12 replies to this topic

[lyok]

Hallo all,

I was wondering how CO₂ works to sedate animals?

I can imagine that the lack of oxygen (or the fact you have more CO₂ in your body than needed) can have an influence , but how exactely does this work?

[mdfenko]

oxygen starvation

[lyok]

oxygen starvation

Ok, but thats pretty straight forward.
But whats the effect then? How come you get sedated? its just because of the lack of oxygen? And how come the animals dont die? Its just because you remove the CO₂ fast enough or?

[mdfenko]

it will kill the animal. one of my neighbors used to use co2 to sacrifice his animals so that there would be no drug induced alterations to the brain.

the animal pants then falls asleep. if you don't take it from the co2 chamber, it will die.

[pcrman]

No, CO2 cannot be used to sedate animal, is used to euthanize animals and can cause pain and stress before they die. Take a look here http://www.slideshar...thanasia-357399

[hobglobin]

No, CO2 cannot be used to sedate animal, is used to euthanize animals and can cause pain and stress before they die. Take a look here http://www.slideshar...thanasia-357399

for arthropods CO₂ works quite well for sedation and is used commonly...but they have a quite different physiology and less complex nervous system...So for some animals it is usable...

[Fungus_Dreams]

Hallo all,

I was wondering how CO₂ works to sedate animals?

I can imagine that the lack of oxygen (or the fact you have more CO₂ in your body than needed) can have an influence , but how exactely does this work?

CO2 in inhaled and replaces oxygen in the bloodstream, resulting in loss of consciousness.

Here's my question: are you intending to revive these animals? In which case you need isoflurane....

[lyok]

No, CO2 cannot be used to sedate animal, is used to euthanize animals and can cause pain and stress before they die. Take a look here http://www.slideshar...thanasia-357399

Yes and know: I did read some papers where they stated that CO2 sedation for pigs (castration) is a pretty good option...

for arthropods CO₂ works quite well for sedation and is used commonly...but they have a quite different physiology and less complex nervous system...So for some animals it is usable...

Can you give some more details about this? How come its better/ok for insects (or arthropods in general).

CO2 in inhaled and replaces oxygen in the bloodstream, resulting in loss of consciousness.

Here's my question: are you intending to revive these animals? In which case you need isoflurane....

Eum, we used it on arthropods, but also on mice.. and I didnt really use isoflurane to revive the mice.. But to be honest: we only "sedated" them a bit to handle them a bit easier...

[leelee]

Eum, we used it on arthropods, but also on mice.. and I didnt really use isoflurane to revive the mice.. But to be honest: we only "sedated" them a bit to handle them a bit easier...

You have ethics approval to use CO2 as a sedative for mice, to aid with handling them?

[lyok]

Eum, we used it on arthropods, but also on mice.. and I didnt really use isoflurane to revive the mice.. But to be honest: we only "sedated" them a bit to handle them a bit easier...

You have ethics approval to use CO2 as a sedative for mice, to aid with handling them?

Well for the arthropods: I am 100% sure its CO₂
But for the mice: I am not sure (I dont really work with them, I did it once and I just assumed they used CO₂ too.)

[Tabaluga]

Interesting discussion. In our lab the mice to be killed are put into a CO2 chamber. Then they get convulsions and you can observe a really heavy breathing. They are then taken out and killed by breaking the neck. I always wondered at which point they are dead ? At the moment of breaking the neck or already before ? Can someone tell me ?

For sedation they get something injected, but I don't know what.

[bob1]

Sedation of mice is usually done with ketamine. CO2 is not a good option as it has a very high risk of death if you get the dose wrong, and when you switch it off, the mice will revive very quickly if they aren't dead.

@Tabaluga, the CO2 should kill them if they are left there for long enough. THe trick with CO2 is to increase the level slowly so that the mice go to sleep before dying. If you increase too quickly, the mice will convulse, bleed from the nose and pant really heavily. Breathing in high concentrations of CO2 is very painful too (If you want to try this for yourself get someone to watch you first of all, then put some dry ice into a sink or bucket, leave for a while and then olwer your nose just below the lip of the bucket and inhale).

[Jesper Andersen]

We did a short study at Life in copenhagen, to determine the stress induced by CO2 sedation and ketamine sedation, by measuring cortisol buildups over an extended time. No significant difference where detected the two groups inbetween, but compared to the controls, both had elevated cortisol levels. (based on ELISA). Regardless of the method, forcing a mammals body to act against it's natural state, will stress the animal. A downside with using CO2 is, as more have already stated, that done by unskilled personel, deaths may occure due to overexposure or shock.

Edited by Jesper Andersen, 30 September 2013 - 11:41 PM.