Help! Does anybody know how to immunosuppress a rabbit? Urgent!

[Tim C. Frandsen]

I was wondering if anybody can tell me the best way to suppress a rabbit's 
immune system.  I know that rabbits are very sensitive to changes in 
intestinal flora, which is a serious concern.  If anybody has any information, 
I would greatly appreciate it.  Ultimately, I need to know what drug is most 
affective, and at what dose.  Please e-mail me or post a reply.  Thanks!