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Post by angel on Jan 20, 2024 23:57:18 GMT -8
I hope a question like this is allowed on here but I assume it is because this is a very real part of pet ownership. I've heard some people euthanize their small pets at home using various methods, some painful and some not. From what I have read, the most popular method of DIY euthanasia is the co2 method. Many sources claim it is pain-free and that studies have shown it causes no distress to the animals before death, however I'm a bit confused on how that is possible. I remember watching a youtube video ( I found it actually) about what stimuli is guaranteed to cause a fear response in any human. They found that elevated levels of co2 in the blood cause fear and panic as the brain recognizes that you are suffocating. If gerbils are like humans in this way, this would definitely not be a stress-free euthanasia. Thankfully all of my gerbils are happy and healthy and I do not need to euthanize any of them, I just like to be prepared for the future in case anything does happen. Does anyone have any insight on the co2 method or any other methods that are painless both mentally and physically? This website explains some options for euthanizing hamsters, although it doesn't go into detail about which ones are pain & stress free, if any. I would never want euthanize a pet at home unless there is a pain & stress free way to do so.
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Post by betty on Jan 21, 2024 9:08:39 GMT -8
Absolutely. Speedy, timely and safe euthanasia is a must for pet ownership, and should always be a confident and talked-about option when discussing health care for poorly pets. The CO 2 method is widely used in the rat and mouse breeding world - whether as an aside for reptile care or the pursuit of fewer pups in breeders main litters. It is quick and easy to do, doesn't need a veterinary qualification/licence to use, and doesn't render the rodent toxic to eat to various carnivores. I was always led to believe by comments of it on various forums that any discomfort was minimal. I think you will find out more about the process and studies of it from rat or mouse forums (because the vast majority of gerbil breeders and keepers don't follow this path. Gerbil breeders want to keep all their gerbils from all their litters alive - and often go to great lengths to do so. Gerbils also aren't a common 'food' rodent as they can't be housed in large enough groups to make this financially viable long term, amongst other reasons. I know that a veterinary euthanasia involves 'knocking them out' first with a gas like humans have in hospitals (although I am not sure what this is off the top of my head) before the fatal injection - so this is deemed to be as painless as it can be. LilyandDaisy may have some experience/knowledge of the hamster information you linked to - but I have never really explored this as an option myself, so may not be too much help here.
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Post by TJ's Rodent Ranch on Jan 21, 2024 11:22:07 GMT -8
This is a great question.
Betty has pretty much covered what I would say, so I don't have a whole lot to add. As far as I've heard, since the CO2 method is gradual, it is painless. Even if it's not completely painless, however, it's probably the most painless way of DIY euthanasia. The most stressful part of the process is most likely them being locked in a tight space.
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Post by angel on Jan 21, 2024 11:33:05 GMT -8
I found some info that basically confirms my assumptions about the effects of Co2 inhalation in rodents in this article: pubmed.ncbi.nlm.nih.gov/15901358/#:~:text=There%20is%20clear%20evidence%20in,careful%20reconsideration%20of%20its%20use. "Carbon dioxide (CO2) is the most commonly used agent for euthanasia of laboratory rodents, used on an estimated tens of millions of laboratory rodents per year worldwide, yet there is a growing body of evidence indicating that exposure to CO2 causes more than momentary pain and distress in these and other animals." "Internationally, animal research standards specify that any procedure that would cause pain or distress in humans should be assumed to do so in non-human animals as well". "There is clear evidence in the human literature that CO2 exposure is painful and distressful, while the non-human literature is equivocal. However, the fact that a number of studies do conclude that CO2 causes pain and distress in animals indicates a need for careful reconsideration of its use."
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Post by betty on Jan 21, 2024 11:43:35 GMT -8
Oh, that isn't really ideal to know. Thanks for digging deeper on it and sharing.
Hmm. Maybe the definition of 'pain-free' is where the loophole is in reference to lab animals. Or they avoid the word pain-free entirely in place of a description of a physical action instead.
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Post by angel on Jan 21, 2024 12:28:15 GMT -8
You're probably right. My thinking was that if Co2 inhalation causes a panic response in the human brain due to realization you are suffocating then it must be the same in rodents. But since there is no physical action harming them, people assume it does not cause any form of distress or pain. It doesn't seem like that is the case though. That being said, I am going to look into other forms of diy euthanasia should it ever come up that I need to do it. I read that you can use sleeping pills or certain other substances to put them to sleep. Maybe a combination of that first and then the co2 method after would be painless since they will be knocked out. One substance I read about was pentobarbital, which you are supposed to inject. I believe it's what vets use to euthanize animals though, so I'm not sure how one would obtain that.
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Post by betty on Jan 21, 2024 12:36:02 GMT -8
Pento - at least in the UK - is a controlled drug for sure.
(sorry - p.text changed my comment to pheno originally)
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Post by angel on Jan 21, 2024 13:39:09 GMT -8
I also found this excerpt from this link which suggests that co2 euthanasia can be humane if co2 is displaced at a rate of 10-30%, however it also mentions that a higher rate may be required, but not too high as being exposed to high levels of co2 at once can cause significant distress. It's a bit confusing. I don't think that it would be possible to accurately ensure the correct amount of co2 displacement using any diy method, so I am now looking into ways to pre-sedate them before using the co2 method, or just using another method altogether. "Several recent reviews provide in-depth analyses of the controversy about CO2 euthanasia.16,104 To summarize briefly, carbon dioxide is an anesthetic at high concentrations (30% to 40% in rats),109,110 and it renders animals unconscious before they die of respiratory arrest and hypoxia. Other inert gases (for example, nitrogen, argon) can asphyxiate animals, but they are not considered humane methods of euthanasia as a sole agent for rodents because the animals may experience distress when they are conscious during asphyxiation. Similarly, time to death is prolonged when CO2 is supplemented with oxygen, so the practice of euthanizing animals with a CO2-O2 mixture 32,101 is no longer recommended.63 Carbon dioxide has the disadvantage of reacting with the fluid in mucous membranes to form carbonic acid, which can produce a stinging sensation in the eyes and throat in some humans.24,32,107 It can also produce anxiety responses in rodents at concentrations above 20%.46 In the past, CO2 was administered by putting animals in a prefilled chamber or delivering CO2 at a very high rate (approximately 70%) of volume displacement. This resulted in rapid loss of consciousness (loss of cortical brain activity within 30 s in mice)21 but the animals could experience significant distress from the nociceptive effect of the CO2. Under the current AVMA Guidelines, when using CO2 as the sole agent, the objective is to achieve loss of consciousness before a noxious dose is delivered. Although the displacement rate of 10% to 30% is supported by literature,45,48 and many institutions have invested in engineered systems that can reliably deliver CO2 at this rate, more recent studies show that this rate, especially at the low end of the range, is not optimal or effective for every species or strain.13,30,32,42,46,56,61,62,69,73 CO2 exposure with suboptimal flow rates can result in animals remaining conscious for a prolonged period while being exposed to an atmosphere that, at least for humans, causes a distressing sensation of breathlessness.46 Also, the prolonged induction time (3 to 10 min to achieve 100% fill) is prohibitively long for some experimental studies, for either logistical or experimental reasons. At the time of writing this review, the AVMA's new proposed rate is 30% to 70%.5 In recognition of the difficulty in delivering a CO2 exposure paradigm that uniformly produces loss of consciousness before producing distress, Canadian Council on Animal Care has issued guidelines that require anesthesia or sedation (for example with isoflurane) prior to CO2 exposure when practical22 (Table 3). However, assessment of the wellbeing of rodents exposed to isoflurane, especially with repeated exposures, is not well-characterized and may also cause distress prior to causing loss of consciousness."
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Post by LilyandDaisy on Jan 21, 2024 13:57:30 GMT -8
I have read quite a bit about the CO2 method too (and although I have always had my rodents euthanised by a vet, have kept it in the back of my mind as a kind of backup). I've also understood the discomfort to be minimal when it is performed properly. The level of CO2 needs to increase gradually. If a rodent is put straight into a chamber filled with CO2, they will experience lung burning and probably panic before they fall unconscious. A gradual drop in oxygen levels caused by CO2 is often said to feel like being very drowsy and falling asleep, but we can never really be sure what an animal experiences.
I suppose that is really the problem, that we never truly know what our pets experience in their last moments, no matter the method of euthanasia. That includes euthanasia performed by a vet. The kind of death we all hope for for our pets, that of just falling asleep in their nest and never waking up, rarely happens and most deaths involve some amount of fear, pain or suffering sadly. Vets almost universally euthanise small rodents by first anaesthetising them with gas, and then injecting pentobarbital into the heart. Owners are rarely allowed to be present for this, so if there was any struggle or anxiety as the rodent went to sleep, the owner would probably never know. On the other hand, with home euthanasia, the owner is going to be aware of and have to bear the feeling of responsibility for any amount of suffering the rodent displays. So there is an aspect of "out of sight, out of mind". That said, I do believe that vet-performed euthanasia is about as humane as euthanasia can possibly get. Although I wouldn't think badly of an owner who performed a compassionate and careful home euthanasia, I think most people should just go to the vet if at all possible.
By the way, I don't believe that hamster website is a reliable source at all. I'm very concerned by the next bit about euthanasia by Tylenol poisoning. Tylenol (aka paracetamol) poisoning is a horrendous, and unreliable, way to die and I don't know how on earth the authors expect a person to administer 10 paracetamol tablets to a hamster in a humane manner. I know the article doesn't exactly promote this method, but I'm not sure why the author felt it needed to be described at all?
And then it goes on to discuss using controlled benzodiazepines and barbiturates at home, which is deeply concerning. Pentobarbital, midazolam, and diazepam are all very much controlled drugs which are illegal to use on your pet at home without a prescription. They also don't contain opiates even though the author seems to think they do. I wouldn't recommend trusting any information on that website.
I wouldn't recommend using any kind of drug at home to attempt euthanasia because rodents process drugs differently to humans. Syrian hamsters, for example, have super efficient livers. Their livers are so efficient, that's it's impossible for a Syrian hamster to get drunk by oral means. In the best case scenario, the drugs just might not work. In the worst case, the rodent might react in an expected way and die an unpleasant death, or may not be die but suffer organ damage. Either of those scenarios would also leave you as the owner in a risky legal situation if you attempted the home drug euthanasia despite having a vet available.
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Post by angel on Jan 21, 2024 16:43:48 GMT -8
That website was very questionable, it was just one of the first ones to come up when I searched. I would definitely cry if I ever had to euthanize my pet myself but in the end I would take solace in the fact that it was for the best. Things like this always bring up questions for me about why life can be so cruel. I would definitely feel extremely guilty if I unknowingly caused them pain and suffering during a euthanasia, which is why I try to find answers to these kinds of questions ahead of time in case a situation comes up where a home euthanasia is necessary.
Now that I think about it, it makes total sense that a more gradual release of co2 would result in unconsciousness before asphyxiation, thus making the process humane. I remember a few years ago when we had a very long power outage in the wintertime and they put out a reminder not to sit in a running car in your garage to warm yourself up. This is because the co2 from the exhaust fills up the closed space and causes you to fall unconscious before asphyxiating. Apparently it had happened not long ago to some people because they were not aware of what would happen so they put out that reminder.
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Post by Markpd on Jan 22, 2024 12:37:49 GMT -8
Interesting discussion this, I don't have much to add except about an article I read in New Scientist a few(?) years ago talking about new potentially more humane ways to euthanise cattle (in slaughter houses IIRC). One method discussed was reducing oxygen levels, this apparently avoids the panic of feeling breathless like high CO2 levels can, certainly in people it induces some level of stupor, confusion, & drowsiness leading onto to simply falling asleep. And as an avid watcher of Air Crash Investigation these affects from low oxygen levels are confirmed there in incidences where cabin pressure is lost at high altitude! That's why they have to descend fast when that happens! (The recent incident of the 737 losing a door plug was not at high altitude, 16,000ft IIRC).
I don't know if it would be practical at home though to have a chamber where you could somehow reduce oxygen levels without increasing CO2.
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