Dear Pam:
 
>SO my questions are: Has anyone ever had an insulinomic ferret become
>diabetic from pred and/or diazoxide?  And if so, did you get things back
>to normal by cutting back or stopping either one?  Did anyone need to
>start giving insulin?  Are there other things besides a weird reaction to
>the meds that can be causing this (glucagonoma was something my vet found
>mentioned as a possibility while she was doing some research but I haven't
>heard anything about that before)?  Searching the archives showed a few
>similar cases in the past but not all have followup and results seem mixed.
>Seems like it can be hard to regulate these guys very well...
 
Pam - this is an odd case.  I've seen a number of ferrets become diabetic
after surgery, but I think this is the first time I have seen a
medically-treated ferret go diabetic.  In some ferrets with insulinoma, the
persistently high levels of insulin secreted by the tumor result in atrophy
of the other, normal pancreatic cells which secrete insulin (the body has
lots of these feedback mechanisms.) If the body senses an adequate or
elevated level of insulin, it shuts down normal production.  But in this
case, it would appear that the tumor has stopped secreting insulin as well,
which is very odd.
 
I have had a number of supposed glucagonomas submitted, but none have ever
been true glucagonomas.  Glucagon is the hormone that is the opposite of
insulin, and it is also secreted by the islet cells of the pancreas.
Whereas insulin results in lower blood glucose, entry of glucose into the
cells of the body; glucagon causes an elevation of blood sugar, resistance
of cells to entry of glucose, and increased production of glucose in the
liver.  A glucagonoma is an "anti-insulinoma" But I've never seen one in
a ferret - yet.
 
I think at this point, we need to quickly scale back and eventually quit
the pred and diazoxide, and if the blood sugar is as high as you are
mentioning - it is likely that insulin is going to be required in this
case.  We sometimes can manage animals in the high 100's and low 200's by
diet, but not in the 3-500's.
 
With kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3259]