Serious severity

Insulinoma (Pancreatic Tumour)

A rare tumour of the pancreas that pours out too much insulin, driving blood sugar dangerously low and causing weakness, tremors and seizures.

⚠️ Common symptoms

Episodes of weakness, wobbliness or collapse, often after fasting or exerciseMuscle twitching, trembling or full seizuresDisorientation, glazed staring or unusual dullnessIncreased hunger in some catsSigns that ease quickly after a meal, then return

Insulinoma is an uncommon but serious tumour of the pancreas in which the insulin-producing cells multiply and lose their normal restraint. Insulin's job is to move sugar out of the bloodstream and into the body's cells, so when a tumour churns it out relentlessly, blood glucose is pushed far too low. Because the brain runs almost entirely on glucose, the result is episodes of weakness, confusion, trembling and, in severe cases, seizures.

A telltale pattern is that signs often appear when the cat has not eaten for a while or has been especially active, and then ease within minutes of a meal — only to return later. This on-off quality can make the condition easy to miss at first, and owners sometimes assume the cat is simply tired or having an off day. Diagnosis usually rests on finding low blood glucose at the same time as inappropriately high insulin, backed up by imaging to look for the tumour.

Treatment aims first to stabilise blood sugar and then to tackle the tumour itself. Surgery to remove the affected portion of the pancreas offers the best hope where the disease has not spread, while medical management with frequent small meals and medications such as steroids can keep many cats comfortable for a good while. With attentive care and close monitoring, affected cats can enjoy a reasonable quality of life, but the condition needs lifelong vigilance.

🔍 Causes

Insulinoma is caused by a tumour arising from the insulin-producing beta cells of the pancreas. These cells ignore the body's normal signals and keep secreting insulin even when blood sugar is already low, so glucose is driven down to levels that starve the brain and muscles of fuel. It is uncommon in cats and the underlying trigger for the tumour is not well understood.

🛡 Prevention

There is no known way to prevent insulinoma, so the priority is early recognition. Any cat with unexplained episodes of weakness, trembling or seizures — especially if they ease after eating — should be investigated promptly, because catching the disease early gives the widest choice of treatments.

💊 Treatment

Emergency low blood sugar is corrected first, with the owner rubbing a little honey or glucose syrup on the gums on the way to the clinic and the vet giving intravenous glucose. Longer-term management centres on surgery to remove the affected part of the pancreas where possible, which can give the best results. When surgery is not an option, frequent small meals and medication such as steroids (and sometimes diazoxide) are used to keep glucose from crashing. Careful monitoring of blood sugar guides treatment.

When to see a vet: Seek veterinary care urgently if a cat has a seizure, collapses, or becomes repeatedly weak, wobbly or disoriented, particularly when these signs improve after food. Recurrent low-blood-sugar episodes are a medical emergency and need prompt investigation.

⚕️ Medical disclaimer

  • This information is educational only and is not a substitute for veterinary advice.
  • Symptoms overlap between conditions — only a vet can diagnose accurately.
  • Never withhold treatment or self-medicate based on information found online.
  • When in doubt, call your vet. Early intervention almost always leads to better outcomes.

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