Surgery Removes Feline Pituitary Tumor, Ends Insulin Need

Owners of cats with complex endocrine issues may find a new path to health through advanced surgical interventions.

Updated on Oct. 21, 2026 in Pet Health

Gouache-painted illustration of a cat silhouette with a soft internal glow, representing the successful outcome of a recent veterinary procedure. — A 10-year-old cat named Mars successfully ended daily insulin injections following a specialized pituitary tumor surgery in Bend, Oregon, in May. AI Illustration. Upload story photo >

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In May 2026, a 10-year-old cat named Mars underwent a specialized pituitary tumor removal at the Veterinary Referral Center of Central Oregon in Bend. The complex procedure successfully addressed the cat's severe insulin resistance, eliminating the need for high-dose daily injections.

Why it matters

Pituitary tumors in cats can lead to life-threatening insulin resistance by causing the gland to overproduce growth hormone, necessitating advanced surgical intervention when medication fails. This case highlights how specialized neurosurgery can restore metabolic health and mobility in aging pets.

The surgery corrected extreme insulin resistance in a 10-year-old cat, moving the patient from 20 units of daily insulin to normal levels. The procedure required drilling a 6-millimeter access hole to reach the pea-sized gland.

The players

Dr. Annie Chen-Allen

A veterinary surgeon who performed the operation and previously spent 17 years teaching at Washington State University.

Veterinary Referral Center of Central Oregon

The Bend-based specialized hospital providing complex veterinary surgical care.

The details

The surgical team utilized a 3D camera to visualize the small, pea-sized pituitary gland through a 6-millimeter access hole drilled in the skull. This specialized approach addresses the root cause of growth hormone overproduction that renders standard medications and radiation ineffective. Patients recovering from this procedure require long-term post-operative care, including thyroid management and lifelong steroid supplementation.

May 2026: The surgical team performed the tumor removal at the Bend facility.

The Home Front

Advanced surgical techniques once reserved for human medicine are increasingly available for pets facing complex endocrine disorders. This evolution in veterinary technology allows pet owners to seek high-level interventions for previously terminal or unmanageable diagnoses.

Pet owners noticing sudden, extreme changes in insulin requirements should consult with a specialist about potential underlying endocrine tumors. Discuss the feasibility of advanced diagnostics if standard medication plans fail to stabilize your pet's metabolic health.

The takeaway

Advanced neurosurgical techniques can provide a path forward when routine treatments for feline hormonal disorders fail. Discuss your pet's current medication protocol with your veterinarian to determine if hormonal resistance warrants a referral to a specialist.