Insulinoma or pancreatic beta cell tumor is an abnormal growth of the pancreas that secretes excessive amounts of an hormone called insulin. Insulinoma is an extremely common disease of middle-aged to older ferrets. As insulin levels rise, blood sugar or blood glucose levels fall causing symptoms to appear. Blood sugar is needed for the brain to function and for muscles to work normally.

Clinical signs

Signs of falling blood glucose levels in the ferret may be very variable and include a dazed, glassy-eyed stare, lethargy, weakness, to even collapse and seizures. Low blood glucose levels or hypoglycemia can also manifest as rear leg weakness and/or wobbliness in the ferret. Hypoglycemia is also often associated with nausea in the ferret. A nauseous ferret may drool or paw at its mouth vigorously.

Diagnosis

Insulinoma is so common in the older ferret that persistently low fasting blood glucose is highly suggestive of disease. High blood insulin levels are used in rare cases to confirm the diagnosis. Unfortunately ultrasound or radiography are rarely helpful for the diagnosis as the pancreatic nodules are so small that cannot be identified. A definitive diagnosis is usually obtained with a surgical biopsy.

Therapy

The treatment of choice for insulinoma is surgical removal of the pancreatic tumour. Unfortunately there is no way to remove all tumour cells surgically. Even if entire sections of the pancreas are removed, signs of insulinoma will eventually recur. Within weeks to months, in rare cases years, medical management becomes necessary. The current medication of choice for managing insulinoma is the steroid, prednisolone. Prednisolone helps the body make blood sugar but it also has many side effects. Eventually prednisolone alone is not enough to control signs of hypoglycemia, and a second drug, diazoxide may be added. For a time, prednisolone and diazoxide controls the signs of hypoglycemia, but eventually they are no longer sufficient. Although there are experimental drugs available, there is no consistently reliable third medication that may be offered. Often the ferrets will present in a collapsed state so initial periods of hospitalisation and intensive treatment are often needed.

Prognosis

Although surgical and medical management may control signs for a time, there is no known permanent cure for insulinoma. Eventually insulinoma leads to the death of the affected animal.

Home care

1. Give all prescribed drugs as directed. Prednisolone frequently increases water intake and appetite, so fresh water and litter trays must always be available.
2. Provide high quality, high protein ferret or cat food and make sure this is available free throughout the day. Avoid semi-moist foods or sweet snacks as well (raisins, corn syrup, sugar, molasses, fructose or anything containing any of the above) which are high in sugar. If the ferret is not eating on its own, the owner must hand feed a high protein, high fat and low sugare meal every 4-6 hours. Ferrets are notorious for their “sweet tooth”. Offering a ferret with insulinoma a sweet snack is analogous to a person eating a candy bar. First a “sugar high” occurs and the person feels full of energy, but this is followed by the all too familiar “crash” or decrease in blood sugar. The ferret with insulinoma does not have the reserves to handle such a crash and severe signs of hypoglycemia may occur such as collapse or seizures.
3. Some situations (such as excitement, exercise, or stress) may lead to increase utilization of blood sugar and sudden appearance of symptoms. Be ready to recognise these situations and reduce their occurrence. Encourage your pet to eat a high quality protein, high fat, low carbohydrate/sugar snack after exercise, excitement, and/or stress.
4. If signs of hypoglycemia (weakness, lethargy, drooling, pawing at the mouth) are observed at home, encourage your pet to eat a small high protein meal since this will help to stabilize blood glucose levels. If severe weakness, collapse, or even seizures are observed and your pet is not capable of eating, rub sweet syrup on the gums. Take care of being bitten if seizures are observed – use a cotton tipped applicator rather than your fingers. Once your pet is more alert, feed a high quality, high protein meal such as kibble or Lafeber Company’s Emeraid Carnivore. contact your veterinarian immediately if signs of hypoglycemia persist or if seizures or collapse are observed. A ferret should not be transported during an active seizure unless the administration of glucose on the gums has not controlled the seizure.
5. Consider keeping a log that records episodes of hypoglycemia. This will help your veterinarian to best evaluate the efficacy of your ferret’s medication(s).

Insurance

Unfortunately there is no health service provided for exotics. Many pets may develop long term illnesses which may require a long term treatment. A pet insurance would take the financial strain of this off your shoulders so think about getting your pet insured asap.

Emergency

• We offer first and second opinion consultations. For the more unusual and/or complex cases your vet may decide to refer your pet to us.
• For any information or concerns, please ring our veterinary hospital on 01275 838473 or 01275 832410.