This is what I could find about the herbs. Both are believed to helpful
for diabetics. It would seem to me that they would be fighting against
the pred, but I'm not an herbalist. And who knows how the two herbs are
reacting to each other. Note the precautions for both herbs:

http://www.botanical.com/products/learn/d/devils_club.html

http://www.botanical.com/products/learn/g/gymnema.html

I found a website of a shelter that recommends the use of Devils Club.
http://www.newrainbowbridge.com/herbal/devils_club.htm
http://www.newrainbowbridge.com/herbal/DCS_faq.htm

If she is using the Gaia brand Devils Club Supreme then there are other
herbs in it, as well as alcohol as a preservative. It is noted on the
this site that Gaia has discontinued making it.

I hope she discusses this with her vet. If he's basing his decision to
take this ferret off the pred without knowing about the herbs it could
very well be a wrong decision.

Tracy

[Posted in FML 6153]