# Anesthesia and Euthanasia of Amphibians and Reptiles Used in Scientific Research: Should Hypothermia and Freezing Be Prohibited?



## davecalk (Dec 17, 2008)

In 2020 the AVMA, American Veterinary Medical Association, updated their Guidelines on Euthanasia.

*AVMA guidelines for CO2 Euthanasia *is discussed. Pages 28 – 31.
*AVMA guidelines for CO2 Euthanasia and Amphibians & Reptiles *starts in the last paragraph. Pg 30.
*AVMA overall Euthanasia guidelines for Captive Amphibians and Reptiles*. Pages 92 – 94.
*AVMA CO2: Advantages / Disadvantages* */ General Recommendations* Pg 31

I am in the process of updating the article I did years ago regarding the use of CO2 and how to generate it because aspects of it dealt with the question of Euthanasia.

This is a paper done by BioScience and The American Institute of Biological Sciences.

Anesthesia and Euthanasia of Amphibians and Reptiles Used in Scientific Research: Should Hypothermia and Freezing Be Prohibited?

It discusses the issues of Euthanasia of Amphibians & Reptiles and questions the AVMA's assertions that the only valid form of Freezing that is ethical is Rapid Freezing where animals that are below 4 g can be euthanized by being placed in liquid N2.

This article did not come up when I did a search Dendroboard search.

I think it would be a worthy avenue of discussion.

*Abstract*
Current research guidelines for ectothermic tetrapod vertebrates prohibit the use of cold as an adjunct to gaseous anesthesia, and they prohibit freezing as a means of euthanasia of these same animals. Here, we argue that those guidelines merit re-evaluation. Under natural conditions, numerous amphibians and reptiles experience large variations of body temperature, and life at low temperatures is natural. In tropical species less tolerant of cold, nociception is likely to be extinguished at low temperatures because of the anesthetizing actions of cold on membranes and cold block of nerve conduction. Physical principles and physiological data suggest that smaller ectothermic vertebrates do not experience pain attributable to ice crystals that form during freezing. Therefore, whole-body cooling, followed by freezing, should be a humane form of euthanasia for numerous smaller ectothermic species. In addition, we believe that cooling offers a humane and useful means of supplementing currently acceptable methods of anesthesia.

Background and perspective
Concerns Regarding Current AVMA Guidelines for the Euthanasia of Amphibians and Reptiles
The measurement of pain
Natural history and the evolution of tolerance of cold
Cold or freezing as appropriate anesthesia or euthanasia for amphibians and reptiles
Validation of the endpoint
Conclusions
*Cooling of tropical species*
Cooling of low-elevation tropical species to temperatures approaching 0°C can kill tropical species without formation of ice crystals in body fluids or tissues (Wilson et al. 2009). Therefore, we consider either rapid cooling in an ice bath or slower cooling in a refrigerator and/or freezer (Shine et al. 2015) to be a humane method of euthanasia for small tropical amphibians and reptiles because low temperatures will suppress nerve and brain function as discussed above. Moreover, the use of chemical agents for euthanasia might induce equal or greater levels of distress (see below). Generally, freezing of zebrafish is allowed by current guidelines, and we suggest this practice also should be extended to small species of tropical amphibians and reptiles.


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## Socratic Monologue (Apr 7, 2018)

I've emailed the author of this article to try to get a copy, as there are none available online. 

Reevaluating the use of hypothermia for anesthetizing and euthanizing amphibians and reptiles

Would be an interesting counterpoint.


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## Christine86 (Feb 4, 2021)

This method is also known by fishkeepers, but freezing your fish is really not done anymore! Most people use clove oil and give the sick fish an overdose. As I'm pretty new in the PDF world, I never thought about the fact how to do this with a frog. 

Here are a few (fish related) links that might be interesting:









How To Humanely Euthanize Your Fish | RateMyFishTank.com


If your fish is suffering, you may want to consider euthanasia as an option to humanely end his pain.




www.ratemyfishtank.com







BBC NEWS | Science/Nature | Fish do feel pain, scientists say


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## Socratic Monologue (Apr 7, 2018)

Keep in mind that the "Rate My FIsh Tank" article is using the 2013 recommendations, not the current ones. That article claims to have been updated the middle of 2021, but that's simply false; beyond the outdated AVMA material, they include a link to Drs. F&S, which was dissolved in early 2019. 

Not a bad article otherwise, but current recommendations should also be consulted.


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## Christine86 (Feb 4, 2021)

Yes this is an old article, but when in 2013 freezing fish is already considerded an old fashion way, how is that in 2021? For sick fish clove oil seems to be a more humane option, so why freeze them?


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## Socratic Monologue (Apr 7, 2018)

Christine86 said:


> Yes this is an old article, but when in 2013 freezing fish is already considerded an old fashion way, how is that in 2021? For sick fish clove oil seems to be a more humane option, so why freeze them?


To be clear, I wasn't attempting to contradict your point, but only warn people that the article may have other shortcomings that are due to it depending on dated sources.

Scientifically grounded understandings don't always progress from 'complete superstition' to 'primitive' to 'old fashioned' to 'modern' to 'cutting edge' to 'futuristic' in a regular linear fashion, though ("Windmills??? They used those 500 years ago -- clean coal is the way forward!"). The paper that @davecalk cited in the thread starter is advocating, with good reason based in reducing the suffering of animals as far as I can see from reading the paper, a return to an older method. New or old doesn't matter; whether something is supported by evidence and solid reasoning matters.


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