Everything you need to know about diabetes in dogs

The two forms of diabetes in dogs, diabetes mellitus and diabetes insipidus, are very different conditions that affect different parts of the body. However, both conditions can lead to widespread health issues if left unmanaged. If you have a dog, keep reading to learn:

• What are the forms of diabetes in dogs?
• What are the common symptoms of canine diabetes?
• Is my dog at risk for diabetes?
• How is diabetes in dogs diagnosed and treated?

Diabetes mellitus, or sugar diabetes, is a common condition in dogs that leads to unregulated blood sugar levels. In addition to being unable to use glucose as an energy source for cellular metabolism throughout the body, dogs with diabetes mellitus are at risk for weight loss, recurring skin and urinary tract infections, and life-threatening diabetic ketoacidosis. Diabetes insipidus does not affect a dog’s blood glucose levels. Instead, urine production is uncontrolled, which can lead to severe dehydration. The two forms of diabetes have vastly different diagnostic processes and treatment options.

There are two different diseases called diabetes: diabetes mellitus and diabetes insipidus. These two conditions are distinct from each other despite sharing a name. Diabetes mellitus (DM) occurs when a dog’s body is unable to regulate their blood sugar levels, leading to symptoms such as weight loss, excessive urination, and lethargy. Diabetes insipidus (DI) occurs when antidiuretic hormone (ADH) fails to regulate levels of water and salt in the body appropriately, leading to excessive urination, dehydration, and increased thirst. Both humans and dogs can have diabetes mellitus and diabetes insipidus.

Diabetes mellitus (DM)

Diabetes mellitus, or sugar diabetes, is the form of diabetes that is most often referenced when discussing diabetes. It is a far more common form of diabetes in both dogs and people than diabetes insipidus. DM develops when the body is not regulating blood glucose levels appropriately due to either:

• A lack of insulin production (type I diabetes)
• Failure to respond to insulin (type II diabetes)

The body uses blood sugar, or glucose, for energy. The hormone insulin is produced in the pancreas and is needed to process glucose. When insulin is either not being produced or is not being responded to by certain cells, the body begins to break down fats and muscle tissue as a source of fuel instead. As a result, blood glucose levels remain elevated in the blood, and dogs begin losing weight as fats and muscle are broken down. The dog may become increasingly hungry as its body attempts to get energy from carbohydrates, even though it cannot process them properly. Diabetes mellitus is one of the most common hormonal disorders in dogs.

While diabetes mellitus is classified as type I or type II in people, there isn’t as much of a difference between the two types in dogs. Even though canine DM isn’t commonly referred to by its type, the form that occurs in dogs is more like type I diabetes in people.

Diabetes insipidus (DI)

Diabetes insipidus is a rare condition that develops when antidiuretic hormone (ADH) isn’t produced or processed correctly. In dogs with DI, ADH is either:

• Not being made in the brain
• Not being responded to by the kidneys

ADH alerts the kidneys to stop producing urine, helping to regulate hydration and electrolyte levels in the body. As a result, affected dogs continuously produce urine and can become severely dehydrated and have electrolyte imbalances that have extensive effects on the body.

Since diabetes insipidus is so rare, the word “diabetes” alone is usually assumed to mean diabetes mellitus.

DM and DI are very different medical conditions but share two common clinical signs: increased thirst and excessive urination. Other symptoms vary, as the conditions affect different parts of the body.

Additional clinical signs of diabetes mellitus in dogs include:

• Increased appetite
• Unexplained weight loss
• Lack of energy
• Blindness, cataracts, or cloudy eyes
• Unusual, sweet-smelling breath
• Loss of muscle mass
• Poor haircoat
• Abnormal hind limb posture and movement
• Intermittent vomiting or diarrhea

Dogs with diabetes mellitus are also more prone to recurring UTIs and skin infections.

The main symptoms of diabetes insipidus are excessive thirst and urination due to the constant production of urine that dehydrates the body. Dogs may need to urinate more frequently, urinate in large volumes, and have accidents around the home. Many dogs continue to act fine otherwise, but others may show lethargy, decreased appetite, and weight loss.

Is canine diabetes an emergency?

Diabetes mellitus is usually not an emergency, but it can eventually lead to emergency complications. When glucose cannot be used and the body begins breaking down fat tissue for energy, ketones are released into the blood. High levels of ketones lead to the blood becoming more acidic, a condition known as diabetic ketoacidosis (DKA). DKA can quickly become life-threatening. Clinical signs of diabetic ketoacidosis in dogs include:

• Severe lethargy
• Vomiting
• Lack of appetite
• Excessive panting
• Sweet-smelling or acetone-like breath

Dogs being treated with insulin therapy for DM can develop low blood sugar, or hypoglycemia. If blood sugar levels drop too low, it can become very dangerous quickly. Signs of hypoglycemia in dogs include:

• Severe lethargy
• Weakness
• Difficulty walking
• Loss of consciousness
• Lack of appetite
• Seizures

Each of these symptoms is a medical emergency and indicates a need for immediate veterinary care.

Diabetes insipidus can lead to severe, potentially life-threatening dehydration. Symptoms of dehydration in dogs include:

• Tacky or dry gums
• Sunken eyes
• Lethargy
• Loss of skin elasticity

It’s important for pet parents to closely monitor their dogs with diabetes and know the signs of emergency complications.

Diabetes mellitus is caused by inadequate regulation of blood sugar levels from either a lack of insulin or insulin resistance in the body. There are risk factors that increase a dog’s chances  of developing diabetes, including:

• Obesity
• Pancreatitis
• Cushing’s disease
• Hypothyroidism
• Genetics
• Long-term steroid use

Obesity is the greatest risk factor for dogs developing DM, so keeping a dog at a healthy weight through portion control and exercise is essential, especially in senior dogs.

Diabetes insipidus is caused by either inadequate production of ADH, the hormone that regulates the amount of water and salt in the body, or by a failure of the kidneys to respond to ADH. DI may be present at birth or acquired later in life. Risk factors for DI in dogs include:

• Head trauma
• Cushing’s disease
• Addison’s disease
• Liver disease
• Cancer or tumors in the brain or kidneys
• Infections
• Birth defects in the brain or kidneys
• Side effects of medications

DI remains rare even in dogs that have conditions that increase the risk of the disease.

What dogs are at risk for diabetes?

Older, obese dogs are the most likely to develop diabetes mellitus, though any dog of any age or weight can have the condition. Some breeds are more susceptible to the disease, including but not limited to:

• Miniature schnauzers
• Terrier breeds
• Cocker spaniels
• Samoyeds
• Cavalier King Charles spaniels
• Bichon frises

Female dogs are approximately three times more likely to develop diabetes mellitus than males. DM may also develop during pregnancy, but it’s usually temporary. Dogs with pancreatitis may develop DM due to destruction of insulin-producing cells in the pancreas, and the high levels of steroids that occur with Cushing’s syndrome can also lead to DM.

The risk of a dog getting diabetes insipidus is very low because the disease is so rare. Because the condition is so rare, predispositions are poorly understood. Very rarely, dogs are born with DI, but most acquire the disease later in life. Dogs who have sustained a head injury or take medications such as steroids or anticonvulsants are at a higher risk of developing DI.

The two forms of diabetes in dogs affect different parts of the body, so the diagnostic processes are different. Diabetes mellitus is often diagnosed by repeatedly obtaining high glucose level readings in blood and urine tests. Vets also take presenting symptoms, patient history, and current lifestyle into consideration. For an accurate diagnosis, a vet may recommend a blood glucose test after fasting. Dogs with DM have excess glucose in their system, even after not eating for a period of time.

Diabetes insipidus is very uncommon and the diagnostic process can be complicated in dogs. Because it is so rare, other conditions that have similar symptoms are ruled out first using diagnostic testing. Diagnostic tests may include:

• Blood tests
• Urinalysis
• Diagnostic imaging, such as X-rays or ultrasounds

If diabetes insipidus is suspected, a water deprivation test or ADH response test may be recommended to reach an accurate diagnosis. In a water deprivation test, urine is tested before and after withholding water for a few hours. In dogs with DI, urine will still be very dilute. Water deprivation tests require veterinary supervision because they can be dangerous for dogs with DI. In an ADH response test, the dog’s urine becomes more concentrated after receiving a dose of supplementary ADH. Another option for diagnosing DI is a therapeutic trial with the medication used to treat it.

The proper treatments for diabetes mellitus and diabetes insipidus are very different. DM is treated with:

• Insulin injections
• Weight management
• Change in diet or meal frequency

Most diabetes mellitus patients require daily insulin injections and close veterinary monitoring to keep their blood glucose at a healthy level. It’s extremely important to closely follow a veterinarian’s treatment plan and insulin dosage. An insulin overdose can quickly lead to life-threatening hypoglycemia, and unmanaged DM can lead to diabetic ketoacidosis.

Diabetes insipidus treatment varies depending on the origin of the condition. The form of DI caused by the kidneys not responding to ADH has no treatment and cannot be cured. The form of DI caused by a lack of production of ADH in the brain is treated with desmopressin, a synthetic form of ADH, or with diuretics, though treatment isn’t always necessary. Some dogs with DI may live a relatively normal life without treatment as long as they have unlimited access to water and are kept in an area where frequent urination isn’t a problem. Withholding water from a dog with DI in an attempt to reduce excessive urination can be life-threatening.

Does my dog need insulin injections at home?

Dogs with diabetes mellitus need insulin injections at home, usually after each meal. A vet can give you insulin dosing instructions and show you how to administer it. It’s very important to follow the directions for mixing, storing, measuring, and administering insulin closely. Complications with DM and insulin treatment can be rapidly life-threatening, so close monitoring and ongoing communication with a vet are crucial. A dog’s insulin requirements may change throughout their life, so dosages can change. An online vet can help walk you through administering insulin at home if more help is needed or if there is any confusion.

Dogs with diabetes insipidus do not require insulin injections.

Can diabetes be cured?

Diabetes mellitus is a lifelong condition. However, dogs can have a good quality of life with well-managed DM. Diabetes insipidus cannot be cured, and the outcome varies widely depending on the underlying cause. “Some dogs can be maintained simply by allowing unlimited access to water, although the resulting excessive urination may be difficult to cope with,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “Some underlying conditions are easier to treat than others, and DI doesn’t always go away even with effective treatment of the underlying cause.”

Increased thirst and excessive urination are the two most common clinical signs of both diabetes mellitus and diabetes insipidus. Talk to a vet if your dog shows these signs or any other symptoms associated with diabetes. Canine diabetes requires a definitive diagnosis before proper treatment can be given. Do not attempt to diagnose or treat a dog’s diabetes at home. Natural treatments do not work, and insulin can be extremely dangerous if not given properly. Never give a dog a dose of any type of insulin without a veterinarian’s instruction.

If you are concerned about your furry friend’s symptoms or need help administering insulin at home, an online vet on Vetster is glad to answer your questions and offer expert advice.

How do I know if my dog has diabetes?

The most common symptoms of both diabetes mellitus and diabetes insipidus in dogs are increased thirst and excessive urination. Other symptoms may include weight loss, lethargy, and a change in appetite. Diabetes in dogs requires an accurate diagnosis with a veterinarian.

How do you treat a diabetic dog?

Dogs with diabetes mellitus require daily insulin injections and likely a change in diet or meal frequency. Dogs with diabetes mellitus often do best with a strict feeding schedule and may benefit from a food formulated for diabetes or weight loss. Treatment for diabetes insipidus varies, and some dogs may not require treatment as long as they have unlimited access to water.

How long can a dog live with diabetes?

With proper management, dogs with diabetes can have a normal lifespan and a good quality of life. Complications from uncontrolled diabetes, such as low blood sugar or severe dehydration, can become rapidly life-threatening. These complications can lead to permanent damage to various areas of the body, even after the dog has been stabilized.

What foods should diabetic dogs avoid?

Dogs with diabetes mellitus should avoid foods high in sugar and fat. Excess sugar can lead to uncontrolled blood glucose spikes and drops, and fats are high in calories. Regular meals that are high in fiber and low in fat, including prescription diets for diabetes or weight loss, are commonly recommended for dogs with diabetes mellitus.