Ethics of Research involving animals
Reduction - continuation III
Refining housing, husbandry and care
12.13 Laboratory animals spend most of their time in cages or pens, so their immediate environment, and the care they receive, has a major impact on their well-being. Standards for laboratory housing are defined in the Home Office Codes of Practice for the husbandry and care of animals18 and corresponding European guidelines.19 These represent minimum standards only and are mainly concerned with satisfying the physiological rather than the behavioural needs of the animals. For example, rats are social animals that, in the wild, have large home ranges, eat a varied diet and exhibit a range of complex behaviours.20 Yet according to current guidelines for laboratory animals, two adult rats can be kept for the whole of their life in a cage with a floor area of 700 cm2 (the size of a large shoe box) containing a few millimetres of sawdust and perhaps a tube to hide in (see also Box 12.1). Unmodified, this is a very confined and barren environment.
12.14 Refinement of laboratory animal husbandry requires the provision of an ‘enriched’ environment that satisfies not only the physiological, but also the behavioural needs of the animals and these have to be identified for each species and strain. One way of doing this is to use the results of behavioural studies, which measure an animal’s preference for, or motivation to obtain, a particular resource, such as a nest box for chickens, access to social companions in rats, and rooting materials for pigs (see Box 4.2).
12.15 It is easier to identify the needs of some species than others. In the case of rats and mice there is a significant scientific literature on their behavioural needs. Similarly, nesting material, facilities for animals to hide, and material for gnawing are fundamental requirements for both rats and mice.21 It is therefore relatively straightforward to ascertain from the scientific literature what the laboratory environment must provide in order to try and satisfy the basic needs of rats and mice.22 Important aspects of Refinement for rodent husbandry are listed in Box 12.1.
| Box 12.1: Husbandry – needs of mice and rats A good-quality environment providing for a range of activities would include:
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12.16 Once species-specific needs have been identified, ways of satisfying the animals’ needs in a laboratory setting may be developed. Further to improving the welfare of animals and the quality of scientific results, implementations of Refinements have the benefit that animals housed with a good quality and quantity of space are frequently easier to handle and work with. Research shows that rats group-housed in enriched environments are quicker to learn new tasks, less stressed, more confident, less aggressive and in better general condition than singly housed animals. Such benefits can improve staff morale and encourage further exploration of opportunities to implement all Three Rs next page
Footnotes18 Home Office (1989) Code of Practice for the Housing and Care of Animals Used in Scientific Procedures (London: HMSO). See
also the supplementary codes which concern a range of more specific research contexts, available at:
http://www.homeoffice.gov.uk/comrace/animals/legislation.html#codes. Accessed on: 9 May 2005.
19 European Community (1986) Council Directive 86/609 on the Approximation of Laws, Regulations, and Administrative
Provisions of the Member States Regarding the Protection of Animals Used for Experimental and Other Scientific Purposes,
OJ L.358. (Luxembourg: EC).
20 See Berdoy M (2003) The Laboratory Rat: A Natural History, available at http://www.ratlife.org. Accessed on: 3 May 2005.
21 See Fillman-Holliday D and Landi MS (2002) Animal Care Best Practices for Regulatory Testing ILAR J V43 Supplement;
Sherwin CM (2002) Comfortable quarters for mice in research institutions, available at:
http://www.awionline.org/pubs/cq02/Cq-mice.html. Accessed on: 9 May 2005; Lawlor MM (2002) Comfortable quarters for
rats in research institutions, available at: http://www.awionline.org/pubs/cq02/Cq-rats.html. Accessed on: 9 May 2005.
22 Chmiel DJ and Noonan M (1996) Preference of laboratory rats for potentially enriching stimulus objects Lab Anim 30:
97–101; Manser CE, Elliott HE, Morris TH and Broom DM (1996) The use of a novel operant test to determine the strength of preference for flooring in laboratory rats Lab Anim 30: 1–6; Townsend P (1997) Use of in-cage shelters by laboratory rats Anim Welfare 6: 95–103; Patterson-Kane EG, Hunt M and Harper DN (1999) Behavioural indexes of poor welfare in laboratory rats J Appl Anim Welfare Sci 2: 97–110.