Well, as those who listened to Dr. Karen's talk at the 2008 IFC Symposium know there is mink spongiform encephalopathy which is the form of prion disease that has been seen in ferrets if fed those mink neural tissues but I doubt anyone here is feeding minks to their ferrets. There are a number of different prion diseases. Not all cross specific species barriers, and some can cross barriers only if there are certain specific intermediate hosts. None of the attending vets challenged that the other prion diseases aren't really a concern. I would not let the hype worry you, but instead learn more on the topic first. There is vegetable derived melatonin, but animal sources are not the only other alternative. Much melatonin sold is created to simulate natural mammalian melatonin rather than being from cattle. So, there is artificial melatonin for many uses. Not being from vegetable sources does not automatically mean melatonin is from animal sources any longer. Neither CDC nor the World Health Organization list any hazard that I can find when I searched. All that I could find from anywhere that could possibly be trustworthy were these (See the YEAR on each.) http://www.vrp.com/deardoctorresults.aspx?ProdID=deard563&zTYPE=3 http://www.merck.com/mmpe/sec22/ch331/ch331t.html and no definite risk is mentioned anywhere reputable that I could find. I DID also check PubMed and found no abstracts on my search that mentioned melatonin supplements as a source of any prion disease. There were some OLD "this should be looked into" things but notice that nothing came from them and that any such hazards would have been well announced if they had been. There were also a load of total hype things out there on the internet, ones that basically have the validity of the rumor mill. Also, notice that although there is a dearth of regulation for some aspects of "health food store" type products that the FDA DOES pull and ban products which have proven to have hazards. If you go to http://www.fda.gov/opacom/7alerts.html and search or even just scroll you will find a number of such items. Sukie (not a vet) Recommended ferret health links: http://pets.groups.yahoo.com/group/ferrethealth/ http://ferrethealth.org/archive/ http://www.afip.org/ferrets/index.html http://www.miamiferret.org/fhc/ http://www.ferretcongress.org/ http://www.trifl.org/index.shtml http://homepage.mac.com/sukie/sukiesferretlinks.html [Posted in FML 6220]