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. 
Bechard, A., Nicholson, A., Mason, G. 2012. Litter size predicts adult stereotypic behavior in female laboratory mice. JAALAS 51(3), 407-411.

Stereotypic behaviors are repetitive invariant behaviors that are common in many captive species and potentially indicate compromised welfare and suitability as research subjects. Adult laboratory mice commonly perform stereotypic bar-gnawing, route-tracing, and back-flipping, although great...

Gaskill, B. N., Lucas, J. R., Pajor, E. A. et al. 2012. Heat or insulation: Behavioral titration of mouse preference for warmth or access to a nest. PLOS ONE 7(3), e32799.

In laboratories, mice are housed at 20-24C, which is below their lower critical temperature (30C). This increased thermal stress has the potential to alter scientific outcomes. Nesting material should allow for improved behavioral thermoregulation and...

Buijs, S., Maertens, L., Tuyttens, F. A. M. et al. 2011. Glucocorticoid metabolites in rabbit faeces - Influence of environmental enrichment and cage size. Physiology & Behavior 104(3), 469-473.

The concentration of glucocorticoid metabolites (GCM) in rabbit faeces has been suggested as a non-invasive indicator of stress. In the present study, GCM concentrations were measured in faeces of fattening rabbits kept in groups of...

Poggiagliolmi, S., Crowell-Davis, S. L., Alworth, L. C. et al. 2011. Environmental enrichment of New Zealand white rabbits living in laboratory cages. Journal of Veterinary Behavior 6(6), 343-350.

The primary goal of environmental enrichment should be the avoidance of abnormal behaviors in laboratory animals such as rodents, lagomorphs, dogs, cats, and nonhuman primates. A total of 13 male single-housed New Zealand White rabbits...

Bechard, A., Meagher, R., Mason, G. 2011. Environmental enrichment reduces the likelihood of alopecia in adult C57BL/6J mice. JAALAS 50(2), 71-74.

Barbering (incessant grooming) is an abnormal behavior causing alopecia and commonly affects various strains of laboratory mice, including C57BL/6J. Barbering-induced alopecia is a potential symptom of brain impairment and can indicate a stressful environment. We...

Tosa, N., Yoshimatsu, K., Arikawa, J. 2011. Effect of environmental enrichment after the occurrence of wet bedding created by mice and abnormal fur in mice. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 779-780 (Abstract #P161).

In management of laboratory animals, wet bedding created by mice and abnormal fur in mice cause problems on housing, leading to negative effects both on the wellbeing of mice and on the validity of experimental...

Reed, M., Goldsteen, D. L., Moore, E. et al. 2011. Environmental enrichment program in transgenic mouse breeding colonies. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 779 (Abstract #P160).

Results of studies on the benefits of environmental enrichment in group-housed mice and breeding colonies are often inconsistent and conflicting. After observing a significant drop in some of the genetically engineered mice (GEM) breeding colonies...

Paula, A. A., Goyeneche, L., Crispo, M. 2011. Refining housing and husbandry techniques in transgenic mice through environmental enrichment. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 777 (Abstract #P148).

Dynamic changes in housing and husbandry techniques based on the concept of 3Rs should be included as routine practice in breeding and experimental animal facilities tending to improve animal welfare. Immunosupressed mice are susceptible to...

Pasalic, I., Bosnjak, B., Ivetic Tkalcevic, V. et al. 2011. Cage enrichment with paper tissue, but not plastic tunnels, increases variability in mouse model of asthma. Laboratory Animals 45(2), 121-123.

Environmental enrichment, besides having a great impact on animal welfare, can also be a potential variable in experimental research. Thus, we investigated whether enrichment of cages with paper tissues or plastic tunnels affects scientific outcome...

Niu, Y., Zhang, M., Liu, J. 2011. The effect of cage enrichment on fluctuating asymmetry and fecal corticosterone of group-housed laboratory mice. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 740 (Abstract #PS91).

Fluctuating asymmetry (FA) represents small, random deviations from symmetry in bilaterally symmetrical anatomic characteristics, is highly correlated with the amount of stress during development, and thus, is considered as a potential welfare indicator. In the...

Neves, S. 2011. Effects of environmental enrichment on the production of C57BL/6 mice kept in different housing systems. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 788 (Abstract #P201).

The goal of this study was to evaluate the effects of environmental enrichment on the performance of C57BL/6 mice kept in conventional animal facilities (open cage; OC) and individually ventilated caging system (IVC). We analyzed...

Nam-Mi Gross, A., Engela, A. K. J., Würbel, H. 2011. Simply a nest? Effects of different enrichments on stereotypic and anxiety-related behaviour in mice. Applied Animal Behaviour Science 134(3-4), 239-245 .

Improving the home cages of laboratory mice by environmental enrichment has been widely used to reduce cage stereotypies and anxiety-related behaviour in behavioural tests. However, enrichment studies differ substantially in type, complexity and variation of...

Lett, G. S. 2011. The beneficial effects of enrichment on diabetic mice. Enrichment Record 6, 5.

In the last issue of The Enrichment Record, Emily Patterson-Kane and I reported on the work (Cao, Liu et al.) in which investigators demonstrated that even short-term exposure to environmental enrichment (EE) improved resistance to...

Griess, R. S. 2011. Environmental enrichment improves fertility and pup survival. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 16(1), 2-3.

Historically, we have added approximately half a cup of shredded aspen bedding for nest making into each littering cage. This procedure was continued as we looked into additional environmental enrichment. There are many types of...

Gaskill, B., Winnicker, C. L., Garner, J. P. et al. 2011. The naked truth: Breeding performance in outbred and inbred strains of nude mice with and without nesting material. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 741 (Abstract #PS95).

In laboratories, mice are housed at ambient temperatures between 20 to 24 °C, which is below their lower critical temperature of 30 °C, but comfortable for human workers. Thus, mice are thermally stressed, which can...

Gaskill, B., Garner, J. P., Pritchett-Corning, K. 2011. Energy reallocation to breeding performance through improved behavioral thermoregulation. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 771 (Abstract #P120).

Mice are housed at temperatures which increase their basal metabolic rates and impose high energy demands to maintain core temperatures. Thus, energy may be reallocated from other biologic processes to increase heat production. We hypothesized...

Breegi, S. 2011. Evaluation of nesting materials for use in nude mouse colonies. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 782 (Abstract #P171).

Nesting material has been reported to be beneficial to mice by providing environmental enrichment as well as a means of thermoregulation. Cotton nesting material has been reported to cause conjunctivitis in athymic nude mice. We...

Gaskill, B. N., Rohr, S., Lucas, J. R. et al. 2011. Working with what you've got: Changes in thermal preference and behavior in mice with or without nest material. Journal of Thermal Biology. 36(3), 193-199.

In laboratories mice are typically housed at ambient temperatures (Ta) of 20–24 °C, which are below their average preferred Ta of ≈30 °C. Adjusting laboratory Ta is not a solution because preferences differ depending on...

Swetter, B. J., Karpiak, C. P., Cannon, J. T. 2011. Separating the effects of shelter from additional cage enhancements for group-housed BALB/cJ mice. Neuroscience Letters 495(3), 205-209.

Enrichment studies with rodents have demonstrated that cage enhancements can improve animal welfare and performance on common behavioral measures, but few studies have compared more than one type of enrichment or controlled for confounds, and...

Research Department, RSPCA. 2011. Rabbits: Good Practice for Housing and Care (3rd edition).

This report describes what rabbits need in terms of social housing, enclosure size and type, and environmental enrichment. It also describes potential husbandry-related welfare problems and how to resolve them.

Araki, A. 2010. Using environmental enrichment to reduce fighting in mice. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 15(4), 6.

A colony of mice (base strain C57Bl6) was transferred to Oregon State University. Fighting was observed in six cages of males (2 to 5 mice per cage) at cage change, but not during daily checks...

Õkva, K., Nevalainen, T., Mauranen, K. et al. 2010. The effect of three different items of cage furniture on the behaviour of male C57BL/6J mice in the plus-maze test. Animal Welfare 19(4), 401-409.

The aim of this study was to assess the effects of specific regimens of enrichment on the behaviour of C57BL/6J mice in the elevated plus-maze test (EPM). A total of 192 male C57BL/6J mice were...

Williams-Fritze, M. J., Altieri, J. A., Clough, C. et al. 2010. Modification of a dog cage for use as an exercise unit for rabbits. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 703 (Abstract #P70).

The Guide for the Care and Use of Animals and the USDA Animal Welfare Regulations (AWR) outline minimum space requirements for laboratory animals, including rabbits. These documents encourage housing of animals in enclosures that allow...

Tilly, S.-L. C., Dallaire, J., Mason, G. J. 2010. Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment. Animal Behaviour 80(3), 363-373.

For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using environmental enrichment. This resistance to enrichment is often explained via mechanisms that decouple abnormal behaviour from current welfare...

Santos, R. A., Fontes, R. S., Ong, F. M. et al. 2010. Effects of environmental enrichment and housing system on weight gain of C57BL/6 mice. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 712-713 (Abstract #P100).

Our goal was to evaluate the effect of treatment represented by enrichment with cotton balls, and the housing system, by comparing the conventional (open cage) and the ventilated cage (IVC) systems on the weight gain...