Dog Hyperglycemia: Causes, Symptoms, Diagnosis, and Management for Diabetic Dogs

Hyperglycemia refers to abnormally high levels of blood sugar (glucose) in dogs. Temporary elevations can occur, but persistent hyperglycemia often indicates an underlying health problem, with diabetes mellitus being the most common.

Causes of Hyperglycemia in Dogs

Diabetes Mellitus: This is the most common cause of persistent hyperglycemia. Diabetes occurs when the pancreas doesn’t produce enough insulin or the body’s cells become resistant to its effects. Insulin is crucial for regulating blood sugar.

Secondary Conditions: Various illnesses can cause hyperglycemia, including:

  • Cushing’s Disease (overproduction of cortisol)
  • Pancreatitis (inflammation of the pancreas)
  • Certain medications (steroids)
  • Severe infections or critical illness

Transient Hyperglycemia: Short-term blood sugar increases can be triggered by stress, excitement, or recent feeding.

Symptoms of Hyperglycemia in Dogs

The initial signs can be easy to miss. Be particularly watchful for:

Excessive drinking and bathroom trips: To counteract high blood sugar, your dog will drink more to try and expel the extra sugar through their urine. This leads to needing frequent bathroom breaks.

Weight loss despite normal eating: Even if your dog maintains their usual appetite, not getting enough energy from food will make them lose weight.

Reduced energy levels or unusual fatigue: Without glucose reaching their cells, dogs may have less pep in their step or seem more tired than usual.

Additional changes to watch for: These can include blurry vision (due to cataracts), more frequent infections, an oddly sweet or fruity odor to their breath, or vomiting.

Diagnosis of Canine Hyperglycemia

Dog Hyperglycemi
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A veterinarian will:

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Review Your Dog’s History: Pre-existing conditions, medications, and recent symptoms.

Blood Test: Measures blood glucose. A single high reading may indicate transient or persistent hyperglycemia.

Urinalysis: Detects glucose in urine, a hallmark of diabetes.

Additional Tests: May be used to rule out underlying diseases.

Treatment and Management of Hyperglycemia

Treatment depends on the cause:

Secondary Conditions: Treating the underlying illness often resolves hyperglycemia.

Diabetes Mellitus: Requires lifelong management:

  • Insulin Injections: To replace the missing insulin.
  • Specialized Diet: High-fiber, controlled carbohydrates.
  • Regular Exercise: Helps utilize glucose.
  • Home Blood Glucose Monitoring: To adjust insulin doses.

Living with a Dog with Hyperglycemia

With dedication and veterinary guidance, hyperglycemic dogs can live fulfilling lives. Key aspects include:

Regular Checkups: Monitor blood sugar and overall health.

Recognizing Emergencies: Learn the signs of dangerously low blood sugar (hypoglycemia) and diabetic ketoacidosis.

Owner Commitment: Consistent with insulin administration, diet, and monitoring.

Breed Predisposition

While hyperglycemia can affect any dog, diabetes mellitus (a common cause) is more likely in certain breeds. This includes:

  • Samoyeds
  • Miniature Schnauzers
  • Dachshunds
  • Poodles (especially Miniature Poodles)
  • Yorkshire Terriers
  • Beagles
  • Labrador Retrievers
  • Golden Retrievers

If your dog belongs to one of these breeds, be extra aware of potential hyperglycemia symptoms. Early diagnosis and management offer the best chance for a healthy life with diabetes.

Complications of Untreated Hyperglycemia

Dog Hyperglycemi
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Ignoring chronic high blood sugar opens the door to a range of health problems. Seeking veterinary care without delay is crucial to protect your dog from potentially severe consequences such as:

Cataracts: Persistently elevated blood sugar puts a strain on the eyes, potentially leading to cloudiness in the lens that can impair or even cause a loss of vision.

Increased Susceptibility to Infections: High blood sugar makes it harder for the immune system to fight off invaders. This can result in recurring skin infections, urinary tract infections, and other health issues that are more difficult to resolve.

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Nerve Damage: Long-term exposure to high blood sugar can harm nerves throughout the body. This might manifest as pain, weakness, or odd sensations (like tingling or numbness) in the limbs.

Diabetic Ketoacidosis (DKA): This urgent medical crisis arises when there’s not enough insulin available, forcing the body to burn fat for fuel instead. This produces harmful substances. Look out for extreme lethargy, vomiting, and a strange, sweet smell to your dog’s breath.


Unfortunately, not every case of hyperglycemia is preventable. However, some measures can reduce the risk, particularly for high-risk breeds:

Healthy Weight Management: Obesity increases diabetes risk. Provide your dog with appropriate nutrition and exercise.

Dietary Considerations: Discuss foods and feeding schedules that promote stable blood sugar levels with your vet.


Discovering your dog has hyperglycemia is understandably concerning, but it’s a symptom, not a final diagnosis. A veterinarian is crucial for determining the root cause and developing a tailored management plan. Many dogs with hyperglycemia live long, happy lives after receiving the right care.

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Frequently Asked Question

Is hyperglycemia always diabetes?
No, it can be caused by other conditions or be temporary. However, persistent hyperglycemia is a strong sign of diabetes mellitus.

Can hyperglycemia be cured?
It depends on the cause. If the underlying condition is treatable, resolving hyperglycemia may be possible. Diabetes requires lifelong management, not a cure.

What is a dangerous blood sugar level for a dog?
Veterinary advice is crucial. Generally, a blood glucose level above 250-300 mg/dL signals the need for concern, with levels above 400 mg/dL becoming increasingly dangerous.

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How do dogs act when their blood sugar is high?
They typically show increased thirst and urination, weight loss despite eating more, lethargy, and may develop cataracts or infections.

What are the signs a dog with diabetes is dying?
Signs including severe lethargy, persistent vomiting, collapse, labored breathing, and a sweet-smelling odor on the breath may call for urgent veterinary attention.

Can a dog’s blood sugar go up from stress?
Yes, stress can temporarily elevate blood sugar. This highlights the importance of veterinary evaluation to determine the cause of hyperglycemia.

What can I feed my dog with high blood sugar?
Never change your dog’s diet without consulting your veterinarian. Diabetic dogs generally benefit from specialized high-fiber, controlled-carbohydrate diets.

Can hyperglycemia in dogs cause seizures?
While uncommon, severely low blood sugar (hypoglycemia) is more likely to cause seizures. However, some chronic complications of hyperglycemia can potentially affect the brain over time.

How often should I monitor my diabetic dog’s blood sugar?
Your veterinarian will create an individualized blood glucose monitoring plan based on your dog’s needs.

Is there a natural way to lower blood sugar in dogs?
No, do not rely on natural remedies for hyperglycemia. These lack scientific support and could harm your dog. Always consult your veterinarian.

My dog has cloudy eyes. Could it be related to hyperglycemia?
Yes, cataracts can develop in diabetic dogs. Have your dog’s eyes checked by a veterinarian promptly.