I'm sorry your ferret has been diagnosed with cancer. The pred usually will help and can give days, weeks, or months depending on the type of cancer and how far it has spread already, and of course the rate of spread. I am not sure that your ferret has "lung cancer" per se....it is more likely lymphoma which has shown up in the lungs, which I guess is still lung cancer but not in the way we think of in people. But, that is a question to ask the vet - is it lung cancer, or lymphoma? From my personal experiences with 2 ferrets who showed spots in their lungs, it was the first visible sign of lymphoma. Upon their death, it was found to be long present in the other organs. Still, some ferrets live a long time after being diagnosed once put on Prednisilone. I hope that is your fuzzies case! Laryssa [Posted in FML 6597]