{"title":"Evaluation of Carbon Dioxide Euthanasia of Female Sprague Dawley Rats Alone or With Unfamiliar Conspecifics.","authors":"Debra L Hickman","doi":"10.30802/AALAS-JAALAS-21-000051","DOIUrl":null,"url":null,"abstract":"<p><p>Most studies evaluating methods of euthanasia to date have focused on the euthanasia of individual animals. However, larger chambers are commonly used to euthanize multiple cages of animals at once. This study evaluated the use of a commercially available system for euthanasia of 1, 2, or 4 cages containing an individual female Sprague-Dawley rat using volume per minute displacement rates (VDR/min) of either 25% or 50% of 100% carbon dioxide. Animal wellbeing was assessed based on physiologic changes (serum noradrenaline and corticosterone) and behavioral assessments (relative frequency of rearing, line crossing, and grooming). The 25% VDR/min was associated with a significantly longer time to loss of consciousness, but this was not associated with significant physiologic or behavioral changes. The 50% VDR/min treatment group was associated with significant increases in the relative frequency of movement from 1 side of the cage to the other. Increases in the relative frequency of rears were detected in the 25% VDR/min treatment group when 2 or 4 rats were in the chamber as compared with a single rat in the chamber. The absence of significant physiologic changes suggest that the behavioral changes may have been associated with the novelty of the euthanasia experience rather than with distress. The location of the cage within the chamber did not significantly affect any of the measured parameters at either 25% or 50% VDR/min. These data suggest that groups of rats euthanized in these chambers are not experiencing decreases in their welfare.</p>","PeriodicalId":50019,"journal":{"name":"Journal of the American Association for Laboratory Animal Science","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8956221/pdf/jaalas2022000195.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the American Association for Laboratory Animal Science","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.30802/AALAS-JAALAS-21-000051","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2022/1/31 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"VETERINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Most studies evaluating methods of euthanasia to date have focused on the euthanasia of individual animals. However, larger chambers are commonly used to euthanize multiple cages of animals at once. This study evaluated the use of a commercially available system for euthanasia of 1, 2, or 4 cages containing an individual female Sprague-Dawley rat using volume per minute displacement rates (VDR/min) of either 25% or 50% of 100% carbon dioxide. Animal wellbeing was assessed based on physiologic changes (serum noradrenaline and corticosterone) and behavioral assessments (relative frequency of rearing, line crossing, and grooming). The 25% VDR/min was associated with a significantly longer time to loss of consciousness, but this was not associated with significant physiologic or behavioral changes. The 50% VDR/min treatment group was associated with significant increases in the relative frequency of movement from 1 side of the cage to the other. Increases in the relative frequency of rears were detected in the 25% VDR/min treatment group when 2 or 4 rats were in the chamber as compared with a single rat in the chamber. The absence of significant physiologic changes suggest that the behavioral changes may have been associated with the novelty of the euthanasia experience rather than with distress. The location of the cage within the chamber did not significantly affect any of the measured parameters at either 25% or 50% VDR/min. These data suggest that groups of rats euthanized in these chambers are not experiencing decreases in their welfare.
期刊介绍:
The Journal of the American Association for Laboratory Animal Science (JAALAS) serves as an official communication vehicle for the American Association for Laboratory Animal Science (AALAS). The journal includes a section of refereed articles and a section of AALAS association news.
All signed articles, including refereed articles and book reviews, editorials, committee reports, and news and commentary, reflect the individual views of the authors and are not official views of AALAS. The mission of the refereed section of the journal is to disseminate high-quality, peer-reviewed information on animal biology, technology, facility operations, management, and compliance as relevant to the AALAS membership. JAALAS accepts research reports (data-based) or scholarly reports (literature-based), with the caveat that all articles, including solicited manuscripts, must include appropriate references and must undergo peer review.