>While almost all mast cell tumors are benign, but not every growth that >looks like a mast cell tumor actually is. Very good point, Kara. It's yet one more example illustrating why those thinking of skipping treatment and pathology should know that route is not a good idea. Oh, another thing to not skip: if a ferret dies of unknown cause then be sure to get a necropsy with pathology. I was glad to day to see someone following that logical step. Finding the cause of the death has multiple times for FML members led to finding a disease cause that could then be tackled, thus saving other ferrets. Twice now, I think, if memory serves, it has led to finding a cause which also would have become dangerous to other family members, including the humans. Pathology work by a ferret knowledgeable veterinary pathologist is extremely useful; don't go for shortcuts. Sevie update: in a few days she will have gone 5 months despite having a complete A/V Heart Node Block that entire time. This is a situation in which the electrical communication and synchrony between the heart chambers is lost and in humans it leads to an emergency pacemaker placement. Sev wasn't a pacemaker candidate for other medical reasons, but for those who want to know there are new types of pacemakers that are small enough for female ferrets. She is on medical treatment, and this has been harder since she began having complications about a month or so ago, but except when she is getting her meds and despite being terminally ill and able to die any time she's a happy girl -- still playing and still kissing -- despite having been expected to survive mere days early on. A/V Heart Node Block is an extremely rare complication of insulinoma so it is still something about which we are all learning in relation to ferrets. Advanced insulinoma: two things that your vet may want to have consultations on: Prednisone levels are now thought to be individual-dependent so if the ferret copes with higher levels then those are possible. (Watch out for ulcers, and know that some illnesses preclude or limit the amount of Pred that can be used.) Dr. Karen Purcell is among the folks your vet can speak with on that regard. The other is Dr. Bruce Williams who has reported that the insulinoma tumors themselves are not responsive to blood sugar levels so in advanced insulinoma using dietary sugar won't have bad results. As a result of these pieces of info when elderly Warpie's insulinoma got advanced she had higher levels of Pred than are found in the texts, and dietary sugar was added to her intake. The result was that she comfortably went months more and had a good time for almost all of that added time beyond when the older standard approaches failed to work. In fact, her insulinoma remained under control and what finally took her was her lymphoma. Hope this helps. [Posted in FML issue 3968]