Editing Animal euthanasia (section)

=== Inhalants ===
{{main|Controlled-atmosphere killing}}
Gas anesthetics such as [[isoflurane]] and [[sevoflurane]] can be [[controlled-atmosphere stunning|used for euthanasia]] of very small animals. The animals are placed in [[gas chamber|sealed chambers]] where high levels of anesthetic gas are introduced. Death may also be caused using [[carbon dioxide]] once unconsciousness has been achieved by inhaled anesthetic.<ref name=ANU>{{cite web |work=Australian National University |title=Laboratory Animal Euthanasia |format=DOC |url=http://www.anu.edu.au/ro/ORI/HumaneEuthanasia.doc |access-date=30 November 2007 |archive-url=https://web.archive.org/web/20070819094116/http://www.anu.edu.au/ro/ORI/HumaneEuthanasia.doc |archive-date=19 August 2007 |url-status=dead }}</ref> Carbon dioxide is often used on its own for euthanasia of wild animals.<ref>{{Cite web |url=http://icwdm.org/wildlife/euthanasia/carbondioxide.asp |title=Animal Euthanasia Information - Carbon doxide gas (Internet Center for Wildlife Damage Management |access-date=17 February 2011 |archive-url=https://web.archive.org/web/20161001201251/http://icwdm.org/wildlife/euthanasia/carbondioxide.asp |archive-date=1 October 2016 |url-status=dead }}</ref> There are mixed opinions on whether it causes distress when used on its own, with human experiments lending support to the evidence that it can cause distress and equivocal results in non-humans.<ref name="pmid15901358">{{cite journal |vauthors=Conlee KM, Stephens ML, Rowan AN, King LA |title=Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats |journal=[[Laboratory Animals (journal)|Laboratory Animals]] |volume=39 |issue=2 |pages=137–61 |date=April 2005 |pmid=15901358 |doi=10.1258/0023677053739747 |s2cid=14005155 |url=https://animalstudiesrepository.org/cgi/viewcontent.cgi?article=1015&context=acwp_lab|doi-access=free }}</ref> In 2013, the American Veterinary Medical Association (AVMA) issued new guidelines for carbon dioxide induction, stating that a flow rate of 10% to 30% volume/min is optimal for the humane euthanasia of small rodents.<ref name="2013 AVMA Guidelines for the Euthanasia of Animals: 2013 Edition">[https://www.avma.org/kb/policies/documents/euthanasia.pdf 2013 AVMA Guidelines for the Euthanasia of Animals]</ref>

[[Carbon monoxide]] is often used, but some states in the US have banned its use in animal shelters:<ref>{{cite web |last1=Purtill |first1=Corinne |title=The gas chamber is being officially retired in California as a method of execution—for animals |url=https://qz.com/700599/the-gas-chamber-is-being-officially-retired-in-california-as-a-method-of-execution-for-animals |website=QZ |date=7 June 2016 |access-date=26 February 2024}}</ref><ref>{{cite web |title=Banned In 19 States, Animal Gas Chamber Still Legal In Pennsylvania |url=https://www.wtae.com/article/banned-in-19-states-animal-gas-chamber-still-legal-in-pennsylvania/7455400 |website=WTAE |date=2 February 2012 |access-date=26 February 2024}}</ref> although carbon monoxide poisoning is not particularly painful, the conditions in the gas chamber are often not humane.<ref>{{Cite web |url=http://news.nationalgeographic.com/news/2005/04/0411_050411_peteuthanasia.html |title=Animal Gas Chambers Draw Fire in U.S. - National Geographic |access-date=17 February 2011 |archive-url=https://web.archive.org/web/20110629001053/http://news.nationalgeographic.com/news/2005/04/0411_050411_peteuthanasia.html |archive-date=29 June 2011 |url-status=dead }}</ref> [[Nitrogen]] has been shown to be effective, although some young animals are more resistant to the effects,<ref name="pmid17423118">{{cite journal |vauthors=Quine JP, Buckingham W, Strunin L |title=Euthanasia of small animals with nitrogen; comparison with intravenous pentobarbital |journal=The Canadian Veterinary Journal |volume=29 |issue=9 |pages=724–6 |date=September 1988 |pmid=17423118 |pmc=1680841 }}</ref> and it currently is not widely used.{{cn|date=February 2024}}

The use of gas chambers is not the most humane form of euthanasia as it can take up to 20 minutes to fully euthanize the animal. If the chambers are not calibrated correctly or the animal is ill, the process is only delayed further which can cause more harm to the animal.<ref>{{Cite web |title=Bringing an end to inhumane euthanasia {{!}} The Humane Society of the United States |url=https://www.humanesociety.org/resources/bringing-end-inhumane-euthanasia |access-date=2024-05-05 |website=www.humanesociety.org |language=en}}</ref>