zinfamous
No Lifer
CO2 really? That causes the sensation of suffocation. Nitrogen is equally lethal and does not cause the body to feel like it's in distress. Helium, Argon, or Nitrous Oxide would also work. Interesting that a government mandate on humane treatment would force inhumane treatment. Well... less humane than it could be. Then again, duck, duck GOOSE!
yes, it's completely backwards. IACUC is the mandating body that enforces these policy. For the longest time--cervical dislocation or even decapitation were generally regarded as the most humane methods. Then, for whatever reason, a general consensus emerged that the seeming violence of these methods were in themselves considered inhumane, and the CO2 method became the norm.
Actually, much like what bfdd was implying, this is more a policy of transferring the emotions and comfort of the researcher into that of the animal--CO2 is less messy for the person--you shove them in a tub and pump in CO2, the person doesn't have to get their hands dirty.
Of course, IACUC doesn't sit around and actually do any of this--Perhaps if they spent their days watching mice and rats claw and tear at each other as they scramble to escape their death chambers, they might think twice.
If you have several tubs of mice that need to go down, you have to hide the others from view of those that are being pumped CO2--it is visually distressful to the mice to watch the other mice drown. I have first-hand experience with this, which is why I think guys like bfdd don't really know what they're talking about when they seem to assume what animals feel and what they think--all it takes is a little exposure to start to understand.