Diabetes in Dogs: Symptoms and Treatments

There are so many parallels between human medicine and veterinary medicine. You might be surprised to learn that dogs can develop diabetes. If you already knew that, you might not know that veterinarians manage diabetes for their patients in the same ways that human endocrinologists do for theirs!

There are two different kinds of diabetes, but for the purposes of this article, we will discuss “sugar diabetes” known asdiabetes mellitus. The other kind,diabetes insipidus, is a rare disorder where a dog’s urine is extremely dilute due to low levels of anti-diuretic hormone (ADH), and the affected dog is constantly thirsty.

Diabetes mellitus is an endocrine disorder and is much more common than diabetes insipidus. It is caused by the inability of the pancreas to produce sufficient amounts ofinsulin, a hormone that tells cells to take inglucose (aka blood sugar).

There are also other instances where the pancreas produces sufficient amounts of insulin but the body becomes resistant to it. This type oftransient diabetes can occur due to the influence of other hormones like those present during pregnancy or estrus.

Cells use glucose for energy, and without insulin, cells cannot take up glucose. Instead, glucose sits in the bloodstream in large amounts. It is eventually excreted through the urine when the kidneys become overwhelmed. In healthy pets, the kidneys filter out glucose so that it goes back into the body instead of the urine. When cells do not receive enough insulin, it can lead to starvation and eventually organ failure.

Besides having elevated blood sugar (hyperglycemia) and sugar in the urine (glucosuria), there are common clinical signs associated with diabetes mellitus.

Increased urination and urinary accidents are common. When the kidneys need to excrete the excess sugar in the blood, it puts a demand on the kidneys for more water. This is because glucose has a high affinity for water, and so the volume of your dog’s urine will greatly increase. This will also cause dehydration and the need for even more water, so you will also notice an increase in his thirst as well.

When the cells in the body are not taking in enough glucose for energy, the body goes into starvation mode. Signals are sent out from the cells that more glucose is needed for their various jobs, and so your dog’s appetite will greatly increase. But because of this starvation mode, you might also notice that your dog is losing weight. This is because the starvation mode eventually leads to the break down of fat and muscle for energy purposes.

Poorly controlled diabetic patients are at risk for a serious condition known asdiabetic ketoacidosis. Infections and other illnesses can cause symptoms like vomiting, diarrhea, and lethargy. Dogs with these and other signs may stop eating and drinking, and this results in the liver break down fat into acids known asketones. When a lack of appetite and thirst goes on for a couple of days or longer, the risk of DKA increases, and your pet will require immediate hospitalization for this critical crisis.

Dogs with diabetes are also at a greater risk of developingpancreatitis. This is when the pancreas becomes inflamed and causes severe upper abdominal pain, vomiting, and lethargy. Dogs with diabetes may also developcataracts in their eyes. This is when the lens (the clear part inside of the eye that focuses light) becomes white and cloudy due to excess blood sugar. It can greatly affect your dog’s vision.

Patients who are in a diabetic ketoacidotic crisis require aggressive therapy and hospitalization for a few days. Once a patient is more stable, the veterinarian will then start them on injectable insulin. Prescription diets are available that are low in carbohydrates, but ultimately, the type of diet will not impact a dog so much as his overall body condition score. It is important to feed canine diabetic patients twice a day, and consistency is key. This means that if your dog has diabetes, he should be fed the same amount at the same timeevery time.

Your dog should be given his insulin injection about fifteen minutes after he eats. If he only eats half of his food, then he should receive half of the normal amount of insulin. If he isn’t eating at all, he should not receive insulin. If inappetence persists for more than 24 hours, call your vet right away.

Glucose monitoring is an important part of diabetes management. Your vet might give you a glucometer so that you can spot-check your dog’s glucose. Keep in mind that high numbers are concerning but should only be interpreted in a glucose curve which involves taking multiple readings one to two hours apart. Numbers can fluctuate, so the occasional high number should not cause worry. Very low numbers (less than 100) are more concerning becausehypoglycemia can cause seizures, and you should always contact your vet if the number is low.

If your dog does not like his glucometer, or if you are having trouble checking his sugar at home, more veterinarians are becoming familiar with continuous monitoring devices like the FreeStyle Libre. This is a small disc-like device that humans use to continuously monitor their sugar levels. It stays on their skin for up to 14 days and can be scanned with a reader or a convenient application on their cellular phone. Several studies have been published that proves their efficacy in dogs and cats, and there is mention of these devices in the most recent diabetes management guidelines from the ACVIM.  

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Unfortunately, there is no cure for diabetes in dogs. But once your dog’s diabetes is well-controlled, he can go back to having an excellent quality of life, and many dogs with diabetes live for a few years after their diagnosis. In the initial stages, treatment for diabetes can be expensive as your vet works to get your dog’s sugar levels under control. But once control is achieved, the cost of insulin, syringes, and diet becomes much more manageable.

If your dog has recently been diagnosed, the amount of information provided to you can seem daunting! Always ask your veterinarian for clarification on things you don’t understand, and ask for any resources that they can recommend to help you manage your dog’s diabetes. The American Animal Hospital Association (AAHA) has a great website with loads of information and how-to videos for insulin administration and glucometer checks.