Dehydration
  • Lethargy (tiredness)
Veterinarians may suspect canine diabetes if any suspicious clinical signs, such as increased drinking and/or urinating, have been observed at home. After performing a thorough physical examination, your veterinarian may recommend some of these tests to help confirm a diagnosis:

CBC (complete blood count) and chemistry profile: When a pet is ill, these tests are commonly performed together during initial blood testing to provide information about the pet’s organ systems. The CBC and chemistry profile may show dehydration, an elevated blood sugar level, or other changes that can occur with diabetes.

Urinalysis: Evaluation of a urine sample may show the presence of sugar (glucose) in the urine if a dog has diabetes.

Fructosamine: Fructosamine is a protein in the blood that binds very securely to glucose. The fructosamine level is therefore a close estimation of the blood glucose level, but it is less likely to change due to stress and other factors that affect the blood glucose level. Additionally, the fructosamine level indicates where the blood sugar levels have been during the previous two to three weeks. In a dog with diabetes, the blood sugar levels are usually high for long periods of time, which would be reflected by an increased fructosamine level.

Affected Breeds

Predisposed breeds include the Miniature Schnauzer, Standard Schnauzer, Poodle, Australian Terrier, Spitz, Bichon Frise, Samoyed, and Keeshond. Dogs of any breed, however, may acquire diabetes.


In the long term, dogs with diabetes are often treated by insulin injection to help the body’s needy cells use sugar more efficiently. Dietary changes can also help, by tempering sudden spikes in blood sugar levels. Insulin injections, however, are generally started at the time of diagnosis and required long term to control the disease.

In the short term, some patients require hospitalization. Some may even need intensive care should their presentation be complicated by a variety of other problems secondary to the diabetes (this is a common scenario).

After treatment begins, periodic blood and urine tests are generally recommended. This helps ensure that the insulin dosage is right for your dog. Your dog’s weight, appetite, drinking and urination, and attitude at home can all provide useful information that helps determine if his or her diabetes is being well managed. Your veterinarian will consider all of these factors when making recommendations for continued management.

Many dogs live active, happy lives once their diabetes is well regulated. However, insulin therapy and regular monitoring at home and by your veterinarian are necessary for the rest of your dog’s life.


Keeping your dog at a healthy weight can help reduce his risk of developing diabetes. However, for dogs that are genetically predisposed, their risk for developing disease remains higher even if they maintain a healthy weight.

This article has been reviewed by a Veterinarian.