Best way to pre-kill?

[Mephibosheth1]

Mice/rats are different than people in their gas sensing abilities. They do not react to a buildup of CO2, but to a lack of oxygen. That is why slowly cranking up the gas makes them freak out; they can feel the oxygen level decreasing, so they try and run.

People on the other hand are wired to detect CO2 levels. We begin to "freak out" when the CO3 levels are too high, not when the oxygen levels drop.

Moral of the story: slowly turning the gas up is actually more traumatic for the rodent than it may appear. The BEST way to administer the gas (and this is from actual experience with research animals, who MUST be killed 100% humanely) is to pre charge the container with CO2, then drop the mouse in. That way it goes from pure room air to pure CO2 instantly...thy are unconscious before they even hit the bottom of the container. The gasping breaths they take are stimulated by the brainstem AFTER they are unconscious; thus they are not feeling pain or suffering in any way.

[MrLang]

if you use gas, i would advise against the use of CO2.

its rather quick, but when mammals detect a CO2 increase in the blood stream they react with panic and a feeling of asphyxiation before they die.

i think its more humane to use a gas that prevent such a CO2 buildup.

nitrogen or helium is much slower, but since there is no CO2 buildup they fall asleep peacefully.

optimal would be nitrous oxide / laughing gas. super fast and super painless, it knocks them out within a few seconds and they feel euphoria. you can cheaply buy single-use cartridges that are usually used in whipped cream dispensers. its legal to own as long as you dont use it as a drug.

edit @ tribal: i think its the mass murderer clown from the Rob Zombie movie "house of 1000 corpses"

You have to stop this. There is enough misinformation floating around in this hobby - please stop deliberately contributing to it. Science proves this wrong - we've shown you the studies and the outlines written by organizations who don't huff gas but rather measure brain waves to determine how traumatic death is. Cervical Dislocation and CO2 are the only methods approved as humane. Depending on where you live improperly euthanizing an animal is illegal.

The forum guidelines on BP.net very clearly state that no member can wittingly post information that advises another member to break the law. As such, PLEASE stop making this post. I wish we had a 'science mod' that went through threads and deleted posts that contradict proven science or spread misinformation in the face of fact.




It's Captain Spaulding in the picture. I was him for halloween a few years ago - shaved head, beard, face paint, the whole nine. I was at a party that got busted by the cops and the cop started messing with me in a somewhat friendly way (cops in Boston have to break up Halloween parties when there's a complaint but they're not completely unreasonable about it). I responded with "DON'T YA LIKE CLOWNS? AREN'T WE BLEEPIN FUNNY?" - a quote from the movie. He didn't so much enjoy my back talk and I almost got put in cuffs...

[satomi325]

if you use gas, i would advise against the use of CO2.

its rather quick, but when mammals detect a CO2 increase in the blood stream they react with panic and a feeling of asphyxiation before they die.

i think its more humane to use a gas that prevent such a CO2 buildup.

nitrogen or helium is much slower, but since there is no CO2 buildup they fall asleep peacefully.

optimal would be nitrous oxide / laughing gas. super fast and super painless, it knocks them out within a few seconds and they feel euphoria. you can cheaply buy single-use cartridges that are usually used in whipped cream dispensers. its legal to own as long as you dont use it as a drug.

edit @ tribal: i think its the mass murderer clown from the Rob Zombie movie "house of 1000 corpses"

Well..... at least you're not spouting off about using noble gases anymore.....
But seriously, did you not read any of the papers I linked to you the dozen other times you said C02 was the worst method of euthanasia?


If not, here they are again from that response.

Nitrogen, argon(a noble gas), and CO may be acceptable for euthanasia, but according to the University of Texas, "there is no clear advantages, which is why they are rarely if ever used."

If they and the other gases you listed were more effective and humane, then CO2 wouldn't be the standard gas of choice for euthanasia.
I work in a laboratory at one of the top research universities, not to mention the number one veterinary school in the US. I have euthanized a vast amount of rodents in the lab and at home with my own personal feeder colony. I have seen and done this first hand. CO2 is humane if administered correctly. Please refer to the IACUC and AVMA protocols for responsible euthanasia use. CO2 isn't used based on 'tradition'. CO2 isn't used just because it is fast. Euthanasia doesn't mean fast. Euthanasia is the act of inducing humane death in an animal by a method that induces rapid loss of consciousness and death with a minimum of pain, discomfort or distress..... It's used because it has been proven as humane method of euthanasia. (Equal or more so than other gases. However, they can be used in combination with CO2.)

Some studies that show adverse effects of Nitrogen/Argon euthanasia:

I. Joanna Makowska, Lee Niel, Richard D. Kirkden, Daniel M. Weary, Rats show aversion to argon-induced hypoxia, Applied Animal Behaviour Science, Volume 114, Issues 3–4, 1 December 2008, Pages 572-581, ISSN 0168-1591, 10.1016/j.applanim.2008.04.005.



Burkholder TH, Niel L, Weed JL, Brinster LR, Bacher JD, Foltz CJ. 2010. Comparison of carbon dioxide and argon euthanasia: effects on behavior, heart rate, and respiratory lesions in rats. J Am Assoc Lab Anim Sci 49:448–453.


(MAP, mean arterial blood pressure)
According to the Journal of the American Association for Laboratory Animal Science, Volume 45, Number 2, March 2006 , pp. 21-25(5), they say that CO2 is effective for inducing unconsciousness and euthanasia. Ar appeared to be effective, but produced hyperflexia and tachycardia effects. They also concluded that N2 is not satisfactory for euthanizing rats or inducing unconsciousness in them.


Studies that show CO2 with no adverse effects:

Smith W, Harrap SB. 1997. Behavioural and cardiovascular responses of rats to euthanasia using carbon dioxide gas. Lab Anim 31:337–346. [PubMed]



Hackbarth H., Küppers N., Bohnet W. (2000). Euthanasia of rats with carbon dioxide – animal welfare aspects. Lab. Anim. 34, 91–96. doi: 10.1258/002367700780578055. [PubMed]


And another note, I've inhaled nitrous oxide for an oral surgery. It's probably a personal thing, but it did nothing for me. :\

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[vankmen.]

It's jack Nicholson from the shining " here's Johnny "

[Badgemash]

I'm going to cut and paste my post from the DIY forum, since I appear to be the only one here who's actually had intentionally induced hypoxia in a controlled environment and knows what it feels like to have CO2 build up in my blood...



I'm going to skip over all the debate and add in a minor detail that I think may be relevant as far as CO2 goes. As military aircrew you have to do altitude chamber training regularly, most depressurization events are slow leaks (the kind you see in the movies is super rare) so it is essential to know (and be reminded at regular intervals) what hypoxia actually feels like so you can recognize it and respond appropriately. I'm assuming not many people have here have first-hand knowledge of what it feels like to actually be hypoxic.

Losing oxygen fast (we did practice that too) is pretty scary, you can feel your lungs straining and it is alarming. Slow leaks however are kind of fun. Everything in your brain slows down, things seem amusing for no reason. Your reactions slow dramatically, but it isn't alarming, more of an intriguing event that you somehow can't process. Eventually the fog gets thicker and thicker and you black out (or put your ox mask on and suddenly realize you were seeing in black and white only and didn't even notice).

I have no reason to think that rodents experience hypoxia any differently than humans, we're mammals with very similar biological processes. Thus I believe that CO2 is a humane method as long as it is done gradually. Just control the flow, however you chose to do it.

[satomi325]

I'm going to cut and paste my post from the DIY forum, since I appear to be the only one here who's actually had intentionally induced hypoxia in a controlled environment and knows what it feels like to have CO2 build up in my blood...



I'm going to skip over all the debate and add in a minor detail that I think may be relevant as far as CO2 goes. As military aircrew you have to do altitude chamber training regularly, most depressurization events are slow leaks (the kind you see in the movies is super rare) so it is essential to know (and be reminded at regular intervals) what hypoxia actually feels like so you can recognize it and respond appropriately. I'm assuming not many people have here have first-hand knowledge of what it feels like to actually be hypoxic.

Losing oxygen fast (we did practice that too) is pretty scary, you can feel your lungs straining and it is alarming. Slow leaks however are kind of fun. Everything in your brain slows down, things seem amusing for no reason. Your reactions slow dramatically, but it isn't alarming, more of an intriguing event that you somehow can't process. Eventually the fog gets thicker and thicker and you black out (or put your ox mask on and suddenly realize you were seeing in black and white only and didn't even notice).

I have no reason to think that rodents experience hypoxia any differently than humans, we're mammals with very similar biological processes. Thus I believe that CO2 is a humane method as long as it is done gradually. Just control the flow, however you chose to do it.

I agree with you and you are 100% correct. And disagree with Mephibosheth1.
The most humane Co2 administration is to go slow. Once they pass out, do a rapid release to euthanize.
Pre-charged or quick release of Co2 from the start is inhumane and causes the animals to panic/stress more. Suffocation while conscious is painful. Suffocation while unconscious is not.

[Badgemash]

I agree with you and you are 100% correct. And disagree with Mephibosheth1.
The most humane Co2 administration is to go slow. Once they pass out, do a rapid release to euthanize.
Pre-charged or quick release of Co2 from the start is inhumane and causes the animals to panic/stress more. Suffocation while conscious is painful. Suffocation while unconscious is not.

This is why slow pressurization leaks at altitude are so insidious, stuff like this happens http://en.wikipedia.org/wiki/Helios_Airways_Flight_522 and you never even realize that something's wrong as you're suffocating. Honestly, having experienced hypoxia, it would be my death of choice if I had an option. You actually feel little bursts of happiness. My friends actually have several photos of me at Mauna Kea Observatory plopped on the ground smiling to myself (and possibly video of me trying to sing Janis Joplin to a soda bottle on the way back down).

[Pythonfriend]

death by CO2 has nothing to do with death by loss of oxygen.

its true, mammals cannot detect a drop in blood oxygen levels or atmospheric oxygen levels, mammals dont really know whats going on and then they pass out.

BUT MAMMALS ARE AWARE OF BLOOD CO2 LEVELS AND FREAK OUT COMPLETELY WHEN A RISE IN BLOOD CO2 IS DETECTED.

thats like suffocating in a room without fresh air. its also half of the reason why drowning is so terrible. you do feel that the air is getting bad, unbreathable, you get terrified, and suffocate in agony. that is all the response to blood CO2 level increase. its sneaky and undetectible only when you have a drop in blood oxygen levels WITHOUT corresponding CO2 buildup, like when a pressurized cabin leaks or on mount everest.

with CO2, its not like getting drowsy at low pressure or high altitude. you can have that for your rhodents if you use a noble gas or nitrogen. you cannot have that when CO2 is used. if you want to grant mammals a peaceful death by an undetectible drop in oxygen so that they peaceful pass out, you can use basically anything other than CO2 to displace the oxygen. hydrogen, nitrogen, helium, argon, whatever.

just inhale some CO2 already and tell me it feels just like one of these military pressure drop experiments, i dare you. the fact is it doesnt. you get that light-headedness drowsyness without fear and panic if you overdo it with breathing helium for funny voices. CO2 is totally different and just dreadful.

[MootWorm]

This is why slow pressurization leaks at altitude are so insidious, stuff like this happens http://en.wikipedia.org/wiki/Helios_Airways_Flight_522 and you never even realize that something's wrong as you're suffocating. Honestly, having experienced hypoxia, it would be my death of choice if I had an option. You actually feel little bursts of happiness. My friends actually have several photos of me at Mauna Kea Observatory plopped on the ground smiling to myself (and possibly video of me trying to sing Janis Joplin to a soda bottle on the way back down).

Quite interesting! Thanks for sharing. Although I think we need to see this video to fully appreciate the effects of hypoxia...

[satomi325]

death by CO2 has nothing to do with death by loss of oxygen.

its true, mammals cannot detect a drop in blood oxygen levels or atmospheric oxygen levels, mammals dont really know whats going on and then they pass out.

BUT MAMMALS ARE AWARE OF BLOOD CO2 LEVELS AND FREAK OUT COMPLETELY WHEN A RISE IN BLOOD CO2 IS DETECTED.

thats like suffocating in a room without fresh air. its also half of the reason why drowning is so terrible. you do feel that the air is getting bad, unbreathable, you get terrified, and suffocate in agony. that is all the response to blood CO2 level increase. its sneaky and undetectible only when you have a drop in blood oxygen levels WITHOUT corresponding CO2 buildup, like when a pressurized cabin leaks or on mount everest.

with CO2, its not like getting drowsy at low pressure or high altitude. you can have that for your rhodents if you use a noble gas or nitrogen. you cannot have that when CO2 is used. if you want to grant mammals a peaceful death by an undetectible drop in oxygen so that they peaceful pass out, you can use basically anything other than CO2 to displace the oxygen. hydrogen, nitrogen, helium, argon, whatever.

just inhale some CO2 already and tell me it feels just like one of these military pressure drop experiments, i dare you. the fact is it doesnt. you get that light-headedness drowsyness without fear and panic if you overdo it with breathing helium for funny voices. CO2 is totally different and just dreadful.

Refer to post #23.
When you are able to post scientific proof that counters my scientific proof, maybe I'll take your posts seriously. You keep saying use nitrogen or a noble gas over and over and over again like a broken record countless times for the past year. Well, I cited credible scientific sources that say Nitrogen and Argon are poor substitutes for Co2. In fact, it could be rather adverse to the animals.

Refer to post #23.Refer to post #23.Refer to post #23.Refer to post #23.Refer to post #23.Refer to post #23.Refer to post #23.