Preventing and Treating Canine Diabetes

An all-too-common malady demystified
By Shauna S. Roberts PhD, November 2009, Updated August 2021
diabetes in dogs

Diabetes—when your body struggles to convert food into energy—isn’t limited to people. It can happen to dogs, too. Indeed, researchers estimate that one in 200 dogs will develop diabetes. 

The good news is, diabetes in dogs can be successfully treated. Recent advances in medicine have made it possible for diabetic dogs to live a long, healthy life (phew!).

So, if your pup was recently diagnosed with the disease, don’t panic. Check out the helpful guide below to learn: the types of diabetes in dogs, risk factors, symptoms, treatments, and more.

What is diabetes, exactly?

Just as cars use gas for fuel, body cells run on a sugar called glucose. The body obtains glucose by breaking down carbohydrates in the diet. Cells then extract glucose from the blood with the help of insulin, a hormone made by the pancreas in specialized cells called beta cells. (The pancreas, an organ situated behind the stomach, produces several hormones.)

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In diabetes mellitus, cells don’t take in enough glucose, which then builds up in the blood. As a result, cells starve and organs bathed in sugary blood are damaged. Diabetes in dogs is not curable, but it is treatable; a dog with diabetes may live many happy years after diagnosis.

Types of Diabetes in Dogs

You may have heard that dogs generally get Type 1 diabetes, but the reality is more complicated. Though there are no universally accepted definitions of dog diabetes, the United Kingdom’s Royal Veterinary College identifies two forms: insulin-deficiency diabetes (IDD) and insulin-resistance diabetes (IRD). 

In insulin-deficiency canine diabetes, a dog loses beta cells and no longer makes enough insulin to keep glucose levels under control. Causes include genetic defects, inflammation of the pancreas, and immune attack (like with type 1 diabetes in humans). 

In insulin-resistance canine diabetes, something prevents the dog’s insulin from functioning properly. That “something” may be “diestrus,” pregnancy, an endocrine disease, or treatment with steroids or progesterone-like hormones. Diestrus, the most common cause of IRD, is the approximately two months of high levels of progesterone (a female hormone) between periods of estrus (heat). Hormonally, diestrus resembles pregnancy, making this form of IRD similar to human gestational diabetes.

Risk Factors For Diabetes In Dogs

Several factors raise a dog’s risk of developing diabetes, including:

Breed. Mixed-breed dogs were more prone to diabetes than purebreds. Among purebreds, breeds varied greatly in their susceptibility. Dog breeds more prone to diabetes (from highest to lower risk) include Australian Terrier, Standard Schnauzer, Samoyed, Miniature Schnauzer, Fox Terrier, Keeshond, Bichon Frise, Finnish, Spitz, Cairn Terrier, Miniature Poodle, Siberian Husky and Toy Poodle.

Age. Dogs most often develop diabetes during middle or old age.

Gender. Female dogs and neutered male dogs are more likely than intact males to get diabetes.

Weight. Obesity can make cells resistant to insulin, but it’s unclear whether it actually causes diabetes in dogs.
Diet. A diet high in fat may contribute to pancreatitis (inflamed pancreas), which is a risk factor for diabetes.

Symptoms And Diagnosis of Diabetes In Dogs

Diabetes in dogs can be a silent disease. Your vet may discover your dog’s diabetes through routine bloodwork, but before that, you are likely to notice some diabetes symptoms: greater than normal hunger and/or thirst, weight loss, and frequent or copious urination (some dogs start having accidents in the house).

A blood test that measures your dog’s blood glucose level is the most common diagnostic tool, but a high glucose level does not always mean diabetes. Because other diseases sometimes raise these levels, your vet may run additional tests to rule out such causes.

Once your dog is diagnosed with diabetes, their veterinarian will obtain a “serial blood glucose–concentration curve” by measuring their glucose level repeatedly over many hours. The results will help the vet choose an appropriate insulin, dose, and dosing schedule. After treatment starts, your dog will need to be routinely tested to see how well the protocol is working. Most commonly, either a fructosamine test or a glycated hemoglobin test, which reveal average control over the previous one to three weeks (fructosamine) or two to four months (glycated hemoglobin) is used. In contrast, the daily blood glucose measurement is a snapshot, an indication of your dog’s glucose level at one specific moment

Treatment For Dogs With Diabetes

Treating diabetes is as much an art as a science. The goal of treatment is to keep blood glucose levels close to normal—roughly between 65 and 120 mg/dl—so that your dog feels good now and is less likely to develop diabetes-related problems later. 

The most common diabetic complication in dogs is cataracts (clouding of the lens of the eye); over time, dogs may also develop hardening of the arteries, kidney disease, retina disease or nerve disease. And because bacteria thrive on a high-sugar diet, dogs with diabetes are prone to gum, urinary, skin and other infections. Other components of treatment include proper diet, weight loss (if your dog is overweight), an exercise program and home testing of blood glucose levels.

Insulin. With rare exceptions, dogs with diabetes need one to two daily insulin shots to survive; the insulin is injected just under the skin. Your vet may prescribe a human insulin, or possibly Vetsulin, which is a purified pig insulin. Insulins vary greatly in how quickly they start working, when their action peaks, how long they last and how much they cost. Your vet will take these factors into account when choosing the best type for your dog.

Home monitoring. Weigh your diabetic dog regularly and watch for signs of excess hunger, thirst, and urination, which are indicators that their glucose levels may be too high. Regular testing of your dog’s blood glucose level can reveal problems before they become emergencies. 

Glucose levels rise after meals, occasionally when your dog is sick, and when the insulin dose is too low or timed improperly; they drop during fasting, after exercise, and when the insulin dose is too high or timed improperly. Both too-high and too-low levels can be dangerous. When interpreting the results, consider when your dog last ate, how much exercise she has had recently, when she received an insulin dose, how large the dose was and any symptoms.

Testing involves pricking a hairless area with a lancet, collecting the blood drop that wells up and using a small device called a blood glucose meter to measure the concentration of glucose in the sample. Many dog owners use human blood glucose meters. However, these meters tend to read low for dogs. The AlphaTRAK meter is designed for dogs and cats and requires only a tiny blood sample.

Diet. Researchers are still exploring what diet is best for dogs with diabetes. Most veterinarians recommend a diet low in fat and high in fiber. Fiber slows the entrance of glucose into the blood and may satisfy your dog’s appetite sooner, so they eat less and lose weight. Your veterinarian may recommend a prescription dog food designed for dogs with diabetes, or a homemade diet developed by a veterinary nutritionist. Some dogs may refuse to eat special diets; in that case, careful choices should be made when selecting a regular dog food. 

Exercise. Exercise not only may help reduce your dog’s weight, it also lowers blood glucose levels. Your dog should exercise every day for about the same length of time at about the same exertion level. Consistency is important—an unusually long or vigorous exercise session can cause blood glucose levels to drop dangerously low.

Weight loss. If a dog is overweight, shedding some pounds can make the cells more sensitive to insulin, which means that glucose uptake is easier.
Spaying. Spaying prevents female dogs from going through diestrus.

Living with a Diabetic Dog

It’s a good idea to keep a logbook to help you monitor your dog’s progress. Every day, record blood glucose test results; any ketone test results; changes in your dog’s appetite, weight, appearance, water intake, urination frequency or mood; and any treatment changes your veterinarian makes. A simple notebook or notes app on your phone works well. 

On a day-to-day basis, you want to watch out for the following in your dog: 

Hyperglycemia: This is when blood glucose levels rise above the top end of the recommended normal level (ask your vet what this is for your dog; since perfect control isn’t always attainable with current methods, vets generally try to keep most dogs below 200 mg/dl). Hyperglycemia can lead to ketoacidosis (harmful levels of ketones in the blood), which qualifies as an emergency, and you should call your vet right away. Symptoms include drinking lots of water, urinating frequently or copiously, loss of appetite, weakness, vomiting, lethargy, ketones in the urine, or—in the most serious situation—coma. Test strips are available to detect ketones in your dog’s urine, and you should report the presence of ketones to your veterinarian immediately, even if your dog has no other symptoms.

Hypoglycemia: You’ll notice a range of symptoms, including restlessness, lethargy, confusion, weakness, wobbliness, lack of coordination, shivering, sweaty paws, seizures or coma. Test your dog’s blood glucose level if these symptoms appear. If it is below the recommended level, rub maple syrup, Karo syrup or tube cake frosting—high-sugar foods that are quickly absorbed into the bloodstream—on your dog’s gums and the inside of their cheek, then call your vet to report the episode and get further instructions.

The Bottom Line: Diabetes in Dogs

Modern medicine has made taking care of a diabetic dog totally doable. It might feel overwhelming at first. But once you get used to it, it becomes a routine part of the day like taking your dog for a walk or feeding them (don’t worry: Shots and blood tests will not take over your life). A diabetic dog can live a long, happy life—and so will you with them by your side

Article first appeared in The Bark, Issue 41: Mar/Apr 2007

Shauna S. Roberts, PhD, is an award-winning science and medical writer and copyeditor who specializes in arthritis, diabetes and related subjects.