Veterinary Guide to Canine Insulinoma 2025 🩺🐶

By Dr. Duncan Houston BVSc

🧬 What Is Insulinoma?

Insulinoma is a rare but dangerous tumor of the pancreas that secretes excess insulin, causing persistent or episodic hypoglycemia (low blood sugar). It originates from the beta cells of the pancreas and often behaves malignantly in dogs, even when small in size. 🧪

👥 Which Dogs Are Affected?

Common in middle-aged to older dogs (6–14 years).
Breeds at higher risk incluade: Boxer, Irish Setter, German Shepherd, Golden Retriever, Standard Poodle, and Lab. 🐕
Neutered dogs are slightly more represented in studies.

⚠️ Signs of Insulinoma

Seizures 🧠
Collapse, fainting (syncope) 😵
Intermittent weakness or disorientation
Hindlimb trembling or wobbling
Behavior changes, anxiety, and pacing
Hunger, vomiting, weight gain (from insulin effects)
Symptoms often occur after fasting, excitement, or exercise 🏃♂️

🔬 Diagnosis

History & exam: Unexplained neurologic episodes or collapse episodes are red flags.
Blood glucose: < 60 mg/dL with concurrent signs of hypoglycemia.
Insulin level: Paradoxically normal or high insulin when blood glucose is low suggests insulinoma.
Insulin: glucose ratio: Calculated to support suspicion of insulinoma.
Ultrasound: May detect a pancreatic nodule or liver metastases.
CT scan or MRI: Used pre-surgically or when ultrasound is inconclusive.

🏥 Treatment Options

1. Surgical Removal

Pancreatic nodule resection: Partial pancreatectomy is preferred if the tumor is localized.
Staging: Liver, lymph nodes, and omentum checked during surgery for spread.
Success rate: 60–70% of cases achieve temporary remission or long-term control.

2. Medical Management

Diet: Frequent small meals rich in fat, protein, and complex carbs 🍗
Prednisone: Increases blood glucose by antagonizing insulin.
Diazoxide: Reduces insulin release from the tumor (not always available).
Octreotide: Somatostatin analog—reduces insulin secretion in some cases.

📈 Prognosis

Surgical + medical: Median survival is 12–18 months for most dogs.
Medical only: Median survival 6–10 months if surgery is not possible.
Recurrence is common due to microscopic metastasis.
Early intervention gives the best chance for remission. 💪

🧠 Managing Hypoglycemic Crises

Rub corn syrup or honey on gums for an immediate response if the dog is seizing or collapsing.
Call vet or emergency clinic—stabilization with IV glucose often required.
Do not give oral glucose to unconscious dogs (aspiration risk).

📱 Ask A Vet Telehealth Support

📷 Upload videos of collapsing episodes for remote vet assessment.
🔔 Medication & feeding reminders to prevent glucose dips.
📅 Lab check alerts for glucose monitoring every 1–3 months.

🎓 Case Spotlight: “Finn” the Poodle

Finn, a 9-year-old Standard Poodle, began collapsing during morning walks. Blood glucose was 44 mg/dL; insulin level was inappropriately high. An ultrasound revealed a 1 cm pancreatic nodule. Surgery removed the tumor, and biopsy confirmed an insulinoma. He returned to normal within 2 weeks and has been symptom-free on diet and low-dose prednisone for 14 months. His owners use Ask A Vet for weekly logs and glucose tracking 🐩💙

🔚 Key Takeaways

Insulinomas cause low blood sugar by secreting excess insulin; most are malignant in dogs.
Watch for episodic collapse, seizures, disorientation, or weakness.
Diagnosis is based on hypoglycemia + high insulin and imaging support.
Surgery is the best first option; medical therapy manages the remaining disease.
Ask A Vet telehealth helps track signs, manage diets, deliver meds, and prevent relapses 🐾

Dr Duncan Houston BVSc, founder of Ask A Vet. Download the Ask A Vet app today to guide your dog’s journey with insulinoma—track episodes, manage nutrition, monitor glucose, and access personalized veterinary support 🐶📲