Diabetes in Dogs: Causes, Signs, and Treatment

Diabetes in dogs is a serious but manageable condition that affects how your dog’s body uses glucose for energy. Canine diabetes requires lifelong care, including, insulin therapy, diet changes, and regular vet checkups.

It may sound overwhelming at first, but with the right care and support, you can help your diabetic dog live a full and happy life.

What Is Diabetes in Dogs?

Diabetes in dogs is a common disorder characterized by elevated levels of blood glucose (blood sugar) that affects how the body turns food into energy. 

Insulin is a hormone produced by the pancreas that regulates the amount of blood sugar in the blood. Lack of insulin production causes diabetes and prevents blood sugar from getting into the cells of the body and becoming energy. Over time, elevated blood sugar levels can cause serious health problems.

Undiagnosed or diagnosed diabetes in dogs can turn into a medical emergency called diabetic ketoacidosis (DKA).

If your pet is vomiting, having diarrhea, has a decreased appetite, or is lethargic, call your vet to discuss if your dog needs to be seen immediately.

Types of Diabetes in Dogs

There are primarily two types of diabetes in dogs:

• Type I: Known as insulin-dependent diabetes and is like Type I diabetes in humans. This is the most common type to occur in dogs.

  • In Type I diabetes, insulin-secreting cells in the pancreas are destroyed, causing an absolute lack of insulin. This damage to the pancreatic cells can occur due to autoimmune attacks to the pancreas or severe recurrent pancreatitis. These dogs will require lifetime insulin supplementation therapy made specifically for dogs, like Vetsulin. 

• Type II: Known as non-insulin-dependent diabetes and is like Type II diabetes in humans. This form of diabetes is typically related to obesity but is very rare in dogs.

  • In Type II diabetes, the pancreas may produce less insulin, and the body’s cells respond poorly to the insulin that is secreted. This leads to less glucose entering the cells (and higher glucose in the blood).

Symptoms of Diabetes in Dogs

Symptoms of diabetes in dogs include:

• Increased thirst
• Increased urination
• Increased appetite
• Weight loss
• Lethargy
• Dehydration
• Cataracts

Long-term effects of diabetes in dogs, if unregulated or untreated, are severe and eventually fatal. Some common secondary and long-term effects include the following:

• Seizures: Low blood sugar can lead to hypoglycemic seizures.
• Liver disease: Fatty liver can occur secondary to diabetes resulting in elevated liver values.
• Diabetic ketoacidosis (DKA): DKA is a life-threatening complication of diabetes. It occurs when a diabetic dog develops a secondary medical condition that places additional stress on the body (e.g., pancreatitis or urinary tract infection). This causes the body to break down fat for energy and create ketones that acidify the blood.
• Hyperglycemic hyperosmolar syndrome (HHS): HHS is a life-threatening complication of diabetes that occurs when the blood sugar is too high for too long, leading to severe dehydration and disorientation.
• Diabetic neuropathy: Neurologic damage that can lead to paralysis in rare cases.  

Causes of Diabetes in Dogs

Diabetes in dogs can have several causes. Most dogs acquire Type I, or insulin-dependent diabetes. Type I diabetes is most likely due to the immune system mistakenly attacking insulin-producing cells in the pancreas, leading to a total—or partial—loss of insulin secretion.

Other risks and complicating factors of diabetes include:

• Genetics
• Increased hormone levels (progesterone, growth hormone, and cortisol)
• Cushing’s disease
• Chronic pancreatitis
• Obesity and high-fat diets

Females and middle-aged to senior dogs have a higher risk of diabetes, as well as dogs that are obese. Dog breeds that are predisposed to diabetes include:

• Alaskan Malamute
• Australian Terrier
• Bichon Frise
• Cairn Terrier
• Keeshond
• Labrador Retriever
• Miniature Schnauzer
• Miniature Dachshund
• Norwegian Elkhound
• Poodle
• Pug
• Samoyed
• Siberian Husky
• Tibetan Terrier
• Yorkshire Terrier

How Veterinarians Diagnose Diabetes in Dogs

Veterinarians may suspect diabetes in dogs based on physical exam findings and symptoms shown at home. However, to officially diagnose diabetes, veterinarians must find persistent high blood and urine glucose values.

Your pup may also have the following tests:

• Blood chemistry and complete blood count (CBC)
• Urinalysis
• Fructosamine
• Radiography
• Thyroid tests
• Cushing’s testing
• Abdominal ultrasonography
• Pancreatitis blood testing

Treatment of Diabetes in Dogs

For uncomplicated cases, treating diabetes in dogs primarily includes insulin and diet changes.

Insulin

Insulin is the main treatment in dogs with diabetes. Insulin for pets is different than the insulin used for humans:

• Pet insulin comes from the pancreas of pigs (porcine-based insulin) or cows (bovine-based insulin). Since dog and pork insulin are essentially the same molecule, porcine-based insulins like Vetsulin are typically recommended for use in diabetic dogs.

• Pet insulin comes in different concentrations than human insulin. Where biosynthetic human insulin is only available in 100 IU/mL concentrations, pet insulin comes in 40 IU/mL concentrations, which allows for more accurate dosing of small animals and reduces the risk of under- or overdosing. (Though depending on the specific needs of the pet and case, vets often do prescribe human insulins off label for pets, therefore utilizing the 100 IU/mL strength but at a lower dose.)

All insulin for dogs is absorbed subcutaneously, which requires an injection under the skin. Most dogs require insulin injections twice daily. The amount of insulin for dogs is typically not large, and the needles are tiny.

It’s important to use the correct syringe for the prescribed insulin concentration. Insulin for dogs with a 100 IU/mL concentration should be used with U-100 syringes and insulin for dogs with a 40 IU/mL concentration should be used with a U-40 syringe. 

Most dogs tolerate insulin injections very well. However, the injection must not be given in the same location every day or scar tissue may form. If this occurs, the insulin won’t be absorbed properly.

Diet

Diet therapy is important when treating diabetes in dogs. Pet parents should feed their dogs the same thing, around the same time every day. Consistency is key and leads to better and faster regulation of blood sugar in dogs.

Veterinary diets are available for diabetic dogs. These diets, available only with authorization from your veterinarian, typically contain high fiber with appropriate fat, protein, and carbohydrate ratios that help maintain blood-sugar levels. Some commonly recommended foods for diabetic dogs include Royal Canine Veterinary Diet Adult Glycobalance Dry Dog Food and Hill’s Prescription Diet w/d Multi-Benefit Dry Dog Food.

Speak with your vet about what diet is best for your pup and their individual needs.

Recovery and Management of Diabetes in Dogs

Dogs with diabetes require lifelong monitoring and treatment. Insulin and diet control are typically needed for life. Download this tracker to keep a record of your dog’s daily treatment.

Initially after diagnosis, your dog may need frequent vet visits to help your vet determine the best insulin dose for treatment to control your pet’s blood sugar. 

After that, if your pet is well regulated, vet visits may be every three to six months and will likely include some blood tests to ensure their diabetes is well controlled.

There are four main ways to monitor a dog’s response to insulin treatment:

• Blood glucose curve is usually the most accurate way to monitor your dog’s blood sugar. Your dog will stay at the veterinary hospital for the day, having blood drawn every one to two hours. These values are plotted on a chart, which typically looks like a curve. Based on the shape of the curve, the highest blood glucose and the lowest blood glucose, your veterinarian will determine if a change in dosage is necessary.
• Freestyle Libre involves the placement of a small sensor on your dog’s skin to measure blood glucose. Glucose can be checked frequently—without drawing blood—on a device reader or smartphone app. This is especially useful for dogs who tend to be anxious or uncooperative.
• Fructosamine can be used to provide a general idea of how well glucose is being regulated over the previous two to three weeks. This may be used as a chronic monitoring tool. 
• Urine glucose and ketone measurements are an easy and inexpensive way to monitor dogs at home. This test comes as a small strip that is placed in the stream of urine. The results can be used to help your veterinarian determine if your pet is well regulated.

While the cost of insulin may only be $30 to $150 per month, the cost to care for a diabetic patient considering all blood work and therapies may be upward of $2,500 per year. Pet insurance may be a good way to help offset these costs. 

Management goals for pups include reducing symptoms, maintaining a healthy blood-glucose level, and improving quality of life.

Therapeutic goals for diabetes in dogs are different from those in humans. Veterinarians do not control animals’ glucose as tightly as humans. This means that goal blood glucose readings for dogs may be much higher than expected if a pet parent is familiar with diabetic regulation in humans.

The prognosis for diabetic dogs is based on multiple factors. Uncomplicated diabetics is typically regulated easier and requires only a few visits to the vet per year for monitoring.

Complicated cases of diabetes can be difficult and frustrating for pet parents and veterinarians to manage. If your vet is concerned your pet has complicating factors, they may enlist the help of a veterinary specialist called an internal medicine specialist.

Never adjust your pet’s insulin without the direction and supervision of your veterinarian. 

If your dog is not eating or they’re vomiting, call your vet to determine if you should give their insulin. If they are experiencing any signs of low blood sugar, such as weakness, “star-gazing,” or tremors/seizures, they should be seen by their vet or an emergency vet immediately.

If your dog is showing a breakthrough of clinical signs, such as increased drinking, tell your vet. They may want to check their blood work to determine if your dog’s diabetes is well controlled.

Prevention of Diabetes in Dogs

While diabetes in dogs is not preventable, there are some things pet parents can do to help.

All dogs should be seen by their vet every year for a wellness exam and blood work.

Senior dogs, typically over the age of 7, should be taken to the vet every six months. This exam and blood work can detect changes well before they show up as clinical signs. Therefore, dogs can receive treatment or have lifestyle changes before they are sick, leading to a better quality of life and a longer lifespan.

Pet parents should also provide a high-quality diet and regular exercise to help dogs stay lean and active.