Refinement Database

Database on Refinement of Housing, Husbandry, Care, and Use of Animals in Research

This database, created in 2000, is updated every four months with newly published scientific articles, books, and other publications related to improving or safeguarding the welfare of animals used in research.

Tips for using the database:

  • This landing page displays all of the publications in the database.
  • Use the drop-down menus to filter these publications by Animal Type, Setting, and/or Topic.
  • Clicking on a parent category (e.g., Rodent) will include publications relating to all the items in that category (e.g., Chinchilla, Gerbil, Guinea Pig, etc.).
  • You may also add a keyword to further narrow your search.
  • Please note that at this time, only publications dated 2010 or later (with some exceptions) can be filtered by Animal Type and Topic, and only publications dated 2020 or later (with some exceptions) can be filtered by Setting. Most publications older than 2010 can only be searched by keyword. 
Patterson-Kane, E. G. 2003. Shelter enrichment for rats. Contemporary Topics in Laboratory Animal Science 42(2), 46-48.

Nest boxes are a simple and effective form of environmentalenrichment. Rats accept a wide range of nest-box types but have the strongest...preference for enclosed, opaque, thermoplastic boxes. ...Tubes have proven a relatively ineffective enrichment for...

Johnson, S. R., Patterson-Kane, E. G. 2003. Foraging as environmental enrichment for laboratory rats: A theoretical review. Animal Technology and Welfare 2, 13-22.

Foraging opportunities are a form of environmental enrichment with great potential to improve the welfare of animals in laboratories. Though commonly used with zoo animals, little evidence exists of their use in laboratories. Technicians or...

Applebee, K. A. 2002. Rodent environmental enrichment - animal welfare or human feel-good factor. Animal Technology and Welfare 1(2), 65-69.

This article discusses environmental enrichment for rodents, mainly mice and rats housed in conventional caging, in U.K. research facilities. Environmental enrichment should allow and encourage animals to perform normal behavioural patterns. Cage furniture cannot be...

Olsson, I. A. S., Dahlborn, K. 2002. Improving housing conditions for laboratory mice: A review of 'environmental enrichment'. Laboratory Animals 36, 243-270.

We have reviewed 40 studies carried out between 1987 and 2000, in which preferences as well as the effect of housing modifications have been studied. Mice will work for access to nesting material and make...

Fernández-Teruel, A., Giménez-Llort, L., Escorihuela, R. M. et al. 2002. Early-life handling stimulation and environmental enrichment: Are some of their effects mediated by similar neural mechanisms? Pharmacology Biochemistry and Behavior 73(1), 233-245.

Neonatal (early) handling (EH) and environmental enrichment (EE) of laboratory rodents have been the two most commonly used methods of providing supplementary environmental stimulation in order to study behavioral and neurobiological plasticity. A large body...

Cohoon, J. 2001. Nylabone on a chain. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 6(1), 2.

Both pigs and rabbits are having a great time banging the bone on the cage - they can swing it around, and they get to chew on it too!

Raje, S. S., Stewart, K. L. 2000. Group housing female guinea pigs. Lab Animal 29(8), 31-32.

Group housing [female] guinea pigs can save space and money, while improving housing standards. The authors describe enclosure design, enrichments, and husbandry techniques that facilitate group housing female guinea pigs. No data are included in...

Eskola, S., Lauhikari, M., Voipio, H.-M. et al. 1999. Environmental enrichment may alter the number of rats needed to achieve statistical significance. Scandinavian Journal of Laboratory Animal Science 26(3), 134-144.

The aim of this study was to evaluate whether two enrichment items, an aspen tube and block, have any impact on commonly analysed clinical chemistry and physiological parameters of Wistar rats and - more importantly...

Eskola, S., Lauhikari, M., Voipio, H.-M. et al. 1999. The use of aspen blocks and tubes to enrich the cage environment of laboratory rats. Scandinavian Journal of Laboratory Animal Science 26(1), 1-10.

Female and male outbred Wistar rats (n=48) were allocated into three groups at weaning; control, tube and block groups (n = 8 males and 8 females in each) Animals were conventionally housed for five weeks...

Eskola, S., Kaliste-Korhonen, E. 1998. Effects of cage type and gnawing blocks on weight gain, organ weights and open-field behaviour inWistar rats. Scandinavian Journal of Laboratory Animal Science 25(4), 180-193.

Two separate experiments were conducted to study the environmental enrichment value of aspen gnawing blocks in solid bottom cages with bedding '(SBC) and in grid floor cages without bedding (GFC), and the effects of housing...

Benefiel, A. C., Greenough, W. T. 1998. Effects of experience and environment on the developing and mature brain: Implications of laboratory animal housing. ILAR Journal 39(1), 5-11.

Immune system function appears to be enhanced in environmentally enriched rats relative to controls housed in standard cages.

Woolley, A. P. A. H. 1997. Requirements of biomedical research in terms of housing and husbandry for non-human primates: Pharmacology & Toxicology. Primate Report 49, 37-41.

The objective of toxicology and pharmacology studies is to detect change or variation from normal and to interpret the significance of such change, with the intention of assessing risk to man. With non-human primates (NHPs)...

Reinhardt, V., Roberts, A. 1997. Effective feeding enrichment for non-human primates: A brief review. Animal Welfare 6(3), 265-272.

There is a growing awareness that non-human primates kept in zoos and laboratories deserve more species-appropriate stimulation because of their biological adaptation to a challenging environment. Numerous attempts have been made to effectively emulate the...

Dahlborn, K., van Gils, B. A. A., van de Weerd, H. A. et al. 1996. Evaluation of long-term environmental enrichment in the mouse. Scandinavian Journal of Laboratory Animal Science 23(Supplement 1), 97-106. (Conference Paper)

It appears that mice who were enriched with both objects [nest box and plastic tube] and nesting material were more active, and spent less time on feeding and drinking, and they weight less compared to...

Kaliste-Korhonen, E., Eskola, S., Rekilä, T. et al. 1995. Effects of gnawing material, group size and cage level in rack on Wistar rats. Scandinavian Journal of Laboratory Animal Science 22(4), 291-299.

Han:Wist rats were housed after weaning in groups of one, two, three or four in stainless steel cages with aspen chip bedding, with or without wooden gnawing blocks. The use of the blocks was assessed...

Reinhardt, V., Reinhardt, A. 1992. Quantitatively tested environmental enrichment options for singly-caged nonhuman primates: A review. Humane Innovations and Alternatives in Animal Experimentation 6, 374-384.

Compatible companionship has a therapeutic effect on behavioral disorders, providing long- term stimulation of a great variety of species-typical social behavior patterns. Inanimate objects have little impact on behavioral disorders, but some of them provide...

Gilloux, I., Gurnell, J., Shepherdson, D. 1992. An enrichment device for great apes. Animal Welfare 1(4), 279-289.

The influence of an environmental enrichment feeding device (puzzle feeder), on activity and behaviour patterns of captive orang-utans, gorillas and chimpanzees was studied at London Zoo. General activity levels and behaviours directed towards the feeder...

Anonymous. 1992. Annual Reports: Howletts and Port Lympne Zoo Parks, UK. International Zoo News 39(1), 30-41.

Several structural enrichment enhancers are described. When a barrel with an opening in the front was hung from the roof of the siamang enclosure, our then solitary male, Mitch, spent much of his time looking...

Fajzi, K., Reinhardt, V., Smith, M. D. 1989. A review of environmental enrichment strategies for singly-caged nonhuman primates. Lab Animal 18(2), 23-35.

Comprehensive literature review dealing with the following topics: a) Group housing versus single housing; b) Enrichment strategies using inanimate objects; c) Socialization with conspecifics; d) Role of animal care staff.

Lee, G. H., Coe, J. C. 1988. Greenspace for primates. International Zoo News 35(3), 19-21.

Against most expectations, after 11 years, the Seattle gorilla exhibit is still lushly landscaped. The animals climb trees to favorite perches to get a better view and browse among certain favourite plants. All of these...

Boyd, J. 1988. Mice. Humane Innovations and Alternatives in Animal Experimentation 2, 49-50.

Description of an ingenious, simple method to minimize odor, provide species-appropriate nesting opportunities and to facilitate cleaning.

Gutwein, B. M., Fishbein, W. 1980. Paradoxical sleep and memory (I): Selective alterations following enriched and impoverished environmental rearing. Brain Research Bulletin 5(1), 9-12.

Mice were reared in either enriched (EE), social control, (SE), or impoverished (IE) environments for 30 days. Environmental enrichment results in a significant and selective increase in paradoxical sleep (PS, or REM sleep) and also...