>His BG at the vets was 40 or 41 and he had not eaten... Leslie

When a ferret is adrenal, the tumors can put out excess adrenal
hormones. The adrenal hormones can raise blood sugar, thus mask
Insulinomas. Perhaps the implant calmed the adrenal tumors thus
lowing the hormones they were pumping out & the insulinmoma reared
it's ugly head. Just a guess on the blood sugar part of the reaction.

Tracy

[Posted in FML 7090]