Guide for the Care and Use of Laboratory Animals - Office of ...

124 GUIdE FOR ThE CARE ANd USE OF LAbORATORy ANIMALSand larval life forms depending on species and gestational age (Artwohl etal. 2006).The selection of specific agents and methods for euthanasia will dependon the species involved, the animal’s age, and the objectives of the protocol.Generally, chemical agents (e.g., barbiturates, nonexplosive inhalantanesthetics) are preferable to physical methods (e.g., cervical dislocation,decapitation, use of a penetrating captive bolt); however, scientific considerationsmay preclude the use of chemical agents for some protocols.Although carbon dioxide (CO 2) is a commonly used method for rodenteuthanasia, there is ongoing controversy about its aversive characteristicsas an inhalant euthanasia agent. This is an area of active research (Conleeet al. 2005; Danneman et al. 1997; Hackbarth et al. 2000; Kirkden et al.2008; Leach et al. 2002; Niel et al. 2008) and further study is needed tooptimize the methods for CO 2euthanasia in rodents (Hawkins et al. 2006).The acceptability of CO 2as a euthanasia agent for small rodents should beevaluated as new data become available. Furthermore, because neonatalrodents are resistant to the hypoxia-inducing effects of CO 2and require longerexposure times to the agent (Artwohl et al. 2006), alternative methodsshould be considered (e.g., injection with chemical agents, cervical dislocation,or decapitation; Klaunberg et al. 2004; Pritchett-Corning 2009).It is essential that euthanasia be performed by personnel skilled in methodsfor the species in question and in a professional and compassionatemanner. Special attention is required to ensure proficiency when a physicalmethod of euthanasia is used. Death must be confirmed by personneltrained to recognize cessation of vital signs in the species being euthanized.A secondary method of euthanasia (e.g., thoracotomy or exsanguination)can be also used to ensure death. All methods of euthanasia should bereviewed and approved by the veterinarian and IACUC.Euthanizing animals is psychologically difficult for some animal care,veterinary, and research personnel, particularly if they perform euthanasiarepetitively or are emotionally attached to the animals being euthanized(Arluke 1990; NRC 2008; Rollin 1986; Wolfle 1985). When delegatingeuthanasia responsibilities, supervisors should be sensitive to this issue.REFERENCESAnderson LC. 2007. Institutional and IACUC responsibilities for animal care and use educationand training programs. ILAR J 48:90-95.ACLAM [American College of Laboratory Animal Medicine]. 2001. Position Statement on RodentSurgery. Available at www.aclam.org/education/guidelines/position_rodentsurgery.html; accessed January 7, 2010.AORN [Association of Operating Room Nurses]. 2006. Recommended practices for trafficpatterns in the perioperative practice setting. AORN J 83:681-686.Arluke A. 1990. Uneasiness among laboratory technicians. Lab Anim 19:20-39.