Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Nov 2;9(11):911.
doi: 10.3390/ani9110911.

Humanely Ending the Life of Animals: Research Priorities to Identify Alternatives to Carbon Dioxide

Aline R Steiner  1 , Shannon Axiak Flammer  2 , Ngaio J Beausoleil  3 , Charlotte Berg  4 , Regula Bettschart-Wolfensberger  5 , Rebeca García Pinillos  6 , Huw D W Golledge  7 , Michael Marahrens  8 , Robert Meyer  9 , Tobias Schnitzer  10 , Michael J Toscano  11 , Patricia V Turner  12 , Daniel M Weary  13 , Thomas C Gent  14
Affiliations

Humanely Ending the Life of Animals: Research Priorities to Identify Alternatives to Carbon Dioxide

Aline R Steiner et al. Animals (Basel). .

Abstract

: The use of carbon dioxide (CO2) for stunning and killing animals is considered to compromise welfare due to air hunger, anxiety, fear, and pain. Despite decades of research, no alternatives have so far been found that provide a safe and reliable way to induce unconsciousness in groups of animals, and also cause less distress than CO2. Here, we revisit the current and historical literature to identify key research questions that may lead to the identification and implementation of more humane alternatives to induce unconsciousness in mice, rats, poultry, and pigs. In addition to the evaluation of novel methods and agents, we identify the need to standardise the terminology and behavioural assays within the field. We further reason that more accurate measurements of consciousness state are needed and serve as a central component in the assessment of suffering. Therefore, we propose a roadmap toward improving animal welfare during end-of-life procedures.

Keywords: Animal welfare, carbon dioxide, stunning, killing, euthanasia, rodents, poultry, pigs, aversion, air hunger..

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Structural overview of research priorities.
See this image and copyright information in PMC

References

    1. Abeyesinghe S.M., McKeegan D.E., McLeman M.A., Lowe J.C., Demmers T.G., White R.P., Kranen R.W., van Bemmel H., Lankhaar J.A., Wathes C.M. Controlled atmosphere stunning of broiler chickens. I. Effects on behaviour, physiology and meat quality in a pilot scale system at a processing plant. Br. Poult. Sci. 2007;48:406–423. doi: 10.1080/00071660701543089. - DOI - PubMed
    1. Beausoleil N.J., Mellor D.J. Introducing breathlessness as a significant animal welfare issue. N. Z. Vet. J. 2015;63:44–51. doi: 10.1080/00480169.2014.940410. - DOI - PubMed
    1. Parshall M.B., Schwartzstein R.M., Adams L., Banzett R.B., Manning H.L., Bourbeau J., Calverley P.M., Gift A.G., Harver A., Lareau S.C. An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea. Am. J. Respir. Crit. Care Med. 2012;185:435–452. doi: 10.1164/rccm.201111-2042ST. - DOI - PMC - PubMed
    1. Banzett R.B., Pedersen S.H., Schwartzstein R.M., Lansing R.W. The Affective Dimension of Laboratory Dyspnea. Am. J. Respir. Crit. Care Med. 2008;177:1384. doi: 10.1164/rccm.200711-1675OC. - DOI - PMC - PubMed
    1. Rhudy J.L., Meagher M.W. Fear and anxiety: divergent effects on human pain thresholds. Pain. 2000;84:65–75. doi: 10.1016/S0304-3959(99)00183-9. - DOI - PubMed