A recent FHL member had lost some ferret suddenly and wondered if melatonin could have been the cause. It simply doesn't fit at all, though. It IS possible that the melatonin had over the counter medications added since one member did encounter just such a brand and we all know that a number of human OTCs are dangerous for ferrets. Also possible is that the bottle had been tampered with or had a manufacturing error. Finally, it is possible that there was nothing even remotely related to the melatonin involved, such as pre-existing medical condition, or the ferrets getting into something the person did not realize they got into. As the saying goes, "Ferret proofing is never done." Mike Janke's bibliography: http://www.smartgroups.com/message/readmessage.cfm? gid=1423922&messageid=11663&startid=11672 http://www.smartgroups.com/message/readmessage.cfm? gid=1423922&messageid=11683&startid=11692 I am so sorry that this happened to your ferrets - however, I think Sukie nailed this one on the head. It is incredibly unlikely for this to have been due to the melatonin itself. There has to have been something wrong either with the manufacturing and purification process (which sadly, does happen) or with that particular bottle having been adulterated. Or, potentially, that there was something else that the ferrets got into without your knowledge. Melatonin in and of itself is very, very safe. Dr. Ruth ******************************************** Puppies kiss better than most people. http://www.smartgroups.com/message/readmessage.cfm? gid=1423922&messageid=11711&startid=11712 Sorry to hear that you lost your ferrets, but your description certainly does not sound like the cause of death was from melatonin. In the one description of a post surgery ferret having projectile vomiting then sudden death, I would suspect a gastric (stomach) ulcer that hit a blood vessel (thus the blood in the vomitus) as it perforated. Melatonin has been used in research projects for 3 decades in ferrets (both orally and by injection), and for 20+ years in mink. When I contacted one of the melatonin implant researchers (Dr Bruce Murphy, University of Montreal), one of the things he pointed out was "the lack of toxicity." There was no adverse reactions in the ferret study or in several mink studies. In the mink toxicity study they gave an average dose of 124 mg/kg to 8-10 week old female mink kits. No adverse reactions, no signs of toxicity, no gross or histopathologic changes. The kits did gain more weight than the control group. You can get those studies from the FDA's website. There have also been a lot of melatonin research in humans, again with no toxicity. One human study even said melatonin had a "complete lack of toxicity" (Modulation of cancer endocrine therapy by melatonin: a phase II study of tamoxifen plus melatonin in metastatic breast cancer patients progressing under tamoxifen alone, Lissoni P, et al, British journal of cancer, vol. 71, 1995, p 856). Again sorry about your loss, Jerry Murray, DVM [Posted in FML issue 4715]