WORKING PARTY REPORT Recommendations for euthanasia of experimental animals: Part 1 Working Party: Mrs Bryony Close (Chair), Dr Keith Banister, Dr Vera Baumans, Dr Eva-Maria Bernoth, Dr Niall Bromage, DrJohn Bunyan, Professor Dr Wolff Erhardt, Professor Paul Flecknell, Dr Neville Gregory, Professor Dr Hansjoachim Hackbarth, Professor David Morton & Mr Clifford Warwick Correspondence to: Mrs B Close, Battleborough Croft, Battleborough Lane, Brent Knoll, Highbridge, Somerset TA9 4DS, UK This document was prepared for DGXI of the European Commission to be used with Directive 86/609/EEC of 24 November 1986, on the approximation of laws, regulations and administrative provisions of the Member States regarding the protection of animals used for experimental and other scienti®c purposes (No L 358, ISSN 0378-6978). It refers especially to Article 2(1) published by the European Commission in October 1995 which de®nes `humane method of killing' as `the killing of an animal with a minimum of physical and mental suffering, depending on the species'. This report is published in two parts. Contents to Part 1 This ®rst part comprises Sections 1 Acknowledgements 294 and 2 of the report, together with a Preface 294 reading list. Section 3 of the report, 1 Introduction 295 1.1 Objectives of euthanasia 295 together with the list of all references 1.2 De®nition of terms 295 cited in both parts and details of 1.3 Signs of pain and distress 296 training materials, will be published in 1.4 Recognition and con®rmation of death 296 the January 1997 issue of Laboratory 1.5 Personnel and training 297 Animals. Reprints combining both 1.6 Handling and restraint 297 parts of the report will be available 1.7 Equipment 297 1.8 Carcass and waste disposal 298 from Mrs S E Wolfensohn, Supervisor 2 General comments on methods of of Veterinary Services, University of euthanasia 298 Oxford, Veterinary Services, c/o 2.1 Acceptable methods of University Laboratory of Physiology, euthanasia 298 2.2 Methods acceptable for Parks Road, Oxford OX1 3PT, UK. unconscious animals 305 (Tel:+44(0)1865-272545, 2.3 Methods that are not Fax:+44(0)1865-272118, acceptable for euthanasia 306 Email: [email protected]). Further reading 309 Accepted 15 February 1996 LaboratoryAnimals (1996) 30, 293^316 294 Working Party Report Acknowledgements used in experiments and for other scienti®c purposes in assessing which method of We would like to thank the European euthanasia is the most humane and appro- Commission DGXI for providing funding for priate for the species of animal that they are this report and also Laboaratory Animals Ltd using. A brief description of each method is for publishing it and making reprints avail- given with reasons for accepting or rejecting able in order to achieve its widespread them. Details of how to carry out different distribution. methods are not provided; these may be We would like to thank the following found in references cited and in the recom- people and organizations who provided valu- mended reading list. able assistance and comments on the test: Dr Methods classi®ed as `acceptable' are those J Anderson (Animals (Scienti®c Procedures) that are considered humane for use on Inspectorate, UK Home Of®ce), Dr N conscious or lightly sedated animals. Other Baudrihaye (European Federation of Pharma- methods may be acceptable only if used on ceutical Industries' Associations), Professor J heavily sedated or unconscious animals. In Bourne (Institute for Animal Health, UK), Dr principle, all methods can be used on D Forbes (Laboratory Animal Science Asso- unconscious animals unless they are unac- ciation, UK), Professor K GaÈrtner (Medizi- ceptably dangerous to personnel or there is a nische Hochschule Hannover, Germany), Mr risk of the animal regaining consciousness J A Gregory (Institute of Animal Technology, before death occurs. Methods included under UK), Professor O HaÈnninen (Secretary those `acceptable for unconscious animals' General, ICLAS), Mrs R Harrison (UK), Dr F are those most frequently used in practice. R Homberger (University of Zurich, The last category of methods `not acceptable' Switzerland), Mr T D Hornett (Glaxo Re- are not to be used for the reasons provided in search and Development, UK), Dr K Iwarsson each case. (Karolinska Institutet, Sweden), Dr T Jenes- There are three main sections to this kog (National Board for Laboratory Animals report. Section 1 deals with general notes on (CFN), Sweden), Dr M Jennings (Royal legislative requirements of the 1986 Council Society for the Prevention of Cruelty to Directive of the EEC, general requirements of Animals, UK), Dr G Mahouy (Institut euthanasia, de®nitions of terms, and other d'HeÂmatologie, Universite de Paris, France), factors to be considered when killing experi- Professor R Murison (University of Bergen, mental animals. Section 2 provides informa- Norway), Mr P Nowlan (University of Du- tion on methods of euthanasia used for blin, Ireland), Professor C Rehbinder (Na- vertebrates and is divided broadly into tional Board for Laboratory Animals (CFN), acceptable physical and chemical methods, Sweden), Mr A Sainsbury (Institute of methods acceptable for insensible animals, Zoology, London), Professor P Schambye and those methods not considered accepta- (Board of Animal Experiments Inspectorate, ble. Section 3 covers each group of species Denmark), Dr W Scharmann (Bundesge- from ®sh to primates with general informa- sundheitsamt, Germany), Professor U tion pertaining to the species, including Schatzmann (UniversitaÈt Bern, Switzerland), recommendations on embryonic and larval Dr D Straughan (UK), Dr P Terpstra (CRC forms. Methods of euthanasia are listed and Contract Research Center, Belgium), Profes- brie¯y discussed. At the end of each species sor J E van Dijk (University of Utrecht, the section, there is a table summarizing the Netherlands), Mr D Wilkins (Eurogroup for recommendations for that species. Animal Welfare), Dr J Wong (Canadian There are, in addition, comprehensive lists Council on Animal Care). of cited references and literature recom- mended for further reading (divided into Preface general and species groups), together with information on audiovisual training materi- This report has been produced in order to als that may be used in training programmes assist personnel concerned with animals to encourage humane euthanasia practices. Euthanasia of experimental animals 295 It is recommended that all personnel read physical and mental suffering, depending on Section 1. If information is required about a the species. particular method, this may be obtained in Whilst this document provides recom- Section 2, and if information is required mendations for the euthanasia of experi- about a particular species, this may be found mental animals, it is strongly recommended in Section 3. that controls and guidelines issued in other EC directives and regulations for the eutha- nasia of animals be taken into consideration 1 Introduction (e.g. Council Directive 93/119/EC (Commis- sion of the European Communities 1993)). Animals are killed in laboratories or breeding establishments for various reasons: 1.1 Objectives of euthanasia . at the end of an experiment or when there The primary criteria for euthanasia in terms might be continuing adverse effects; of animal welfare are that the method be . to provide blood and other tissues for a painless, achieve rapid unconsciousness and scienti®c purpose; death, require minimum restraint, avoid . when levels of pain, distress and suffering excitement, is appropriate for the age, are likely to exceed the designated level; species, and health of the animal, must . where the health or welfare of the animals minimize fear and psychological stress in the are grounds for concern; animal, be reliable, reproducible, irreversible, . when they are no longer suitable for simple to administer (in small doses if breeding; possible) and safe for the operator, and, so far . unwanted stock or those with unsuitable as possible, be aesthetically acceptable for characteristics, for example, type or sex, the operator. are not needed. 1.2 Definition of terms The Council Directive of 24 November The word euthanasia means a gentle death 1986 (Commission of the European Com- and should be regarded as an act of humane munities 1986) on the approximation of laws, killing with the minimum of pain, fear and regulations and administrative provisions of distress. the Member States regarding the protection Consciousness is the state of awareness of of animals used for experimental and other a normal animal when it can perceive stimuli scienti®c purposes (86/609/EEC) excludes from its external environment and respond in the killing of an animal from the legal the normal behaviour of an awake individual. de®nition of an experiment (Article 2(d)) if it Unconsciousness will be used to mean is carried out using the least painful method insensibility to external stimuli as would be accepted in modern practice and in accor- expected in coma or during general anaes- dance with the scienti®c purpose of collect- thesia. Two main ways of measuring insen- ing blood and other tissues from the killed sibility are to look at the physical responses animals, therefore leaving these procedures and responses in the central nervous system outside the protection of the Directive. This at the cortical level. document is designed to assist all those Pain may be de®ned as `an aversive sensory concerned with experimental animals in experience that elicits protective motor deciding which method