Ferrets are not particularly prone to tumours, either benign or malignant, but when they do present with cancer, it is very likely to be an insulinoma, also known as pancreatic islet cell tumours, which describes them rather more precisely. In a nutshell, insulin, vital for the metabolism of glucose, is produced in the islets of Langerhans, small clusters of cells in the pancreas. If these cells divide out of control, they produce far too much insulin, which places the ferret in a hypoglycaemic state as too much glucose leaves the bloodstream. It is this hypoglycaemia which causes the symptoms which the ferret will display. The one good thing to say about insulinoma is that in a properly looked after ferret, where the owner is aware of its normal behaviour and monitors it constantly, this disease is not a sudden killer. The onset is insidious, so may be missed in the very early stages, but it is unlikely that the first hypoglycaemic episode will be profound enough to be fatal.
What to watch out for
Insulinomas tend to occur in middle aged ferrets, those between four and six years old. For the ferret, this is unhelpful, as the animal may be slowing down anyway, due to being a bit older, and so the early signs of the disease may well be missed. The first positive symptom may well be that the ferret is unresponsive and may even collapse briefly. This is usually enough to trigger a visit to the vet, when a fasting blood sugar or glucose tolerance test will soon give a positive diagnosis. The ferret may also show weakness in the legs or may have a seizure. Before all this happens, it may drink a lot more, or drool and paw at its mouth. Many owners mistake this for mouth problems and if this is the only symptom which is seen, it can delay diagnosis. There may also be weight loss, or changes in appetite, but these signs do not occur in all cases.
Treatment of tumours of the pancreatic islet cells
There is no total cure for insulinoma. Surgery can certainly help alleviate the condition by removing the larger tumours, but it is impossible to remove them all, as some cells groups which appear to be normal are in fact already cancerous and will grow after the surgical procedure is complete. However, removing the majority will turn back the clock on the disease process and if the ferret is otherwise well, it can gain a reasonable quality of life for quite a while, even up to a ferret’s normal life span of around eight years, depending on its age at the onset of the disease. Unfortunately, insulinoma is not always found as a single condition, but may be linked to general endocrine problems and the vet often finds while doing the surgery that there is also a malignancy associated with the adrenal glands. When the surgery is completed, or if it is not recommended because of the age of the animal, it is possible to slow the progress of the disease with prednisone or a similar medication.
Managing your ferret after diagnosis
After diagnosis of insulinoma, and following surgery if appropriate, your ferret will need quite a lot of care. Much of this will depend on dietary changes, so if the ferret has been used to eating with companions, this may have to be looked at as a lifestyle, because it is hard to control the diet of just one in a group. Food must always be available as the ferret will naturally balance its glucose balance if given the chance. The food provided must be a good quality meat based ferret food – the proprietary brands from reputable sources are high in protein and low in carbohydrates, which is an ideal ‘diabetic’ diet. To save overloading the animal’s system, sweet treats are absolutely and strictly forbidden. A rush of glucose will stimulate the tumours to produce insulin which will inevitably result in a hypoglycaemic episode.
Ferret first aid
Before you take your ferret home after a diagnosis of insulinoma, you must make sure that your vet gives you adequate training on how to cope with a hypoglycaemic episode. Just as in the case of a diabetic human in a hypo, you need to administer glucose – the insulin has driven the glucose from the bloodstream and the aim is to replace it. This can be done with any glucose syrup, so keep some handy, but don’t do it without having had the training. The amount to give is vitally important and you may do more harm than good if you do it wrong. Also, the ferret may feel cold during a hypoglycaemic episode. This is normal, so keep it warm and calm. If the ferret lapses further into a coma and becomes completely unresponsive, take it to the vet as soon as possible, although if this turns out to be a further progression of the condition, there may be nothing which can be done.
Time to call time
Insulinomas are not painful, but your ferret will not be feeling on top form and may sometimes feel very wretched indeed. Balance your love for the animal against its age, any other underlying conditions and how it may be feeling. It may be that it is time to let your pet die in peace – a ferret post surgery can live for between six months to a couple of years, but if the medication and frequent hypos are stressing you both out, euthanasia may be the kindest option.