IACUC Default Social and Environmental Enrichment Program for Research Animals

Prologue
In order to enhance animal wellbeing, minimize animal stress, promote consistency, and comply with regulatory requirements, the IACUC commissioned a subcommittee to develop default enrichment standards, specifically defining housing conditions and socialization opportunities, for all species used in research at Emory University with the exception of nonhuman primates (addressed separately). Persons interested in the Emory Environmental Enrichment Policy for nonhuman primates are referred to: http://www.emory.edu/IACUC/pdfs/EEPolicyNHP.pdf.

The appointed Enrichment Subcommittee, consisting of Michael J. Huerkamp, DVM, DACLAM (Chair), Mollie Bloomsmith, M.S., PhD, David Knight, BS, Denyse Levesque, DVM, Deborah Mook, DVM, DACLAM and Jennifer K. Pullium, MVB, DACLAM, was charged to craft draft default science-based social and environmental enrichment programs for all research animals excluding nonhuman primates. The committee met on consecutive months from April through September 2005, reviewed 89 or more pertinent citations from the literature, and developed the specifics of the “Default Social and Environmental Enrichment Program” described below. This program was reviewed and approved by vote of a quorum of the full IACUC (Dr. Sam Speck, Chair) on November 16, 2005. For purposes of audit or historical interest, the subcommittee notes and proceedings have been archived by the IACUC office.

Introduction
The environment may influence the validity, reliability and replicability of experiments by introducing abnormal animals into studies, increasing variability within the population, and altering the number and type of individual animals between laboratories, respectively (Garner, 2005). In the context of the research animal, the environment consists of both physical attributes (e.g., lighting, temperature, cage design and complexity) as well as the nature of social interactions. In the proper care and use of research animals, the availability or suitability of enrichment must be considered in the provision of the environment and specifically with opportunities to exhibit species-typical behaviors and activity (Clark, et al, 1996).

When animals are unable to perform species typical behaviors and control their environment, unintended stress results and may become manifested as abnormal behaviors, both maladaptive and malfunctional (Garner, 2005). Abnormal behaviors in a population are similarly potentially confounding to science because they are usually expressed inconsistently across the spectrum of the group (Garner, 2005). Their expression varies by genetic background and developmental experience and may be difficult to mitigate with aging (Garner, 2005). As such, successful enrichments reduce or prevent the occurrence of malfunctional and maladaptive behaviors (Garner, 2005) through appropriately lifelong (e.g., from development onward) social and environmental enrichment (Baumans, 2005; Garner, 2005).

An important enrichment caveat is that social, environmental, dietary and other supplementations intended for improvement of animal well-being may alter important aspect’s of an animal’s physiology and development in ways not easily predictable based on what is already known (Benefiel, et al, 2005; Hutchinson, et al, 2005). Enrichment is a research variable that must be sensibly managed and must be biologically relevant. The effective delivery of enrichment minimizes or removes all non-research-related variables, while ensuring the scientific validity, repeatability and replicability of research (Garner, 2005; Weed and Raber, 2005). In essence, enrichment enables “good welfare” to equal “good science”.

Abbreviations and Definitions
“ Animal” – for purposes of the default enrichment program, “animal” is defined as to comprise all vertebrate species used in research at Emory University with the exception of nonhuman primates covered by a separate policy and program.

AWAR – Animal Welfare Act Regulations. Detailed regulations and standards for implementing the federal Animal Welfare Act of 1966 and subsequent revisions. Found in Title 9 of the Code of Federal Regulations (9CFR), Chapter 1, Subchapter A, Parts 1, 2 and 3.

“Social Animals” – within the context of use at Emory University, the following species are defined as being social: dogs, cats, pigs, sheep, rabbits, guinea pigs, gerbils, certain vole species, pigeons, chickens, and songbirds. Although not necessarily social species, amphibians do have biological needs for certain environmental enrichments.

General Principles

1. Social animals will be housed in compatible pairs or groups, rather than individually, provided such housing is not contraindicated by the protocol in question and does not pose undue risk to the animals in question (Clark, et al, 1996).
2. The structural habitat will include objects that increase opportunities for the expression of species-typical postures and activities and enhance the animals’ well-being (Clark, et al, 1996).
3. Particularly when social animals must be housed alone, other forms of enrichment must be provided to compensate for the absence of other animals unless scientifically contraindicated (Clark, et al, 1996).
4. Exemptions from some or all of the requirements of the default enrichment program for scientific reasons, and if for all or part of the time maintained at the university, must be documented in the protocol and specifically approved by the IACUC (Institutional Animal Care and Use Guidebook. 2002. 2nd edition, ARENA/OLAW, p. 50).
5. Qualified institutional veterinarians have the authority to exempt specific animals from inclusion in the enrichment program for reasons related to health, condition or well-being. The exemption and rationale must be documented in a medical record. Veterinarians doing so are obligated to review the status of the exemption at least every 30 days and renew it or void it accordingly (AWAR §3.8(d), §3.81(e)).
6. This program should be revised with the addition of new species to the census or in the case where significant new information emerges or approaches to enrichment come to be the norm.

Default Enrichment Program Description by Species

Cats: Behaviorally compatible cats must be socially housed. Group enclosures should have sufficient resting places off the floor to accommodate every cat. Scratching posts and visual barriers should be provided. Multiple litter boxes, feed and water bowls should be distributed around the enclosure with at least one station for every two to three cats. If a cat is to be housed singly because of social incompatibility or is post-operative, it should be given a hiding place and opportunities for increased human interaction. Cats housed singly for scientific purposes should be within sight and sound of other cats and given toys, other manipulanda and opportunities for increased human interaction.

Chicks: Brooder chicks from 3 to approximately 14 days of age should be kept on contact bedding at a density of 30 to each brooder tray (1000 square inches (7.5 sf) with 42” of water trough and 21” of linear feeder) until the age of 1 week and then 15 to a tray until 2-4 weeks. Any chicks left after 4 weeks should be moved to an appropriate pen or cage with a roost, litter, dust bath and at least 0.5-1.0 square feet per bird.

Dogs: Canines should be socially housed in compatible pairs or small groups. Each home enclosure must have a platform, bench, step, bed, etc., to allow each dog an elevated and/or partially enclosed resting space. Likewise, each dog should have access to at least one toy when in their home enclosure. These toys should be rotated to maintain interest. If dogs cannot be compatibly housed continuously, intermittent social housing of 30 minutes per day, 5 days per week is allowable. Dogs housed individually must be within sight of other dogs. Those kept singly for more than 2 weeks should be given extra human interaction including petting, soothing speech, playing, and grooming for at least 10 minutes, 3 days per week.

(Gerbils: To be determined.)

Guinea Pigs: Guinea pigs are to be kept in social groups contained within pens and provided shelter space sufficient to contain all of the pen inhabitants simultaneously.

Mice: Mice are to be group-housed in breeding or compatible unisex groups on contact bedding with nesting material. Unfamiliar males, such as those acquired as adults from commercial breeders or breeding males given sexual rest, should be housed singly.

Pigeons: Pigeons should be housed in compatible social groups in flight cages with at least 2 square feet of floor space per bird, enriched with grains in the bedding, and with at least weekly opportunities to bathe.

Rabbits: Post-pubescent rabbits (>4 months of age) should be housed singly with the ability for visual, auditory and olfactory association with conspecifics. Rabbits housed singly must be provided a toy or other manipulanda on the outside/top of the cage on a regular basis to allow for exploratory behaviour. Nursing kits and rabbits < 4 months of age should be housed in groups, but accorded appropriate space per regulatory standards.

Rats: Rats should be socially housed unless scientific justification for not doing so is provided by the investigator. When single housing is required, enhanced environment enrichment meeting the needs of retreat space must be provided. Housing in high density ventilated caging systems with filter tops meets this need. Otherwise, for rats in open polycarbonate cages a PVC pipe section of appropriate diameter or shelter equivalent will suffice.

Sheep: Sheep should be socially housed in compatible pairs or small groups, unless exempted for experimental reasons by the IACUC, or for health or behavioral reasons by the attending veterinarian. If sheep must be individually housed, position them in such a way that they can see at least one conspecific, because visual isolation is stressful for sheep. Stressful research manipulations (e.g., venipuncture, drug application) should be accomplished within the presence of a familiar conspecific. Where there is likelihood of a single sheep remaining on census at a single cite, experimental plans must account for the timely use of the remnant. Sheep are particularly susceptible to isolation stress and those not obviously coping with social isolation will be subject to IACUC endpoints including veterinary interventions (e.g., tranquilization) or euthanasia. Sheep must be provided a diet high in roughage, to allow species typical feeding and rumination, and to reduce the likelihood of stereotyped behaviors.

Songbirds: Songbirds should be housed in socially compatible groups with perches, feeders, watering devices, and cuttlebone as appropriate for the species.

Swine: Behaviorally compatible pigs must be socially housed including, if necessary, combining pigs of compatible size and disposition to meet this need. Substrates should be provided to enable rooting behavior. Examples of such substrates include: plastic or bowling balls loose on the cage floor, baby pools or equivalent filled with balls and treats.. Swine should be provided manipulanda suspended from the pen side, such as hanging ropes, chains, tires or rubber tubes, for play and exploration.

Voles: Voles should be housed in social groups with males closely monitored for fighting minimally meeting the “Guide” requirements for hamsters. Nesting material in the form of hay, straw, paper products, or nestlets must be provided to fulfill burrowing needs. To maintain pheromonal cues and facilitate continued compatibility, part of the old nesting material should be transferred to the new cage at cage change.

Xenopus laevis: African clawed frogs must be housed in tanks with a population density not exceeding one per 2 liters tank water volume and as otherwise stipulated by facility SOP. With respect to the latter, water treatment, circulation and quality may stipulate that greater volumes be accorded per head. For animals housed with direct exposure to room light, refuges or retreats must be provided in the form of pipes, flower pots, or submerged plastic boxes unless the environment is already sufficiently dark.

REFERENCES

Cited References

• Baumans V. 2005. Environmental enrichment for laboratory rodents and rabbits: Requirements of rodents, rabbits and research. ILAR J 46(2): 162-70.
• Benefiel A. C., Dong W. K., and W. T. Greenough. 2005. Mandatory “enriched” housing of laboratory animals: The need for evidence-based evaluation. ILAR J 46(2): 95-105.
• Clark, J. D., R. L. Baldwin, K. A. Bayne, et al. 1996. Guide for the Care and Use of Laboratory Animals, National Research Council, Washington, DC.
• Garner J. P. 2005. Stereotypies and other abnormal repetitive behaviors: Potential impact on validity, reliability, and replicability of scientific outcomes. ILAR J 46(2): 106-17.
• Hutchinson E., Avery A. and S. VandeWoude. 2005. Environmental enrichment for laboratory rodents. ILAR J 46(2): 148-61.
• Weed J. L., and J. M. Raber. 2005. Balancing animal research with animal well-being: Establishment of goals and harmonization of approaches ILAR J 46(2): 118-28.

General References

• Bayne K.A. 2005. Potential for unintended consequences of environmental enrichment for laboratory animals and research results. ILAR J 46(2): 129-39.
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Cat References

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Chick References

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• Virginia Cooperative Extension Service: http://www.ext.vt.edu/pubs/poultry/factsheets/5.html

Dog References

• Campbell, S.A., Hughes, H.C., Griffin, H.E., Landi, M.S., and Mallon, F.M. 1988. Some effects of limited exercise on purpose-bread Beagles. American Journal of Veterinary Research, 49(8): 1292-1301.
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• Fox, M.W. and Stelzner, D. 1966. Behavioral effects of differential early experience in the dog. Animal Behaviour, 14: 273-281.
• Hennessy, M.B., Williams, M.T., Miller, D.D., Douglas, C.W., and Voith, V.L. 1998. Influence of male and female petters on plasma cortisol and behaviour: can human interaction reduce the stress of dogs in a public animal shelter? Applied Animal Behavioral Science, 61: 63-77.
• Hubrecht, RC., Serpell, J.A., and Poole, T.B. 1992. Correlates of pen size and housing conditions on the behaviour of kenneled dogs. Applied Animal Behaviour Science, 34(4): 365-383.
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• Hubrecht, R. 1995. Dogs and dog housing. In: Smith, C.P. and Taylor, V., Environmental Enrichment Information Resources for Laboratory Animals: 1965-1995: Birds, cats, dogs, farm animals, ferrets, rabbits, and rodents. AWIC Resource Series No 2, Us Department of Agriculture, Beltsville MD and Universities Federation for Animal Welfare , Ptters Bar, Herts, UK. Pp. 49-62.
• Hughes, H.C., Campbell, S., and Kenney, C. 1989. The effects of cage size and pair housing on exercise of beagle dogs. Laboratory Animal Science, 39(4): 302-305.
• Loveridge, G.G. 1998. Environmentally enriched dog housing. Applied Animal Behaviour Science, 59:101-113.
• Lynch, J.J. and Gantt, W. (1968). The heart rate component of the social reflex in dogs: the conditional effects of petting and person. Cond. Reflex., 3: 69-80.
• Tuber, D.S., Miller, D.D., Caris, K.A., Halter, R., Linden, F., and Hennessy, M.B., 1999. Dogs in animal shelters: Problems suggestions and needed expertise. Psychtr. Sci.,10: 379-386.
• Wells, D.L. 2004a. A review of environmental enrichment for kenneled dogs, Canis Familiaris. Applied Animal Behaviour Science, 85: 307-317.
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• Wells, D.L. and Hepper, P.G. 1998. A not on the influence of visual conspecific contact on the behaviour of sheltered dogs. Applied Animal Behaviour Science, 60:83-88.
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• Wolfle, T.L. 1987. Control of stress using non-drug approaches. J.A.V.M.A. ,1991: 1219-1221.

Guinea Pig References

• Laboratory Animal Refinement & Enrichment Forum. 2004. Environmental enrichment for guinea pigs. Animal Technology and Welfare. 3(3): 161-163.

Pigeon References

• Rupiper D. http://members.aol.com/duiven/basicnee.htm
• Virginia Cooperative Extension Service: http://www.ext.vt.edu/pubs/poultry/factsheets/10.html
• Vriends M.M. 1988. Pigeons: A Complete Pet Owner’s Manual. Barron’s, New York.

Rabbit References

• Cowan D.P. Group living in the European rabbit: mutual benefit or resource localization? Journal of Animal Ecology. 56:779-795, 1987.
• Bayne K.A. Environmental enrichment of nonhuman primates, dogs and rabbit used in toxicology studies. Toxicologic Pathology. 31(Suppl.): 132-137, 2003.

Rodent References

• Belz, E.E., J.S. Kennell, R. K. Czambel, R.T. Rubin and M.E. Rhodes. 2003. Environmental enrichment lowers stress-responsive hormones in singly housed male and female rats. Pharmacology, Biochemistry and Behavior 76: 481-486.
• Bingham, W.E., and W.J. Griffiths, Jr. 1952. The effecto of different environments during infancy on adult behavior in the rat. J Comp Physiol Psychol 45: 307-312.
• Forgays, D.G. and J.M. Read. 1962. Crucial Perods for free-environmental experience in the rat. J Comp Physiol Psychol 55: 816-818.
• Greenough, W.E. and A. Benefiel. 2003. Enriching the housing of the laboratory rodent: How might it affect research outcomes? “The Development of Science-based Guidelines for Laboratory Animal Care” National Academy of Sciences. Proceedings of the November 2003 International Meeting.
• Hebb, D.O. 1949. The Organization of Behavior. New York: John Wiley & Sons.
• Moncek, F., R. Duncko, B.B. Johansson, and D. Jezova. 2004. Effect of environmental enrichment on stress related systems in rats. J Neuroendocrinology 16: 423-431.
• Smith A. L., and D. J. Corrow (2005) Modifications to husbandry and housing conditions of laboratory rodents for improved well-being. ILAR J 46(2): 140-47.
• Van Loo P.L. and V. Baumans. 2004. The importance of learning young: The use of nesting material in laboratory rats. Lab Animal 38: 17-24.

Sheep References

• Crockram, M.S., Ranson, M., Imlah, P., Goddard, P.J., Burells, C., and Harkiss, G.D. 1994. The behavioural, endocrine and immune responses of sheep to isolation. Animal Production, 58: 389-400.
• Dwyer, C.M. and Bornett, H.L.I. 2004. Chronic stress in sheep: assessment tools and their use in different management conditions. Animal Welfare, 13: 293-304.
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• Hargreaves, A.L. and Hutson, G.D. 1990. Some effects of repeated handling on stress responses in sheep. Applied Animal Behaviour Science, 26: 253-256.
• Hinch, G.N. and Lynch, J.J. (995. Comfortable quarters for sheep and goats. Department of animal science, University of New England, Armidale NSW 2350, Australia.
• Lynch, J.J., Hinch, G.N., and Adams, D.B.1992. The behaviour of sheep: Biological principles and implications for production. CAB International & Commonwealth Scientific and Industrial Organization (CSIRO): Wallingford.
• Mateo, J.M., Walker, R.I., Cullis, B.R., and Luff, M.F. 1991. Effects of differential handling on the behaviour of domestic ewes (Ovis aries). Applied Animal Behaviour Science, 32: 45-54.
• Parrott, R.F., Misson, B.H., and de la Riva, C.F. 1994. Differential stressor effects on the concentrations of cortisol, prolactin and catecholamines in the blood of sheep. Res. Vet Sci., 56(2): 234-239.

Songbird References

• Gaunt A.S. and L.W. Oring, eds. 1997. Guidelines to the Use of Wild Birds in Research. 2d ed. North American Ornithological Council, Washington, D.C.

Swine References

• Beattie, V.E., 1995. Effect of rearing environment and change of environment on the behavior of gilts. Applied Animal Behavior Science. 46: 57-65.
• de Groot, J., de Jong, I.C., Prelle, I.T., and Koolhaas, J.M.. 2000. Immunity in barren and enriched housed pigs differing in baseline cortisol concentration. Physiol Behav 71(3-4): 217-23.
• de Jong, I.C., Prelle, I.T., van de Burgwal, J.A., Lambooij, E., Korte, S.M., Blokhuis, H.J., and Koolhaas, J.M. 2000. Effects of environmental enrichment on behavioral responses to novelty, learning, and memory, and the circadian rhythm in cortisol in growing pigs. Physiol Behav. 68(4): 571-8.
• de Jong, I.C., Ekkel, E.D., van de Burgwal, J.A., Lambooij, E., Korte, S.M., Ruis, M.A., Koolhaas, J.M., Blokhuis, H.J. 1998. Effects of strawbedding on physiological responses to stressors and behavior in growing pigs. Physiol. Behav. 64(3): 303-10.
• Grandin, T., 1983. The effects of rearing environment on the behavior of young pigs. Journal of Animal Science, 57 (supplement 1): 137.
• Grandin, T. 1987. Toys, mingling and driving reduce excitability in pigs. Journal of Animal Science, 65(1): 230-231.
• Grandin, T. 1988. Environmental enrichment for confinement pigs. Livestock Conservation Institute Proceedings.
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• Morgan, C.A. 1998. The effects of straw bedding on the feeding and social behavior of growing pigs fed by means of single-space feeders. Applied Animal Behavior Science, 58: 23-33.
• Rodarte, L.F., et al. 2004. The effect of environmental manipulation on behavior, salivary cortisol, and growth of piglets weaned at 14 days of age. J Appl Anim Welf Sci, 7(3): 171-9.

Vole References

• Clarke, J. 1999. Voles. In: The UFAW Handbook on The Care and Management of Laboratory Animals, seventh edition, volume 1, chapter 20, pp. 331-344, 1999.
• Solomon, N.G. and Vanderbergh, J.G. 1994. Management, Breeding, and Reproductive Performance of Pine Voles. Laboratory Animal Science. 44(6): 613-617, 1994.
• Donnelly, T.M. and Quimby F.W. 2002. Biology and Diseases of Other Rodents. In: Laboratory Animal Medicine, 2nd edition, chapter 7, pp. 279-281.

Xenopus laevis References

• Halliday, T.R. 1999. Amphibians In: The UFAW Handbook on The Care and Management of Laboratory Animals, seventh edition, volume 2, chapter 6, pp. 90-102.
• Major, N. and Wassersurg, R.J. 1998. Survey of Current Techniques in the Care and Maintenance of the African Clawed Frogs (Xenopus laevis). Contemporary Topics, 37(5), pp. 57-60.
• Kreger, M.D. 2002. Comfortable Quarters for Amphibians and Reptiles in Research Institutions. In: Comfortable Quarters for Laboratory Animals, Reinhardt, V. and Reinhardt A. (eds). Animal Welfare Institute, Washington DC, pp. 109-114.
• Hilken, G., Dimigen, J., and Iglauer, F. 1995. Growth of Xenopus laevis under different laboratory rearing conditions. Laboratory Animals, 29: 152-162.
• Brown, M.J. and Nixon, R.M. 2004. Enrichment for the captive environment-The Xenopus laevis. Animal Technology and Welfare, 3(2): 87-95.
• Reed, B.T. Guidance on the housing and care of the African clawed frog-Xenopus laevis. Research Animals Department-RSPCA. 2005.
• Schultz, T.W. and Dawson, D.A. 2003. Housing and Husbandry of Xenopus for oocyte production. Lab Animal, 32(2): 34-39.
• Hayes, M.P., Jennings, M.R. and Mellen, J.D. 1998. Enrichment for amphibians and reptiles. In: Second Nature-Environmental enrichment for captive animals, Smithsonian Institute, Washington, pp. 205-235.