Insulinoma - How to Recognize It and Emergency Treatment
Contact Us

  by Beth Burns

Beth Burns via consultation with Dr. Charles Weiss

Insulinomic ferrets may just act a little tired, lethargic. The only symptom our ferret Miska showed in 1995 was a little increased flattening. Their back legs may wobble. They may seem "out of it" and stare at nothing. They may feel nauseous. Some let you know by pawing at their mouths. More severe symptoms include seizures or comas, which are life threatening, of course.

If an Insulinomic ferret is comatose, having a seizure, can't use its back legs or is very wobbly, quickly rub karo syrup on the gums. Honey may be substituted if you don't have karo syrup. Use a q-tip to avoid being bitten if the ferret is seizing. Many ferrets will become alert and act normal within a minute.

Follow the karo syrup with a high protein meal (kibble or duck soup without sugar) to help stabilize the blood glucose. Contact a ferret knowledgeable veterinarian.


Karo syrup is preferable to honey; it can be utilized more quickly. When you give an influx of sugar - in this case karo or honey - it will quickly raise the blood sugar and the ferret may feel much better, but what goes up must come down, and the blood sugar will soon fall back to its previous level - or lower. Using karo or honey as ongoing treatment means that preferred treatments are being withheld from a sick ferret and the ferret may be suffering needlessly.


Surgery is usually the preferred treatment. In the hands of a skilled surgeon, a partial pancreatectomy can give increased lifespan, and often no medicine is needed for a time, even years. A partial pancreatectomy is removal of the tumor(s) and part of the pancreas. Until recently, surgeons just removed or "popped" the tumors. The earlier the partial pancreatectomy is done, the better the results, so don't wait. Your ferret can do well on medicine, sometimes for a long time, if surgery cannot be done.


Sadly, there is no absolute cure, and even mild insulinoma will always get worse as tumors grow or seed into new ones. But with the right care, an Insulinomic ferret can live comfortably and happily for years, and depending upon when they get sick, may live out a normal lifespan.

If the ferret's insulinoma is caught early and if surgery (the partial) is done quickly, results can be great. Miska got insulinoma in 1995 and was medicine free until mid 1998. Dr. Tom Kawasaki and Dr. Charles Weiss did her surgeries, both partial pancreatectomies.

Blood Glucose - the Numbers

Quick quiz: A ferret has a fasting blood glucose reading of 90. Normal? Or suspicious?

Many veterinarians and experienced owners might say 90 is normal. But the blood glucose test that alerted us that Miska's insulinoma had returned was 89. Until recently, blood glucose readings in the 80s or 90s were considered normal, and even as low as the 70s. In actuality, a blood glucose level even as high as the low 90s may indicate an early insulinoma, depending on the ferret's history, testing pattern and other symptoms.

The Insulinomic ferret, regardless of treatment selection, should have a blood glucose test every 4 to 12 weeks. The test should be read in the veterinarian's office, not sent out to a lab. It only takes a couple of minutes. Because they have had insulinoma for quite some time, our ferrets all have 4-week interval blood glucose tests. A test should be done two weeks after surgery, and frequently for some time. After that, intervals can be a little longer, assuming the blood glucose range stays high - say in the 100s.

The Miska example: Since her first surgery, Miska's fasting (3-4 hours) blood glucose levels were always between 100 and 114, so 89 represented a significant drop. But even small incremental drops should be taken seriously, and tests repeated weekly or biweekly if necessary.

Miska had a second surgery and maintained fasting blood glucose levels in the 100s until mid 1998. The insulinoma returned at that point, and she is active and comfortable, taking PediaPred (prednisone for children) every day. She was tested every 8 weeks, and now is tested every 4. Her last two tests were 98 and 96. At some point her symptoms will worsen, her blood glucose will drop and her PediaPred dose will probably be increased. Proglycem may be added, if she can tolerate it - it makes some ferrets nauseous.

Ulcers and Pred

PediaPred should always be given with food, as it is upsetting to the stomach. Ulcers should be watched for. Signs can be grinding and increased flattening showing discomfort (also a sign of lethargy). Ulcers can be easily treated with antibiotics and Carafate - generally .5 cc's of Carafate 4 to 6 times a day. Dr. Weiss does not recommend the use of Pepto Bismol, and has found that sufficient Carafate (and antibiotics) works quickly, without causing the stress that Pepto can. Carafate should be given 20 minutes after antibiotics, so it won't interfere with absorption. If you don't have 20 minutes, try to wait 5 or 10. Because ferret motility is so fast, there is no need to wait much longer.

Miska has not had a problem with ulcers, probably because she eats her "cereal" every morning before being given PediaPred. Miska's cereal is simply kibble with a little purified water poured on it, micro waved until luke-warm. Don't use tap water from the hot-water tap. If you use tap water, let the cold water run for some time before using.

Down with Raisins (sigh)

No sugar for Insulinomic ferrets! What is sugar or has sugar in it? Raisins, Pedialyte, Petromalt, Ensure, Nutrical, Sustical, fruit, honey, or anything that has an ingredient with the letters "ose" at the end. A caveat is that if a ferret has had a "successful" partial pancreatectomy, for a time that ferret can be considered normal, and very small amounts of sugar probably won't hurt. I've been able to give Miska cheerios, which have very low sugar, as treats throughout the years, although they are not recommended for ferrets who aren't maintaining normal (90s,100s) blood glucose levels. Basically, sugar causes the blood glucose of an Insulinomic ferret to zoom way up and then crash very low.

Our Insulinomic ferrets aren't allowed a cheerio unless they have recently eaten a high protein meal - kibble or duck soup made almost entirely from kibble. Sugar should not be given when their stomachs are empty. We never give raisins or fruit. Ever.

Something to think about: For those of you who regularly give your non-Insulinomic ferrets sugar (raisins included), you might want to consider that insulinoma can stay hidden for a long time. That means sugar is being given to Insulinomic ferrets.

Treats and Helping Stabilize

To help stabilize blood glucose, give frequent meals and high protein snacks. You can hand feed ferrets their regular food - it seems to taste better that way. We keep kibble in every room of the house in little dishes up on tables and hand them pieces as they go by. We also treat them with cat/kitten kibble; ours like Authority, sold by PetSmart. Make sure you're feeding them a high protein kibble, like Totally Ferret. We were told by Dr. Willard of Totally Ferret not to switch our two Insulinomic seniors to the senior food, which has lower protein.

Many people swear by adding chromium and brewers yeast to the diet. Dr. Weiss used to recommend that, but over time has not seen any evidence that there is a difference between ferrets who were given supplements and those who were not. It can't hurt, just don't rely on them as treatments.

Looking Ahead and Monitoring

When a healthy ferret is two or at the latest three years old, getting a fasting blood glucose test will give you a baseline or even could uncover an unsuspected insulinoma. Then, depending on your ferret's age and lineage, testing every six months to one year will allow you and your veterinarian catch the disease early; sometimes the numbers will tell you even before the symptoms begin.

If blood glucose tests are not conclusive, an insulin test can be done. It's about 50% accurate, unfortunately. If it's positive, it's accurate. If it's negative it may or may not be. The blood glucose test can be repeated with a longer fast, but not usually longer than 5 hours. If the blood glucose is borderline, but there are symptoms, it is likely insulinoma is present. If a ferret has symptoms, be very cautious about fasting. Lengthy fasting can cause a severe drop in blood glucose, and even seizures.

Backwards Treatment?

Too often, it seems that treatment is done backwards. Typically, the ferret gets symptoms and is put on medicine, and only after the medicine stops working is surgery done. At that point the surgery may not seem to help all that much, so people say that surgery isn't valuable. But during the time the ferret was on medicine, tumors were growing. Surgery needs to be done as early as possible, not as a last resort - though even then, it may help. Of course, how skilled the surgeon is makes a difference. For a time after a successful partial pancreatectomy, the ferret can be totally insulinoma free. Surgery gave Miska a high-quality life without medicine or symptoms from 1995 to 1998, and quite obviously has extended her lifespan considerably.

Partials are Harder

Partial pancreatectomies are trickier than simple tumor removal, though a good surgeon can learn by talking through the procedure with veterinarians who have been doing this procedure for some years. Location of the tumor(s) in the pancreas also influences how difficult the surgery is. And tumors can be very difficult for an inexperienced surgeon to find. That presents a serious problem for the owner - and ferret - with no easy answers.

Getting the Word Out

Why don't many veterinarians know about the latest treatment? Often veterinary schools don't change their curriculum until a study is published, and the word is slow to get around, though information was presented at recent annual Ferret Veterinary Symposiums in Baltimore, Maryland. And sadly, some vets who say they are ferret knowledgeable, are not, or were at one time, but have not aggressively kept up with newer treatment methods.

Insulinoma Study Complete and Published!

Hopefully this study will help get the word out about newer treatment methods and combat an insulinoma myth that surgery "doesn't work."

Charles Weiss, DVM, recently completed a study on insulinoma that was published in the Journal of the American Animal Hospital Association, November/December, 1998, Volume 34, No. 6, 471-5. Also listed - Bruce Williams, DVM. Title: Insulinoma in the Ferret: Clinical Findings and Treatment Comparison of 66 Cases. Call 1-800-883-6301 for a free copy of the article. If you want to see the photos in color, you can buy a copy of the journal itself for $15.00/non-members, $10.00/members.

More Help is Available

My E-mail address is   Dr. Weiss gets calls from many veterinarians who consult with him about insulinoma and other ferret diseases (he has also conducted adrenal studies and has done successful bilateral adrenalectomies), and is glad to do so. Here is his office number to give to your veterinarian: (301) 299-4142, in Maryland.

[webmaster's note: this article is a number of years old and it is very likely that the listed email address and phone numbers are no longer valid]

Magic Potions

Sometimes people make claims about supplements and mixtures that do not appear to hold up under scrutiny. While people say their ferrets were kept alive for X amount of time, remember, ferrets would ordinarily live X amount of time anyway. Sugar/honey exacerbates this illness; good diet and FREQUENT high protein feedings help stabilize the blood glucose, but the only actual treatment that can considerably prolong length of life appears to be surgery (as early as possible) followed by medicine or a second surgery in some cases.

Surgery 101 - The Basics

Fasting should not be longer than 3 hours before surgery. The pre-operation fasting time may have to be even less and more closely monitored if the ferret is severely Insulinomic. On occasion glucose must be administered to keep the ferret stable, if symptoms are severe. Isoflurane is the ONLY anesthesia that should be used, not Ketamine or any other. And often the shorter the time under anesthesia the quicker the recovery. Surgeries lasting two to three (or more) hours can slow recovery markedly.

Post-surgery fasting is generally 14-18 hours. Ferrets should be given sub-q fluids and pain medication after surgery is complete. Dr. Weiss' ferrets usually go home the day of surgery, in order to reduce stress. They are often given a pain shot and more sub-q fluids just before they leave. That is generally the only pain medicine they'll need, though a quarter of a tablet of torbutrol is sometimes given at home (if they need it) about 12 hours post-op.


Whatever you do, please don't wait to get treatment for this illness. It is not forgiving. Insulinoma can get worse even in a couple of weeks. A month can be a long time.

Good luck and all the very best for your cherished little ones -

Beth Burns and David Burns - plus Miska (insulinoma survivor since 1995), Pads (insulinoma survivor since 1998) and Gabby (insulinoma survivor since 1997)