No-one knows why ferrets get adrenal disease - there are many theories out there; neutered too early (a recent report in JAVMA supports this one), unnatural day/night cycles due to being indoors, a genetic predisposition, manufactured diets vs. homemade/"natural" diets. The adrenal glands seem to first get hyperplastic (overstimulated and enlarge slightly as a result), this can progress to a benign adenomatous enlargement, and finally (in some cases) to a malignant enlargement (ie. carcinoma) - one or both glands can be involved. If only one is involved and it is removed surgically, the ferret may never have another problem (adrenal-wise), or the other adrenal gland may go on to have problems (due to the same unknown reasons that caused the first one to enlarge). The carcinomas (though rarer) can be nasty and usually return at some time "with a vengeance". Some vets remove only the affected adrenal gland, while others prefer to remove all of the largest and half of the other one ("just in case") - there are no wrong answers -if we had a crystal ball and knew down the line that the other gland would have problems, then this may save doing a second surgery, however it may be unnecessary. I personally tend to remove only the affected gland unless both seem enlarged and then I'll remove all of one and half of the other. The question of Lupron vs. surgery - in all the meetings I've attended, it is still recommended that surgery is the best option unless the ferret is not a good surgical candidate (due to age, concurrent illness, etc.). Medical therapies (like Lupron) only help with the signs of the disease - the tumor inside continues to grow. Each method of treatment has it's pros and cons, and you and your vet should discuss these and decide on the best plan for your ferret based on it's individual medical history. On my own ferrets I generally choose surgery. Kate [Posted in FML issue 3074]