🧠 Insulinoma in Dogs & Cats: 2025 Vet Diagnosis & Treatment Guide

By Dr Duncan Houston, BVSc

Insulinoma is a rare but serious condition affecting pets—specifically a tumor of the insulin-producing beta cells in the pancreas. This small gland, located beneath the stomach, plays a critical role in blood sugar regulation. When an insulinoma develops, it causes the body to produce excess insulin, which can drastically reduce blood sugar levels and trigger seizures or collapse. 🐶🐱

🔬 What Is an Insulinoma?

Insulinomas arise from the beta cells within the pancreas. These tumors produce insulin even when it’s not needed, disrupting the body’s ability to maintain stable blood glucose levels. While the tumor itself may be small, its impact is profound due to the powerful metabolic effects of insulin.

📉 Symptoms of Insulinoma

Signs of insulinoma are typically due to hypoglycemia (low blood sugar) and may include:

• 💥 Seizures
• 😵 Weakness or fainting
• 🧍‍♂️ Wobbliness or "drunken" gait
• 😴 Lethargy
• 🍽️ Loss of appetite
• 🧠 Mental dullness

These episodes may come and go but become more frequent and severe over time.

🧪 Diagnosis

Diagnosis begins with identifying low blood glucose levels on routine bloodwork. To confirm insulinoma, your vet will often run:

• 🔬 Insulin levels (must be done while blood sugar is low)
• 🧫 ACTH stimulation or cortisol test (to rule out Addison’s disease)
• 🩸 Bile acids test (to evaluate liver function)

🖥️ Imaging Tests

Once insulinoma is suspected, imaging is needed to locate the tumor and evaluate for metastasis (spread):

• 🔍 Ultrasound: Detects masses in 75% of cases
• 🖼️ CT scan: Preferred if available; offers higher sensitivity

📊 Staging & Prognosis

The tumor is staged to determine how far it has spread:

• 🎯 Stage I: Localized to pancreas
• 🔁 Stage II: Spread to local lymph nodes
• 🌍 Stage III: Spread to distant sites (e.g., liver)

⏳ Prognosis varies—dogs with Stage I-II can live 1–2 years post-surgery, while Stage III cases have shorter lifespans (under 6 months).

✂️ Surgery

🎯 Surgery is the treatment of choice. It involves removing part of the pancreas. However, surgical risks include:

• ⚠️ Blood sugar swings
• 🔥 Post-op pancreatitis
• 💉 Temporary need for insulin post-surgery

With successful surgery, dogs can enter long remissions—up to 1.5 years or more!

💊 Medical Management

If surgery isn’t feasible, treatment focuses on managing low blood sugar:

• 🧃 Frequent small meals
• 💊 Prednisone: Boosts blood glucose
• 💊 Diazoxide: Suppresses insulin release (most effective drug)
• 🍬 Emergency: Apply Karo syrup or Nutri-Cal® to gums during episodes

💉 Chemotherapy Options

For confirmed malignant cases, chemotherapy drugs can slow progression:

• 💊 Streptozocin: Targets pancreatic beta cells
• 💊 Toceranib (Palladia®): An emerging option
• 💊 Doxorubicin or alloxan: Sometimes considered

Talk to a veterinary oncologist to explore the best treatment protocol. 🧬

📅 Long-Term Outlook

⏳ Without surgery, average survival is 6 months. With surgery and/or medications, survival extends to 1–2 years or more in some cases. Lifespan depends on staging and tumor behavior.

📱 Ask A Vet: Your Partner in Pet Health

Insulinoma can be a frightening diagnosis, but you're not alone. For ongoing care, episode management, and guidance, download the Ask A Vet App today and connect with licensed veterinarians 24/7. 🐾

Stay informed. Stay empowered. Your pet deserves it. ❤️