Carbon Dioxide (CO2) Euthanasia in Non-Rodent SpeciesApproved January 21, 1999 (Download)
Background: Carbon dioxide euthanasia, a frequently used method for small rodents, has also been proposed for use in rabbits. The 1993 Report of the AVMA Panel on Euthanasia recommends CO2 as acceptable for euthanasia, describing it as rapidly depressant and anesthetic, inexpensive, without accumulation of tissue residues, and without distortion of tissue architecture. CO2 is used for preslaughter anesthesia of swine in commercial slaughterhouses but an undesirable side effect of its use is an excitement stage upon induction of about 40 seconds before consciousness is lost. The report concludes with this qualifier: "Larger animals such as rabbits, cats, and swine appear to be more distressed by CO2 euthanasia; therefore other methods of euthanasia are preferable. " Local experience earlier with the use of CO2 for euthanasia in rabbits is consistent with this experience and recommendation.
Policy: CO2 should not be used for the euthanasia of animals such as rabbits, cats, and swine, which are reported to experience an undesirable initial excitatory phase upon induction. CO2 is an acceptable method of euthanasia for small rodents such as rats and mice.