Insulinoma is one of the most common forms of cancer diagnosed in ferrets. It’s a common misconception that insulinoma is a ferret’s version of diabetes, but in fact, insulinoma is the exact opposite of diabetes for ferrets.

A ferret with insulinoma has cancer of the pancreas, which is when Islet cell tumors on the pancreas cause an overproduction of insulin. Insulin is a hormone which allows cells in the body to use glucose in the blood. Overproduction of insulin forces the glucose in the blood into the cells, which causes a drop in glucose level, or hypoglycemia. Diabetes in ferrets is when low levels of insulin render cells unable to use the glucose, causing an overabundance of glucose. This is known as hyperglycemia.

So to summarize:

Hypoglycemia = too much insulin = low blood sugar = Insulinoma
Hyperglycemia = too little insulin = high blood sugar = Diabetes

A normal blood sugar level for a ferret is anywhere between 90 and 120. When a ferret has low blood sugar (anything 70 or below), this is considered to be diagnostic of insulinoma. A blood glucose test can be administered by your vet, but what symptoms should raise the alarm?

  • Weakness
  • Lethargy
  • Excessive Salivating
  • Staring off with a dazed look
  • Mouth ulcers
  • Tremors, twitching or head bobbing
  • Pawing at the mouth
  • Hind leg weakness (this is one of the most common signs that is almost always attributed to insulinoma)
  • Loss of coordination
  • Vomiting
  • Lack of appetite
  • Weight loss

If your ferret is exhibiting one or more of these symptoms, a visit to an experienced ferret vet and a blood sugar test are highly recommended. You can do a fasting blood sugar test (no food for 3 – 4 hours) or a regular blood sugar test. It is advisable that if your ferret has already had a seizure that you just do a regular blood glucose test.

If you see these symptoms and they stop, don’t assume that your ferret is alright. Insulinoma symptoms can come and go as their blood sugar rises and falls. Things that trigger these changes in blood sugar are diet, exercise & stress.

Even if you aren’t seeing symptoms, routine blood work (including the blood sugar test) is also recommended during annual vet visits for ferrets 3 years and older. As with other ferret diseases and health issues, insulinoma is more easily treated the earlier it’s caught.

So your ferret has been diagnosed with insulinoma – what can you do? You have a few different options.

1) Surgery – either to remove any pancreatic masses or a full pancreotomy. This will stop or slow the progression, but it is rarely a cure. Pancreatic tumors are small and seedy nodules, generally located throughout the pancreas of an insulinomic ferret. The chance that a vet will get all of the tumors is unlikely, and they will probably come back. However, in a study done by Dr. Bruce Williams, a pancreotomy gave the ferrets a 33% longer survival and disease free interval. (When compared to just medical treatment, ferrets given a pancreotomy were disease free for 365 days as compared to 22 days, and survived 668 days as compared to 186 days.)

2) Medication – surgery is not always the best option for older, unhealthy ferrets, and sometimes it’s not an option at all, due to money issues or ferrets with conditions that prevent it. The most common medications used to control Insulinoma are Prednisone, diazoxide (Proglycem), and dexamethasone. Prednisone raises the blood glucose and increases the production of glucose in the liver. It doesn’t, as some people think, block the insulin. Rather, it counteracts the hypoglycemic effects of insulin with hyperglycemic action, effectively balancing it out. For best results, medicine should be given twice a day, 12 hours apart, to keep the glucose levels as stable as possible.

3) Diet Change – this is recommended regardless of whether you choose surgery, medication, or both. Ferret diets higher in animal protein help insulinomic ferrets to lead a more symptom free life, as protein helps to regulate and raise blood sugar levels. Frequent feedings of duck soup can be very beneficial, whether you make your duck soup from canned A/D (prescription diet from the vet) and baby food, or from boiled chicken.

What precautions should you take as the parent of a ferret with insulinoma? First, always keep something around to bring your ferret out of a seizure! This can be Karo syrup, honey, or maple syrup – something high in sugar that you can smear on their gums to stabilize them. This should only be given in the event of an insulinomic episode! Sugary treats and foods should not be given. Seizures are probably going to happen as the disease progresses, so make sure whatever you use is easily accessible. Your ferret could need up to 40 minutes to fully recover from a seizure, and should be fed a high protein food (baby food, A/D) as soon as he or she is alright enough to eat.

To help prevent or anticipate seizures, you can keep track of your ferret’s blood sugar levels by purchasing a Blood Glucose Monitor, such as a BD Logic or a Freestyle monitor. These are the same monitors used to track blood sugar in humans, so they probably aren’t going to be right on. The best way to figure out the reading is to take one the first time in the vet’s office while the vet does a reading as well. That way you can figure out if it runs low or high. Take your ferret’s blood sugar at home on a regular basis so you will know when to expect low glucose levels. By doing this, you can anticipate episodes.

Lastly, make sure the feedings and doses of medication are given on a regular basis. This is very important to keep your ferret stable! Medication should be every 12 hours, feeding at least every 12, or more often as the ferret needs it. Feeding your ferret before dosing can help in the long run, as prednisone and other drugs used to treat insulinoma can cause ulcers if given on an empty stomach.

Insulinoma is very common in ferrets, but there is one thing you can do to lessen the possibility that your ferret will become insulinomic. Sugar intake has been tentatively linked to causing insulinoma, so avoiding sugary treats, fruits & vegetables may help to prevent your ferret from developing insulinoma. Unfortunately, this is really the only thing you can do, and it may or may not work. However, since ferrets are obligate carnivores that get their nutrition from animal proteins and fats, avoiding sugar is a good thing to do anyway!

Though insulinoma is a disease that is going to cause some necessary life changes for you and your ferret, the outlook could be a lot worse. If cared for properly, many insulinomic ferrets can live long and happy lives, untouched for the most part by symptoms or episodes. The cause of death for ferrets that have insulinoma is often a disease or health issue other than the insulinoma. The most important thing you can do is remember that your ferret depends on you for treatment, for diagnosis. Know the symptoms of insulinoma, and how to care for it should your ferret be diagnosed.