title: Euthanasia of neonatal mice with carbon dioxide.
abstract: Exposure to carbon dioxide (CO2) is the most prevalent method used to euthanize rodents in biomedical research. The purpose of this study was to determine the time of CO2 exposure required to euthanize neonatal mice (0 to 10 days old). Multiple groups of mice were exposed to 100% CO2 for time periods between 5 and 60 min. Mice were placed in room air for 10 or 20 min after CO2 exposure, to allow for the chance of recovery. If mice recovered at one time point, a longer exposure was examined. Inbred and outbred mice were compared. Results of the study indicated that time to death varied with the age of the animals and could be as long as 50 min on the day of birth and differed between inbred and outbred mice. Institutions euthanizing neonatal mice with CO2 may wish to adjust their CO2 exposure time periods according to the age of the mice and their genetic background.
authors.affiliation: Animal Services, Charles River Laboratories, 251 Ballardvale St, Wilmington, Massachusetts 01887, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Pritchett
authors.forename: Dorcas
authors.initials: D
authors.lastname: Corrow
authors.forename: Jason
authors.initials: J
authors.lastname: Stockwell
authors.forename: Abigail
authors.initials: A
authors.lastname: Smith
mesh_terms: D000367:Age Factors; D000769:Anesthesia, Inhalation / Q000662:veterinary*; D000827:Animal Welfare; D000818:Animals; D000830:Animals, Laboratory; D000831:Animals, Newborn; D021461:Animals, Outbred Strains; D002245:Carbon Dioxide / Q000008:administration & dosage; D037901:Euthanasia, Animal / Q000379:methods*; D019570:Inhalation Exposure; D007756:Laboratory Animal Science / Q000379:methods*; D051379:Mice; D008815:Mice, Inbred Strains; D013045:Species Specificity; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide