Please note: I am not a ferret expert, and I did not write, nor did I independently verify, all the information in this file. I have done my best to include only accurate and useful information, but I cannot guarantee that what is contained in this file, whether written by me or by one of the contributors, is correct, or even that following the advice herein won't be harmful to you or your ferret in some way. For advice from an expert, you may wish to consult one of several books available, or, especially in the case of a suspected medical problem, a veterinarian who is familiar with the treatment of ferrets. FERRET MEDICAL FAQ -- INSULINOMA Last modified: 16 Jan 96 Version: 1.4 ------------------------------ Subject: CONTENTS *** Insulinomas, or islet cell tumors *** (1) Islet Cell Tumor in the Ferret (Dr. Williams) (2) Insulinoma (Dr. Brown) (3) Ferret Medical FAQ copyright and redistribution information ------------------------------ Subject: (1) Islet Cell Tumor in the Ferret (Dr. Williams) Written by Dr. Bruce Williams, DVM: The following article may be reprinted by anyone desiring to disseminate this information in a newsletter or non-commercial publication. This material may not be altered or changed in any way. Under Title 17 of the U.S. Code, Section 105, copyright protection is not available for any work of the United States Government. Islet cell tumors, also known as insulinomas, are the most common neoplasm in the ferret, based on the frequency of surgical and autopsy submissions at the Armed Forces Institute of Pathology. Over a period of two and a half years, this neoplasm alone has accounted for almost 15% of all ferret submissions. Islet cell tumors derive their name from their cell of origin. These neoplasms arise in the "islets of Langerhans" - a group of special cells in the pancreas which produce insulin (also giving rise to the term insulinoma). Insulin is a hormone which 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. (In diabetes, the opposite is true - low levels of insulin production render the animal's cells unable to use glucose, and dangerous hyperglycemia results). Not all islet cell tumors appear to be functional, however. Islet cell tumors are often found as incidental findings at autopsy of animals dying of unrelated causes. Finally, a small percentage of animals fail to show characteristic signs of hypoglycemia, or show signs that are so subtle that they are not noticed by the owner and picked up on routine blood screening for other conditions. Hypoglycemic ferrets may exhibit a wide range of clinical signs. Weight loss appears to be a common finding in affected animals, and is occasionally the only sign. This is an excellent reason why you should periodically weigh your pet as part of a good preventive health program. Signs that are more diagnostic of islet cell tumors are episodic depression and lethargy, which in some animals manifests as stupor (apparent loss of touch with its surroundings), salivation, difficulty in using the hind legs, vocalization, and in cases of severe hypoglycemia, seizures. Diagnosis of islet cell tumors is fairly simple and consists primarily of measuring the blood glucose levels in the ferret, which your vet can do if you suspected this problem. (Some vets additionally measure insulin levels, but in most cases, this is unnecessary and wastes valuable time.) Animals with blood glucose levels less than 60 mg/dl should be strongly suspect of having one or more of these tumors. Exploratory surgery in hypoglycemic but otherwise healthy ferrets should be scheduled at the earliest possible time. In animals where surgery is not an option, or until such a time as surgery is possible, medical management may be attempted by using a combination of prednisone (which raises blood glucose levels by mobilizing carbohydrate stores) and diazoxide (Proglycem) an antihypertensive drug which appears to decrease islet cell secretion of insulin. 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.. It is also important to note that in a large number of cases (5/6 in one study), ferrets that had islet cell tumors surgically removed developed a second or more tumors at a later date. (Additionally, make sure that your veterinarian, if surgery is performed, takes a moment to check the adrenal glands for those extremely common proliferative lesions we so often see in ferrets.) If you have a several ferrets, it is extremely likely that one of them, sometime during its life, will develop an islet cell tumor; it's the "nature of the beast". Just watch them closely for the clinical signs that I have described, and have your vet check them if you have even the slightest indication of a problem. Happy ferreting!!! Bruce Williams, DVM williamb@email.afip.osd.mil 1. Marini, RP et al. Functional islet cell tumor in six ferrets. JAVMA 202(3) 430-432, 1993. 2. Kawasaki, TA Personal communication. In a different article, Dr. Williams cautions: The largest number of insulinomas that I have ever seen is four. Ferrets get an age-related finding which is also seen in older cats known as pancreatic acinar hyperplasia. This is a non-neoplastic proliferation of small nodules in the pancreas, which are very normal. The problem is that while this nodular change is perfectly normal and doesn't hurt anything, many vets interpret it as a proliferation of islet cell tumors, and start taking them out. Now the ferret pancreas is fairly forgiving for surgery, but when you take out this many nodules, you stand a good chance of causing a rip-roaring pancreatitis. ------------------------------ Subject: (2) Insulinoma (Dr. Brown) Written by Dr. Susan Brown, DVM: Insulinoma [is] a cancer of the pancreatic beta (insulin producing) cells. It is extremely common in ferrets of her age and the signs are right on. The tumors are very tiny, but produce an excessive amount of insulin which has the effect of driving the blood sugar (glucose) into the bodies cells at too rapid of a rate. Some of the common signs that you might see are: Stopping and staring blankly into space (acting out of it) for a few minutes, then snapping out of it, or foaming and pawing at the mouth as if something is in it (caused by a feeling of nausea....this can also be caused by stomach problems like foreign bodies and ulcers, but those cases are usually not eating well on top of things...insulinoma generally does not interfere with eating habits), or just being weak in the hind end as was described in this case and then coming out of it, or going into a comatose state or even seizures. The more advanced the disease is the more frequent the signs and the more severe. As long as the body is able to it will keep counteracting the low glucose by producing more through the liver primarily...but eventually it will be unable to do so and the ferret may go into a permanent coma and pass away. The disease is easily diagnosed with a FASTING blood sugar test. You need to withhold food for 4 to NO MORE THAN 6 hours prior to the test. This will show if the sugar is too low. Normal fasting sugar should be between 90-120. Your vet can also run an insulin level at the same time, but that is usually (in my experience) unnecessary. Treatment may be a combination of surgery and medical therapy. The worst thing that you can do is give a lot of sugary snacks and treats. All this does is aggravate the condition by stimulating insulin production each time you give them a sugary snack which then results in insulin overload and hypoglycemia later. Use materials such as honey or Karo syrup in small amounts ONLY TO BRING THEM OUT OF A HYPOGLYCEMIC state and then as soon as they are swallowing normally and more alert, give them a protein snack such as strained meat baby food or their softened normal food. The protein keeps the glucose from jumping up and down. It is also helpful to keep food always available and to add a supplement of Brewers Yeast to the diet. You can buy brewers yeast and garlic tablets for pets at health food stores or from you vet if they carry it. Or you can just buy plain Brewer's Yeast in a powder or tablet. Use 1/8 tsp of the powder twice a day, or 1/4 of a human tablet or 1/2 of a pet tablet twice daily. Brewers yeast contains chromium which is the glucose tolerance factor which helps to regulate insulin and glucose levels. These dietary suggestions will not CURE the pet, nor stop the cancer from growing, but they may alleviate some of the signs and prolong the amount of time the pet is off other medication. Susan Brown, D.V.M. ------------------------------ Subject: Ferret Medical FAQ copyright and redistribution information This compilation is copyright 1994-1996 by Pamela L. Greene. It may be freely distributed by electronic, paper, or other means, provided that it is distributed in its entirety, including this notice, and that no fee is charged apart from the actual costs of distribution. (For-profit service providers such as Compuserve and America Online are granted permission to distribute the file provided that no additional fee beyond standard connection-time charges is levied.) Those portions of this file written by others remain the property of their respective authors. 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