SPCA is concerned that the growing body of evidence indicates carbon dioxide (CO2) is not a humane method of euthanasia, despite its continued use in research, testing, and teaching. Currently, use of CO2 is recommended under strict parameters for concentration and flow rate, and the animal’s life stage. SPCA is concerned with the amount of time an animal experiences aversive states of welfare such as anxiety, air hunger, pain before they become unconscious prior to death. Our organisation supports efforts to move away from use of CO2 as a killing method, or to refine use of CO2 so that it is a less aversive experience for animals, such as mixing of other gases which would lead to unconsciousness sooner and with fewer side effects.

SPCA advocates for more funding and research into the refinement or phase-out of the use of carbon dioxide (CO2) as a killing method.

While CO2 is used to kill animals in research, testing, and teaching, SPCA advocates for institutions to review current protocols to ensure they are consistently written and conducted in accordance with the 2020 American Veterinary Medical Association (AVMA) Guidelines for the Euthanasia of animals.