Possibilities: There may be a more serious tumor type in the pancreas than an insulinoma. Doing a CBC AND a Chemistry Panel may show enough off to suspect a different tumor. The ferret may have a compromised liver. In that case skip the liver processing step in which the liver processes Prednisone into Prednisolone by instead giving Prednisolone. For some ferrets Prednisone may as well be water for all the effect it has but Prednisolone works great. The dose may be too small. The med may be given too infrequently. The ferret may be so advanced that injected is needed. (In some ferrets it sneaks up and the number you gave is severe.) The ferret may also need diazoxide. Read recent info on insulinoma in places like these: http://www.afip.org/ferrets/PDF/insulinoma.pdf http://www.miamiferret.org/fhc/insulinoma.htm http://ferrethealth.org/archive/SG17063 http://ferrethealth.org/archive/YPG854 http://ferrethealth.org/archive/SG15972 Sukie (not a vet) Current FHL address: http://groups.yahoo.com/group/ferrethealth People can join there or can send a blank mail to the automated joining address: [log in to unmask] and then follow the directions. (The second is recommended for those having problems with Yahoogroups web settings, and afterward send a blank mail from your subscribed address to [log in to unmask] to get the digest instead of individual mails. ) Recommended ferret health links: http://pets.groups.yahoo.com/group/ferrethealth/ http://ferrethealth.org/archive/ http://www.afip.org/ferrets/index.html http://www.miamiferret.org/fhc/ http://www.ferretcongress.org/ http://www.trifl.org/index.shtml [Posted in FML 5492]