Imuran (Azathiaprine), which is a drug that is used to prevent rejection of organs from donors, can be used to treat IBD. When dosed correctly for ferrets, Imuran is more effective and has fewer side effects than prednisone/prednisolone. It's supposed to be safer than pred., especially when used on a long term basis.
As with and medication that suppresses the degree of immune response, Imuran will lower immunity to infection/disease just as pred. will. However, the risk associeted with Imuran does not seem to be dramatic as imuran is gaining acceptance for use on IBD ferrets. Here is a link on the AFA website to an article by Dr. Mark Burgess that discusses IBD, including Imuran dosing:
I will also post another thread that dicusses ferret G issues, including IBD. This second article is also by Burgess - it's very informative with treatment information as well. Look for the thread called "Burgess on Ferret G.I. issues"
Boris did well with Imuran for a short period of time. However given he ultimately refuse any meats with supplements it didn't wind up helping any more than pred
Ferrets: Contessa Kitties: Watson, Oskar DIP Sinnead, Vincent, Boris, Zeus and Athena, Willow, Mr. Frodo, Indie, Lucrezia, Judge, Odin, Miss Emily, Suki, Cody, Aristotle, Butterscotch, Frankenfurter. RIP Herne, Ligeia, and Mr. Stubbs