Hypoglycemia is a term used to describe a blood sugar concentration of less than 70 milligrams per deciliter (mg/dl) of blood. In ferrets, this is most commonly caused by an insulinoma, a tumor of the pancreas. These tumors produce large amounts of insulin, which causes the blood glucose (sugar) to drop below normal levels, resulting in symptoms of generalized weakness progressing to severe illness and seizures. The cause of insulinoma is poorly understood, but it appears to affect the pancreas of older ferrets. Ferrets who are diagnosed with insulinomas require treatment for the remainder of their lives.
What to Watch For
Insulinoma, and the associated hypoglycemia, is common in ferrets over 3 years old, and both males and females are at risk. For some ferrets onset can be subtle, while others appear normal until they collapse or they begin having seizures. Symptoms of hypoglycemia are mild initially, but they become increasingly worse as the disease progresses. If your ferret shows any of the following signs, contact your veterinarian.
Weakness and sluggish behavior
Increased amounts of sleeping
Standing still and staring blankly
Episodes of drooling
Difficulty walking, especially in the rear legs
Your veterinarian will want to perform some diagnostic tests in order to determine if insulinoma is the cause of your ferret's hypoglycemia. Some tests may include:
Blood glucose level. This is the most important test in determining hypoglycemia. Since insulin from the tumor is sporadically released and the blood sugar levels fluctuate, this test may need to be performed several times to get an accurate value and to document hypoglycemia. A short fasting period (3 hours) can help pinpoint the problem.
Plasma biochemistry panel. This test should be run on older ferrets to check for other conditions and to evaluate his general health.
Blood insulin levels. This test is not always reliable.
Surgical treatment. With surgical treatment the affected part of the pancreas is removed. Although this procedure won't cure your ferret, it will give him more time before relapse. Insulinomas usually arise in other areas of the pancreas and because this organ cannot be totally removed, it is likely the insulinoma will return at some point.
Medical treatment. Medical treatment is directed at stabilizing the blood sugar level and keeping it from dropping too low. Two drugs are commonly used for this purpose: prednisone, which raises and stabilizes blood glucose, and diazoxide to lower the insulin levels.
Nutritional management. The goal of dietary management in the ferret is to try to stabilize blood sugar and avoid the "sugar swings" brought on by sweet foods. This is best accomplished by feeding a high-fat, high-protein diet and avoiding sugary supplements like Nutrical® and treats like watermelon or raisins. The good news is that Ferretone® is okay to give.
Chromium supplements. Chromium is thought to help stabilize blood sugar in humans though this has not been proven in ferrets. Brewer's yeast is a natural source of chromium and 1/8 teaspoon can be sprinkled on your ferret's food daily. Even though it has not been shown to be effective in ferrets, it is not toxic and can only help.
Whether or not your ferret is treated surgically or medically, he will still require home care. Proper care will include:
Diet. It is important that you provide proper diet management as described above. If your ferret stops eating for any reason, hand feed or force feed chicken baby food (like Gerber's) or a veterinary formulation like Hill's A/D. You can also provide soaked and blenderized ferret or cat kibble. If your ferret stops eating or changes eating habits abruptly, contact your veterinarian immediately.
Drug therapy. Once diagnosed with insulinoma, your ferret will require medication for life, unless surgery is performed. Even with surgery, some still need medication. Missing even one dose can cause hypoglycemia and missing several doses can be very serious.
Emergency care. If your ferret is weak or is having seizures, seek emergency care as soon as possible. If your pet becomes weak or stuporous and cannot swallow, try rubbing honey or maple syrup on the gums and seek medical help immediately. Do not allow your ferret to have uncontrollable seizures for more than a few minutes.
By understanding the health risks associated with hypoglycemia and insulinoma, you can be better prepared to provide some assistance to your ferret and know when to seek veterinary care.