Insulinomas are the most common tumor in the ferret. Insulinomas produce excess insulin which creates problems for the ferret. Insulin is a hormone that allows most of the cells in the body to utilize the glucose in the blood. The excess levels of insulin produced by these tumors drive the glucose in the blood into the cells of the body, causing a dangerously low blood glucose level, known as hypoglycemia or low blood sugar.

Hypoglycemic ferrets may exhibit a wide range of clinical signs. Weight loss appears to be a common finding in affected animals, and may be the the only sign. This is a reason why you should weigh your pet regularly as part of a good preventive health program. Signs that are more diagnostic of insulinomas are :

• weight loss
• depression
• lethargy
• weakness
• salivation
• difficulty in using the hind legs
• vocalization
• seizures in severe cases

Diagnosis

Insulinomas are diagnosed primarily by measuring the blood glucose levels in the ferret. We recommend screening with a blood sugar on a routine six month interval. Animals with blood glucose levels less than 60 mg/dl nearly always have one or more of these tumors in the pancreas. Exploratory surgery (insulin levels may be checked for confirmation) should be scheduled at the earliest possible time. Ferrets with a glucose of 60mg/dl to 70 mg/dl should have insulin levels performed.

Treatment

In animals where surgery is not an option, or until such a time as surgery is possible, medical management may be attempted by using medication aimed at increasing the blood glucose and decreasing the insulin levels. It is important to realize that this is only a temporary measure and rarely is effective in controlling the animal's hypoglycemia for a long period.

Important Note

While insulinomas are not considered malignant tumors, a large number of cases will eventually develop additional tumors. As a general rule, this occurs anywhere from one to four years. I have, in some cases, operated on ferrets three times for insulinomas that occurred in their lifetime. Also, when exploring ferrets for insulinomas, it is not uncommon to find other types of tumors that need to be addressed.