Insulinoma in Cats: A Vet’s 2025 Guide to Detection, Treatment & Care 🐱

Welcome! I’m Dr. Duncan Houston BVSc, veterinarian and founder of Ask A Vet. In this comprehensive 2025 guide, we’ll explore insulinoma in cats—a rare neuroendocrine tumor of the pancreas causing life-threatening hypoglycemia. You'll learn to recognize symptoms, understand in-depth diagnostics, evaluate surgical vs medical management, and provide compassionate at-home support.

📘 What Is Insulinoma?

An insulinoma arises from insulin‐secreting beta cells in the pancreatic islets. These tumors secrete insulin regardless of blood glucose level, leading to abnormally low sugar (hypoglycemia). While cat insulinomas are rare, they tend to be malignant and metastatic—highlighting the need for early intervention :contentReference[oaicite:3]{index=3}.

🐾 Who Is at Risk?

• Typically older cats—median age around 13 (range 5–17) :contentReference[oaicite:4]{index=4}
• No breed or sex predisposition identified, though ADULT to senior cats are most commonly affected
• Rare occurrence means each case is crucial to document

⚠️ Signs & Symptoms

Hypoglycemia manifests via:

• Seizures or tremors, especially when fasting or post-exercise
• Weakness, lethargy, incoordination, wobbling
• Excessive hunger, weight loss, sudden collapse
• Masks as neurological disease—misdiagnosis is common :contentReference[oaicite:5]{index=5}

**Important:** Recurrent unexplained seizures in middle-aged to senior cats should prompt testing for hypoglycemia!

🧪 Diagnostic Pathway

1. Initial screening: Check fasting blood glucose when signs appear. True hypoglycemia: < 45 mg/dL plus neuro signs.
2. Confirm labs: Low blood sugar with inappropriately high insulin, C-peptide & proinsulin :contentReference[oaicite:6]{index=6}.
3. Imaging:
   • Abdominal ultrasound / contrast-enhanced US (CEUS) may identify small nodules (~6 mm) :contentReference[oaicite:7]{index=7}
   • MRI/CT for precise localization & staging
   • Advanced scans (e.g. PET) rarely used in veterinary settings :contentReference[oaicite:8]{index=8}
4. Surgery & histopathology: surgical removal confirms diagnosis :contentReference[oaicite:9]{index=9}

🔍 Prognosis After Surgery

Surgical removal is the standard of care. In a retrospective study of 20 cats:

• 75% survived 1 year
• 51% survived 2 years
• 10% survived 3 years :contentReference[oaicite:10]{index=10}

These results highlight that early detection and complete tumor removal significantly extend quality life.

🛠️ Treatment Options

1. Surgery

Partial pancreatectomy + tumor excision is preferred. It provides:

• Immediate stabilization in blood glucose
• Tissue sample for histopathology & staging

2. Medical Management

For inoperable cases or when surgery is delayed:

• Frequent small meals—avoid fasting
• Prednisolone to raise blood glucose
• Diazoxide reduces insulin secretion—case report showed efficacy with side effects like vomiting & anemia :contentReference[oaicite:12]{index=12}
• Octreotide & glucagon infusions can assist in critical care :contentReference[oaicite:13]{index=13}

3. Chemotherapy / Palliative Care

Limited evidence in cats; sometimes combined with surgery to delay metastatic spread :contentReference[oaicite:14]{index=14}.

📈 Prognosis & Follow-Up

• Surgical cases: 1–2 years median survival; 10% reach 3⁠+⁠years :contentReference[oaicite:15]{index=15}
• Progressive tumors or metastases shorten survival
• Frequent glucose monitoring post-op—ideal = normoglycemia (85–120 mg/dL)
• Routine abdominal imaging every 6–12 months to check for recurrence

🏡 Home Care & Monitoring

• Provide frequent meals throughout the day and night
• Monitor fasting glucose with home glucometer
• Recognize early signs of hypoglycemia: lethargy, trembling, vision loss
• Always keep glucose paste or honey-ready for emergencies
• Track weight, appetite, and behavior in an ongoing diary
• Utilize Ask A Vet app for medication reminders and on-demand advice

⚠️ Case Study

“Max,” a 14-year-old cat with unexplained seizures, had fasting glucose of 42 mg/dL and elevated insulin. CEUS revealed a 6 mm islet tumor. Surgery returned glucose to normal, and Max remained symptom-free for 18 months with regular monitoring.

🚨 When to Seek Immediate Veterinary Care

• Recurrent seizures or collapse
• Bluish tongue, disorientation, lethargy
• Feeding-resistant hypoglycemia
• Suspected post-op complications: vomiting, anorexia, surgical pain

✨ Final Thoughts

Feline insulinoma, though rare, demands swift identification and treatment. With surgical excision, many cats achieve extended, quality life. When surgery isn't an option, a medical strategy—including diazoxide, steroids, and diet—can stabilize your pet. At-home vigilance, frequent feeding, and monitoring are key to success. Through Ask A Vet’s personalized plans, app support, and targeted advice, you’re not just treating a disease—you’re optimizing your cat’s life. 🐾❤️

Visit AskAVet.com or download the Ask A Vet app for custom care plans, glucose tracking tools, medication alerts, and expert veterinary support—every step of the way.