CO₂, I know people that just put them in the freezer, but I think that's an awful way to go.  I highly recommend investing in the CO₂ because then if you ever decide to raise mice you'll have it on hand.

Ok Ive heard co2 before can u tell me how to use it?

http://www.youtube.com/watch?v=M1mIBYj5q8w

There's a link in the description where you can buy one, I haven't had a chance to register for that site though.  Hope this helps.

There are a number of humane ways to achieve this. The most hands-off approach is to place them in a container and subject them to CO₂ gas. Granted, this may be a bit too involved if these eight mice are the only ones that you will ever have to euthanize. Another option is to use cervical dislocation, which is very fast and effective. It involves using a rigid object to push down on their neck, then pull the tail away from the head. If performed correctly, it separates the vertebral column and spine from the head, instantly killing the animal. The disadvantage to this method is that it sometimes takes people a couple of attempts before they overcome the learning curve.

+1 to NF99...and please DON'T just stick them in the freezer, it's terribly cruel.

if you don't want a CO2 canister, you can still make a one-time gas chamber by putting them in a sealed container (not tightly sealed, maybe a little teeny gap at the top) and toss in a big chunk of dry ice.  the best container is a styrofoam cooler/shipping box, IMO, because they don't make an airtight seal. dry ice expands as it evaporates and an airtight container could explode. 

whatever you use, you'll want to toss it in the garbage and not re-use it. they'll give off fear pheromones, among others, when they die - stinky, stinky

Grab them by the tail and put your fingers behind there heads Give a good tug  and break there necks

I used the dry ice to kill some rats it work well and is fairly cheep.

i use cervical dislocation. I want to get a C02 chamber eventually though.

I raise rats and mice for food. I use cervical dislocation. But am making my own co2 chamber.

a note about the co2.... it is only humane when it is very slowly released into their environment. to fast and it suffocates them, causing them to hyperventilate and twitch a lot as they die...  cervical dislocation may result in twtiching and kicking as well even if the animal does die from it, but more likely to occur if the break isn't clean and complete... and that can be very difficult to witness...

Co2 is the best way to go if you can build a chamber that incorporates valves either on the canister itself or somewhere along the hose/entry point in order to control the flow of Co2.

For just 8 mice though you probably don't want to go through all the trouble. a swift blow to the head to knock them out before cervical dislocation (just in case it isn't done right) may be the best in this case but even that can be done wrong.... 

In short... pretty much any humane method is only humane once it is perfected and that generally is not within the first couple tries.... but almost all of the above methods done incorrectly is still less painful and horrifying than being crushed by a snake....

Since Sylvia brought up the importance of flow rates when administrating CO₂, there are a few other things that are worth noting. First, there are conflicting practices and protocols about the proper use of CO₂ euthanasia, even within the animal research community. Other factors, such as the concentration of CO₂ and O₂, as well as the flow rate of the CO2 being administered to the chamber all play a role in the procedure, and there is a general consensus that there is no perfect way of euthanizing animals with CO₂, as pretty much any approach can possibly cause some suffering. For instance, even low flow rates (~ 20%) may cause the animals to experience dyspnoea, whereas an immediate high concentration of CO₂ will cause pain in the upper respiratory tract until consciousness is lost. Behavioral symptoms include defecation, urination, shivering, hyperventilation, etc., and post-mortem examinations often show lung haemorrhage.

In the lab environment, there are a number of alternatives to using CO₂ for euthanasia, but for the use in a home setup, I personally prefer cervical dislocation. The learning curve is not very steep, and once you're experienced, it is very fast and effective.

For those reasons stated above I learned the hard way that I cannot ever keep and breed my own rodents for feeders. I tried cervical dislocation and was in tears with the first one because I didn't do it right and seeing...and hearing...their suffering is to much for me... I did 4 that way, the first one was by the worst but the others all screamed and some kicked and twitched.... Not something I can handle... After that I decided this was definitely not for me and thats why companies like rodent pro have a job.... so I got dry ice to kill off the remaining 5 rat babies, their mother, and the two mice breeders that never produced anyways. I tried to control the output of CO2 with the dry ice but that is pretty much impossible with minimal materials... and i could see the poor little things shaking and breathing so heavily desperately trying to find a way to get air... again.... NOT something I can handle.... 

Ironically feeding live or pre killed when it is absolutely necessary does not bother me at all... I guess in this case though it simply was not necessary and I saw it as needless suffering which I cannot condone for any animal...

The most humane way is carbon monoxide. Put the mice in a tub with a snug lid. Then get yourself a baseball size peice of dry ice and place it into a bowl of water and place that into the tub with the mice. Close the lid. In a matter of a few seconds, they will go to sleep and die peacefully with no pain. The carbon monoxide binds to the hemoglobin in their blood 7 times more than oxygen so they peacefully lose consciousness and die from lack of oxygen.

obviously someone didn't read the previous posts....

Dry ice is Carbon DIoxide(CO2)... not MONoxide(CO)....

Sorry folks type-o it is CO2 carbon dioxide, not CO carbon monoxide.

John - you may want to read my previous post and/or conduct a literature search on that topic. There has been quite a bit of academic interest in that topic, and while some of the specific aspects are still subject to debate, it seems quite clear that using carbon dioxide is far from the *perfect* way of euthanizing rodents. They certainly don't always "die peacefully with no pain".

I have used this method many times and never seen any signs of distress.Ive watched them just go to sleep.No method is perfect and if you create an environment of nothing but CO2 that would probably cause gasping etc. If done correctly it is better than cervical dislocation, freezing and many other more painful methods.

I don't doubt what you're saying, John, but there is a vast amount of empirical data that quantify the drawbacks to using this method. Yes, it is a standard protocol used in animal research, but the argument that it is better than cervical dislocation is not supported by experimental evidence. It is certainly more convenient to the keeper, but it is far from stress-free and painless.

Again, a quick review of some of the literature on this topic will help.

I've always recommended CO2. Cervical dislocation is much more painful if not done correctly. But to each their own. So, alterdimage, your choice. Give it a go at both and see which one you and the mice (hehe) are more comfortable with.

hold the head down on a table behind the neck with a butter knife handel, and pull the tail up...it breaks the neck.

There is no way I believe breaking the neck is more humane, faster, less painful or in any way better. I prefer CO2 because I have seen and done both methods and from my many experiences the use of CO2 is much more humane,less painful and theres much less chance of doing it incorrectly and causing additional suffering.

Actually, just pulling it by the tail during cervical dislocation can deglove the tail. I've known of it to happen before. Not a pretty sight.

"hold the head down on a table behind the neck with a butter knife handel, and pull the tail up...it breaks the neck." -Yes Im sure it does but its also cruel and much more painful and theres a good chance you will deglove the tail causing even more suffering. Again the gas is faster, easier and less tramatic and less painful.

Please re-read my posts. At no point am I arguing that cervical dislocation is the best method, or even that it is better than using CO₂. Instead, my argument is that it is certainly not inferior to using CO₂. Since the latter method is more often advocated and largely hands-off, people tend to be convinced that it is painless and more humane. My point in this discussion has been that using CO₂ is far from the perfect method of euthanizing rodents, and that the drawbacks are not based on my (or anyone else's) opinion, but rather on an overwhelming amount of experimental evidence. How many keepers are monitoring various aspects of the physiology of the rodents while they are being exposed to CO₂? How many keepers conduct post-mortem dissections to look for pulmonary haemorrhage following euthanasia? Exactly. Obviously, it is up to each keeper to decide between multiple imperfect methods. However, the pertinacious advocation of one imperfect method over another based on personal experience without a proper experimental setup or data is a bit silly when it comes to matters of animal physiology.

But don't take my word for it. Read some of the available primary literature and make your own decision.

Conlee KM, Stephens ML, Rowan AM, King LA. 2005. Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats. Laboratory Animals 39: 137-161.

Kirkden RD, Niel L, Stewart SA, Weary DM. 2008. Gas killing of rats: the effects of supplemental oxygen on aversion to carbon dioxide. Animal Welfare 17(1): 79-87.

McIntyre A, Lipman N. 2006. Controversy exists on the use of carbon dioxide (CO₂) for the euthanasia of rodents. Journal of the American Association for Laboratory Animal Science 45(4):7.

Niel LE. 2006. Assessment of distress associated with carbon dioxide euthanasia in laboratory rats. PhD Dissertation, The University of British Columbia.

Niel LE, Stewart SA, Weary DM. 2008. Effect of flow rate on aversion to gradual-fill carbon dioxide exposure in rats. Applied Animal Behaviour Science 109(1): 77-84. 

Smith W, Harrap SB. 1997. Behavioural and cardiovascular responses of rats to euthanasia using carbon dioxide gas. Laboratory Animals 31(4): 337-346.

If you have any published evidence that shows that CO₂ exposure causes rodents to "go to sleep and die peacefully with no pain", as you stated, I'd be very interested to see it.

So causing an extended period of suffocation is better than breaking the neck instantly? How exactly is it more painful? I think anyway to kill a rodent is just as painful as the next. In every situation, they die. If it is by your hand or a company's hand. Either way, they are raised for slaughter. I feed live mice because I feel it is less disgusting than feeding frozen. I am not going to feed my animal something that has been slowly killed by whatever method the company/person chooses, frozen, more than likely thawed out, refrozen, then thawed again. The chance of bacteria or other things is too high and honestly it is disgusting. I will feed my animals like they would be fed in nature, with live rodents. It taked the whole trouble out of killing them myself by slow torture. My python kills his prey in 2 minutes or less. I <3 fresh meat.

+Infinity to Nightflight. Damn good point.

*takes

Well I Made a Co2 chamber and it worked very well. There was just no way I could do the neck breaken thing....dont hav e the heart. I use a regulater on the Co2 so I controled the flow to a small steady stream.

Good for you alterdimage_red! I agree I hate the cervical dislocation method. I did it before I knew about the CO2 method and I hated doing it. The CO2 method is much more humane, fast and dry ice is cheap.

I'm glad that you were able to find a solution. however, based on available literature, cervical dislocation is actually MUCH more humane - if it's done properly. the gas takes at least 1 1/2 minutes and up to 3 (much longer for very young rodents); CD is instant, if properly performed.

I agree that it takes balls to do it. personally, I find it very unpleasant. however, it's quite a bit more humane - IF you do it right - because it's much faster.

and this comes from recommended euthanasia techniques for rodents, by the AVMA....

I couldnt disagree more about cervical dislocation. I am a senior RVT student at Los Angeles Peirce College and all of my instructors promote the CO2 method unless you can use uthanol, which you cannot do when your going to feed the rodent to another animal. Stress begins the minute you pick up a rodent to break its neck, and its so much easier to do this wrong its not even worth it. I have done the CO2 method hundreds of times and have never seen any signs of pain or stress or struggle. The CO2 afinity to hemoglobin is 7 times greater than oxygen. That means CO2 binds to hemoglobine 7 times more quickly than oxygen. So it happens very fast. Try each method yourself people and see which makes sense to you. But how many rodents are you going to torture with the cervical dislocation method before you master it well enough to cause minimal pain and distress? There is no learning curse with CO2. If you use a near air tight box and a large baseball peice of dry ice they lose consciousness very quickly and die shortly thereafter. Ive seen it and I belive in it more than dislocation, guillotine or any other method including freezing, which I have seen rodents chew out of containers before they got cold enough to fall asleep and then die. CO2 is best as far as my 20 years experieince trying every other method is concerned.

have you ever used CO2 in a clear chamber? I do research on mice and euthanize them in large numbers on a daily basis. it sure doesn't look painless to me, as they thrash and gasp in the chamber.

anyways, I simply don't agree with you. CO2 is much easier on the one doing the euthanasia, as you put the mice in a box and walk away for 5 minutes, but that doesn't mean their last few minutes is just a peaceful drifting off to sleep. I'm not saying "don't do it", I'm just saying don't fool yourself that CO2 is humane because it's not.

my herp society invited Dr Cindy Pekow, a world-respected research vet with the VA system, to teach people who wanted to learn how to use CD properly and effectively. it's only hard on the mice if you don't know what you're doing and it takes you several minutes.

I don't wish to argue further as you obviously feel very strongly, but I simply don't agree with your statements, based on my own experience (and the AVMA's euthasia guidelines). I stand by what I said.

Many animal research facilities use either CO₂ or cervical dislocation, and have done so for years. The benefit of using CO₂ is one of efficiency and practicality, but certainly not of being more humane. Many research facilities euthanize relatively large numbers of rodents, and CO₂ allows the personell to conduct the process faster and with less (though certainly not without!) training. Variables, such as CO₂ concentration and flow rate are critical to minimize stress and suffering on the rodents, and there is a vast amount of published evidence (see my previous post above) that neither is ever eliminated when using CO₂.

Aimee hit the nail on the head by stating that using CO₂ is much easier on the personell, but certainly not on the rodent. Remember that this is really not a matter of opinion, but rather a matter of evidence. The vast amount of published evidence on this topic is quite clear in that while neither method is perfect, cervical dislocation is more humane on the rodents (again, see my previous post for a list of select publications). Furthermore, bringing up personal affiliations do not necessarily support your argument. Instead, it only displays a disregard for scientific evidence on your part. For an RVT student, I'd really expect you to support your argument with published evidence, rather than the inductive reasoning that you have shown here.  

 What ever happened to just swinging them by the tail against a hard object, If done corectly it only takes one shot..just a wee bit harder than  if you were trying to stun it...."gas chambers and inhumane to freeze?"  if you buy frozen feeders look at how they come packed sometimes all huddled together from being frozen alive..what would be any different than putting them in a freezer, they just fall asleep. The same people who cry inhumane , if they had mice in their house im sure they wouldnt be thinking of humane ways to get rid of them...lmao