Diabetes in Dogs and What You Need to KnowDiabetes mellitus is a disease caused by a lack of insulin in the body. A diagnosis of diabetes in dogs can be devastating and potentially life threatening.

With appropriate treatment and a dedicated owner, dogs can thrive even after a diagnosis of diabetes.

This article will explore everything you need to know about your dog’s diagnosis so you can ensure optimal treatment results.

Types of Diabetes in Dogs

There is more than one type of Diabetes Mellitus. Most dogs are diagnosed with Type I Diabetes, whereas most cats are diagnosed with Type II.

Type I Diabetes in dogs is similar Type I Diabetes in people. In people this usually happens in children, and lifestyle and weight doesn’t factor in as much.

Type I Diabetes is caused by destruction to the pancreas, resulting in an absolute insulin deficiency. These patients require lifelong insulin injections.

Type II Diabetes is thought to be most common in cats and is similar to Type II Diabetes in people. There is a relative lack of insulin production as well as insulin resistance, meaning the insulin present doesn’t work as well.

Diet, lifestyle and obesity play a role in the predisposition to and the treatment of Type II Diabetes. Most veterinary patients still require insulin injections.

There is a third type of Diabetes, Type III Diabetes.

Type III is caused by disease that creates insulin resistances in the body, for example Cushing’s disease which causes increased cortisol, which in turn makes insulin less effective. Treatment depends on the underlying disease.

In this article we’ll focus on the most common form in dogs, Type I Diabetes.

Diabetes Disease Process

Process of Diabetes in Dogs

Insulin is a hormone that allows glucose or sugar to be used by cells for energy. You can think of insulin as the bridge between the bloodstream and the body’s cells [1].

If there is no insulin, sugar circulates around the bloodstream and is eventually wasted in urine. Blood levels of sugar are high, called hyperglycemia, even though the cells are starving.

A deficiency in insulin seen in a diabetic animal results in a state of starvation. Sugar can’t reach the cells, so the body turns to burning fat stores for energy.

Utilizing only fat stores for energy can be sustained for a while, but eventually the ketone production secondary to fat breakdown makes patients very sick.

Common Clinical Signs of Diabetes

Excessive thirst and urination are classic hallmark clinical signs of diabetes in dogs.

Excessive glucose in the urine causes an osmotic pull of water, increasing urine volume, thus patients are urinating excessively. Since they are losing so much water in their urine, they will drink more, actually to keep up with what they are losing.

Weight loss occurs since cells can’t utilize glucose for energy and fat stores are burned instead.

Dehydration is not uncommon since patients lose the ability to conserve water by concentrating urine.

Weakness and lethargy can occur due to the state of hyperglycemia compounded with the state of starvation the body is in.

In the beginning of the disease process many dogs will act hungrier and eat more than normal. Often by the time they are diagnosed they are starting to feel poorly and may stop eating all together.

Most diabetic dogs will develop cataracts in the course of their disease. Most don’t initially present this way, but will eventually become blind due to cataract formation [2].

Diagnosis of Diabetes in Dogs

Diabetes in dogs is diagnosed with a blood test and urinalysis. Normal blood glucose is between 80 and 120. Dogs with diabetes are typically over 200, sometimes close to 500 to 600.

Normal urine should not have glucose in it. A urinalysis will confirm the presence of glucose in the urine in a diabetic patient. The combination of these two parameters, as well as the clinical signs listed above, will give your dog the diagnosis of Diabetes.

Why Dogs Develop Diabetes?

In dogs, Diabetes is thought to be an immune mediate disease process causing destruction of the cells in the pancreas responsible for the production of insulin [3].

Predisposing factors include genetics, breed predisposition, and chronic pancreatitis or inflammation of the pancreas due to other disease processes.

There is thought to be a genetic component to the development of Diabetes in the following breeds: German Shepherds, Schnauzers, Beagles, Poodles and Miniature Pinchers [4].

Female dogs are more than three times more likely than males to develop Diabetes. Most patients are middle age, six to nine years, when diagnosed [4].

Treatment and Management

Treatment of Canine Diabetes

Treatment of canine Type I Diabetes is a little different than in people with Type I Diabetes. In most cases it isn’t practical to test blood sugar regularly throughout the day.

This requires lancing or puncturing the skin to cause a small hemorrhage. Many dogs will not tolerate this.

In addition, dogs typically have one set ‘dose’ of intermediate acting insulin they receive twice daily, preferably after a meal.

People typically tailor their insulin dose based on when, what and how much they ate. Dogs generally don’t vary much in their day to day diet.

Lastly, people are expected to live hopefully 60 to 70 years. A child diagnosed with Type I Diabetes has much more potential for complications of poor diabetic control than a dog that has maybe 3 more years of normal life span.

Therefore, we don’t see the long term complications associated with slightly subpar glycemic control such as vascular problems and heart disease seen in people [5].

Veterinarians are more likely to see short term complications associated with too much insulin given, causing dangerously low blood sugar or hypoglycemia. Severe hypoglycemia can lead to seizures, coma and death.

Veterinarians tend to like their patient’s blood sugar to run just a little higher than normal, with the lowest point being between 100 and 200 [6]. This is safer and we don’t see the long term complications seen with mild persistent hyperglycemia in dogs [5].

After your dog is diagnosed with uncomplicated Diabetes, your veterinarian will calculate a slightly conservative dose of insulin based on your dog’s weight, which you will administer as an injection twice daily after a meal.

The dose may need to be increased based on your dog’s response to the dose.

More complicated cases, or really sick patients requiring hospitalization will require different treatment until they are stable, but then will start on the same treatment plan as an uncomplicated case when they are better.

Most veterinarians will want to see your dog back within a week to perform a glucose curve. This allows the veterinarian to see how blood sugar reacts over the course of the day [6].

Obviously blood sugar will be highest right before insulin is given, and typically lowest at midday.

Your veterinarian will want to monitor the trend over the course of the day to ensure the dose is correct. Once a correct dose is obtained, a test called a Fructosamine level can be used long term, which gives your veterinarian an idea of average glycemic control over the past 3 weeks [7].

Nutrition for Dogs with Diabetes

Food for Dogs with Diabetes

Nutrition guidelines for Type I Diabetic dogs indicate any well-balanced diet can be appropriate. It is important that the same amount is fed at close to the same time twice daily.

Ideally the meal is fed just prior to the injection, so when the insulin is working at it’s maximum, it coincides with when the gut is absorbing the most energy in the form of glucose.

Most veterinarians agree that treats, snacks and table scraps should be avoided.

There are prescription diabetic diets available that have been designed to minimize glucose spikes and help maintain an appropriate blood sugar [8].

Take Home Message

Managing canine Diabetes takes a dedicated owner.

Learning how the disease works will assist you in being best able to manage it.

It is possible to have a healthy diabetic dog that can live a fairly normal lifestyle [9].

[toggle title=”References“]
  1. Pfeifer MA, Halter JB, Porte D Jr. Insulin secretion in diabetes mellitus. Am J Med. 1981 Mar;70(3):579-88.
  2. Beam S1, Correa MT, Davidson MG. A retrospective-cohort study on the development of cataracts in dogs with diabetes mellitus: 200 cases. Vet Ophthalmol. 1999;2(3):169-172.
  3. American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2012 Jan;35 Suppl 1:S64-71. doi: 10.2337/dc12-s064.
  4. Fall T1, Hamlin HH, Hedhammar A, Kämpe O, Egenvall A. Diabetes mellitus in a population of 180,000 insured dogs: incidence, survival, and breed distribution. J Vet Intern Med. 2007 Nov-Dec;21(6):1209-16.
  5. Muñana KR. Long-term complications of diabetes mellitus, Part I: Retinopathy, nephropathy, neuropathy. Vet Clin North Am Small Anim Pract. 1995 May;25(3):715-30.
  6. Renee Rucinsky, Audrey Cook, Steve Haley, Richard Nelson, Debra L. Zoran, and Melanie Poundstone (2010). AAHA Diabetes Management Guidelines for Dogs and Cats. Journal of the American Animal Hospital Association: May/June 2010, Vol. 46, No. 3, pp. 215-224. doi: http://dx.doi.org/10.5326/0460215
  7. Greco DS. Diagnosis of diabetes mellitus in cats and dogs. Vet Clin North Am Small Anim Pract. 2001 Sep;31(5):845-53, v-vi.
  8. Kimmel SE1, Michel KE, Hess RS, Ward CR. Effects of insoluble and soluble dietary fiber on glycemic control in dogs with naturally occurring insulin-dependent diabetes mellitus. J Am Vet Med Assoc. 2000 Apr 1;216(7):1076-81.
  9. Aptekmann KP1, Armstrong J, Coradini M, Rand J. Owner experiences in treating dogs and cats diagnosed with diabetes mellitus in the United States. J Am Anim Hosp Assoc. 2014 Jul-Aug;50(4):247-53. doi: 10.5326/JAAHA-MS-6101.

Leave a Reply