[Sukie note: If carbon monoxide is the culprit here then I have heard of about a half dozen cases in which ferrets died before the people knew something was wrong. Their deaths saved the others in those cases but a carbon monoxide detector would have gone a long way to prevent any deaths. I think that perhaps many people don't know that there are incredibly affordable CO detectors.] http://www.smartgroups.com/message/readmessage.cfm?gid=1423922&messageid=3056 >this situation happened overnight at one of our foster homes. the home >is older with a gas furnace (not sure which type of gas yet) and they've >definitely had uneven heating; thus the window in the ferrets room is >always cracked. Carbon monoxide probably is the most likely possibility here - especially if the gas heater is older - they can often vent combustion gases, of which CO is one. It can be a very difficult thing to prove if the necropsy is delayed. At necropsy, the blood and organs are a bright cherry red color, but this dissipates fairly quickly. With kindest regards, Bruce Williams, DVM [Posted in FML issue 4033]