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. 
Hutchinson, E., Avery, A., Van de Woude, S. 2005. Environmental enrichment for laboratory rodents. ILAR Journal 46(2), 148-161.

In this article, laws and guidelines relating to rodent enrichment are reviewed, the natural behaviors of select rodent species are discussed, and an overview of widely used types of enrichment in laboratory rodent management is...

Garner, J. P. 2005. Stereotypies and other abnormal repetitive behaviors: Potential impact on validity, reliability, and replicability of scientific outcomes. ILAR Journal 46(2), 106-117.

Normal behavior plays a key role in facilitating homeostasis, especially by allowing the animal to control and modify its environment. Captive environments may interfere with these behavioral responses, and the resulting stress may alter many...

Benefiel, A. C., Dong, W. K., Greenough, W. T. 2005. Mandatory enriched housing of laboratory animals: The need for evidence-based evaluation. ILAR Journal 46(2), 95-105.

Environmental enrichment for laboratory animals has come to be viewed as a potential method for improving animal well-being in addition to its original sense as a paradigm for learning how experience molds the brain. It...

Bayne, K. 2005. Potential for unintended consequences of environmental enrihment for laboratory animals and research results. ILAR Journal 46(2), 129-139.

Many aspects of the research animal's housing environment are controlled for quality and/or standardization. Of recent interest is the potential for environmental enrichment to have unexpected consequences such as unintended harm to the animal, or...

Baumans, V. 2005. Environmental enrichment for laboratory rodents and rabbits: Requirements of rodents, rabbits, and research. ILAR Journal 46(2), 162-170.

Environmental conditions such as housing and husbandry have a major impact on the laboratory animal throughout its life and will thereby influence the outcome of animal experiments. However, housing systems for laboratory animals have often...

Banjanin, S., Barley, J., Bell, L. et al. 2004. Environmental enrichment for guinea pigs: A Discussion by the Laboratory Animal Refinement & Enrichment Forum. Animal Technology and Welfare 3(3), 161-163.

The question was raised how the environment of guinea pigs can be best enriched in the research laboratory setting. In summary, social-housing is the most species-appropriate living environment for guinea pigs. If a research protocol...

Sherwin, C. M. 2004. E2 = 3R + 2Q: Calculating species-appropriate environmental enrichment. Proceedings of the International Congress of the International Society for Applied Ethology, 132 (Abstract).

Species appropriate environmental enrichment should be provided to improve both animal welfare and the quality of research data. For research animals, species-appropriate Environmental Enrichment (E2) can be considered as a function of the 3 Rs...

Key, D. 2004. Environmental enrichment options for laboratory rats and mice. Lab Animal 33(2), 39-44.

Environmental enrichment is the alteration of animals' microenvironment to provide them with the opportunity to perfrom species-specific behaviors that we perceive as positive, while reducing abnormal behaviors. [p. 39] Several interesting products are now available...

Guilarte, T. R., Toscano, C. D., McGlothan, J. L. et al. 2004. Environmental enrichment: Beneficial effects in a rodent model of lead neurotoxicity. Proceedings of the 4th World Congress on Alternatives and Animal Use in the Life Sciences - Alternatives to Laboratory Animals [ATLA] 32(Supplement), 236 (Abstract).

Using a rodent model of lead-induced neurotoxicity, we show that environmental enrichment reverses cognitive and molecular deficits induced by this developmental neurotoxicant... At weaning, pups were removed from the lead exposure and housed in isolation...

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...

Morris, T., Goulet, S., Morton, D. 2002. The International Symposium on Regulatory Testing and Animal Welfare: Recommendations on best scientific practices for animal care and regulatory toxicology. ILAR Journal 43(Supplement), S123-S125.

The key conclusion from the group's initial discussions was that enough information was now available to make robust recommendations for animal care best practices. Implementation, not information, is therefore the critical issue [p.123]... Well-implemented enrichment...

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...

Guittin, P., Decelle, T. 2002. Future improvements and implementation of animal care practices within the animal testing regulatory environment. ILAR Journal 43(Supplement), S80-S84.

The enrichment of the animals' environment will not likely affect the interpretation of the results, particularly if adequate controls are used. Appropriate enrichment methods can be chosen to be compatible with the aims of the...

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...

Fillman-Holliday, D., Landi, M. S. 2002. Animal care best practices for regulatory testing. ILAR Journal 43(Supplement), S49-S58.

General discussion of environmental enrichment. Many laboratory animal species, especially dogs and nonhuman primates, lose interest and stop using a particular device after exposure to it for some time (authors' experiences). It is best to...

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...

Fullwood, S., Hicks, T. A., Brown, J. C. et al. 1998. Floor space needs for laboratory mice: C57BL/6 males in solid-bottom cages with bedding. ILAR Journal 39(1), 29-36.

Different floor space allocations of cages that were barren except bedding were tested in groups of 3 male mice. Space reduction - from 129 to 32 square cm per mouse - had no impact on...

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)...