A ferret will come to no harm at all if fed on mixy rabbits, but I dont feed mine them.
I hate the desiese, and (touch wood) it seams to be getting less damaging to the rabbits in my area. So now I bury any mixy rabbits I get straight away.
As we all know that it is spread by the fleas, which will be jumping off the dead infected rabbit on your travels, and possibly spreading the desease to other areas.
Its just what I now do, feck knows if it actually does help any, but hey, im never short of clean, healthy rabbits so im happy!