Ferret Insulinomas

Ferret Insulinomas

by Dr. Sue A. Whitman, D.V.M.

Insulinomas (also called Islet Cell Tumors) are the most common tumor of ferrets. They are very tiny, yet powerful, tumors located in the pancreas. These cancers produce insulin in excess, resulting in low blood sugar. (You can think of insulinomas as the opposite of diabetes). Ferrets with insulinomas are usually wobbly in the hindquarters, usually have some weight loss, and are less active than they used to be.

Sometimes they will seem to be very mentally "distant" or will have moments when they stare into the distance. Many of these ferrets sleep more than normal, and in doing so, are missing meals, so will be most wobbly when they first get up (before eating). A few ferrets will salivate, and a few will vocalize often, but these signs are less common. Diagnosis of insulinomas is very simple. A vet needs to obtain a blood sample 1-6 hrs. after your ferret has eaten a meal. Timing here is important- it cannot be more than 6 hrs. after eating, or the test is not accurate. The vet should be able to test this blood sample for glucose (blood sugar) levels in the clinic, and get a diagnosis quickly. Normal ferrets have fasting blood glucoses ranging from 90 to 120 mg/dl. A ferret with insulinoma generally has a glucose level of 60 mg/dl or less.

The treatment of insulinoma requires surgical removal of the tumors (usually, there are 2-6 masses present). The earlier in the course of the disease the surgery is performed, the faster the ferret's recovery after surgery. If surgery is not an option, or cannot be done immediately, the ferret can be made more comfortable temporarily with medications. However, this will only provide short-term improvement, because if the tumors are not removed, they will continue to grow and secrete more insulin. Diet is also helpful: these ferrets must NOT have sugary foods, as this only stimulates insulin production and makes the situation worse. They should be fed high protein meals many times daily, until they can resolve the problem with a surgery. Examples of appropriate foods are: meat baby foods, COOKED eggs, Hill's Prescription A/D, cooked liver, and peanut butter.

If a ferret with insulinoma does not get veterinary care, they eventually have blood sugars so low that they go into a coma or seizure activity and die.

Although these tumors are malignant and usually do return, treated ferrets generally see about 13 months of happy, energetic life before recurrence. In my practice, once the insulinomas return, owners are offered either another surgical removal, or medications to manage the sugars for as long as possible. The owners and I make the decision as to which option to select when the tumors return based on the ferret's age and other health problems at the time.

If you have multiple ferrets, you will definitely have to deal with insulinomas at some point. In my own ferrets, I have been so overjoyed to see them happy and playful again after their surgical recoveries, that I would urge anyone with an affected ferret to give their pet that 12-13 mos. of gusto!

Sue A Whitman D.V.M.
8262 Switchboard Road
Spencer, Indiana 47460
812-876-0711
Emergencies call above number.