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. 
McMillan, F. D. (ed). 2019. Mental Health and Well-being in Animals (2nd ed). CABI, Wallingford, UK.

This second edition is fully revised, expanded, and comprehensively updated with the most current knowledge about the full array of mental health issues seen in animals. Written by key opinion leaders, internationally-recognized experts and specialists...

Aujnaraina, A. B., Luoa, O. D., Taylor, N. et al. 2018. Effects of exercise and enrichment on behaviour in CD-1 mice. Behavioural Brain Research 342, 43-50.

A host of scholarly work has characterized the positive effects of exercise and environmental enrichment on behaviour and cognition in animal studies. The purpose of this study was to investigate the uptake and longitudinal impact...

Bailoo, J. D., Murphy, E., Varholick, J. A. et al. 2018. Evaluation of the effects of space allowance on measures of animal welfare in laboratory mice. Scientific Reports 8, 713.

We studied how space allowance affects measures of animal welfare in mice by systematically varying group size and cage type across three levels each in both males and females of two strains of mice (C57BL/6ByJ...

Barker, T. H., George, R. P., Howarth, G. S. et al. 2017. Assessment of housing density, space allocation and social hierarchy of laboratory rats on behavioural measures of welfare. PLOS ONE 12(9), e0185135.

Minimum space allowances for laboratory rats are legislated based on weight and stocking rates, with the understanding that increased housing density encourages crowding stress. However, there is little evidence for these recommendations, especially when considering...

Pinelli, C., Leri, F., Turner, P. 2017. Long term physiologic and behavioural effects of housing density and environmental resource provision for adult male and female Sprague Dawley rats. Animals 7(6), 44.

There is considerable interest in refining laboratory rodent environments to promote animal well-being, as well as research reproducibility. Few studies have evaluated the long term impact of enhancing rodent environments with resources and additional cagemates...

Polissidis, A., Zelelak, S., Nikita, M. et al. 2017. Assessing the exploratory and anxiety-related behaviors of mice. Do different caging systems affect the outcome of behavioral tests? Physiology & Behavior 177, 68-73.

Ample studies have shown that housing can affect the health, welfare and behavior of mice and therefore, the outcomes of certain experiments. The aim of this study was to investigate if three widely used housing...

Barker, T. H., Bobrovskaya, L., Howarth, G. S. et al. 2017. Female rats display fewer optimistic responses in a judgment bias test in the absence of a physiological stress response. Physiology & Behavior 173, 124-131.

Metabolic cages are a type of housing used in biomedical research. Metabolic cage housing has been demonstrated to elicit behavioural and physiological changes in rodents housed within them. The nature of this effect has been...

Kleefeld, S., Bannerton, K., Kelly, J.2017. Effect of moderate environmental enrichment on commonly used behavioural tests in rats. Animal Technology and Welfare 16(1), 75-76.

The environment that laboratory animals are housed in should reflect their natural habitats in a manner that can satisfy their innate physiological and behavioural needs. This includes nest building, hiding, exploring and foraging. Providing environmental...

Makowska, I. J., Weary, D. M. 2016. Differences in anticipatory behaviour between rats (Rattus norvegicus) housed in standard versus semi-naturalistic laboratory environments. PLOS ONE 11(1), e0147595.

Laboratory rats are usually kept in relatively small cages, but research has shown that they prefer larger and more complex environments. The physiological, neurological and health effects of standard laboratory housing are well established, but...

Heyse, N. C., Brenes, J. C., Schwarting, R. K. W. 2015. Exercise reward induces appetitive 50-kHz calls in rats. Physiology & Behavior 147, 131-140.

Rats express affective states by visible behaviors (like approach or flight) and through different kinds of ultrasonic vocalizations (USV). 50-kHz calls are thought to reflect positive affective states since they occur during rewarding situations like...

Bartal, I. B.-A., Rodgers, D. A., Sarria, M. S. et al. 2014. Pro-social behavior in rats is modulated by social experience. eLife 3, e01385.

In mammals, helping is preferentially provided to members of one’s own group. Yet, it remains unclear how social experience shapes pro-social motivation. We found that rats helped trapped strangers by releasing them from a restrainer...

Jones, C. E., Riha, P. D., Gore, A. C. et al. 2014. Social transmission of Pavlovian fear: Fear-conditioning by-proxy in related female rats. Animal Cognition 17(3), 827–834.

Pairing a previously neutral conditioned stimulus (CS; e.g., a tone) to an aversive unconditioned stimulus (US; e.g., a foot-shock) leads to associative learning such that the tone alone will elicit a conditioned response (e.g., freezing)...

Makowska, I. J., Weary, D. M. 2013. Assessing the emotions of laboratory rats. Applied Animal Behaviour Science 148, 1-12.

Rats are one of the most commonly used species in research, and decades of testing have yielded a large amount of information pertaining to their experience of emotion. The aim of this review is to...

Whittaker, A. L., Howarth, G. S., Hickman, D. L. 2012. Effects of space allocation and housing density on measures of wellbeing in laboratory mice: A review. Laboratory Animals 46(1), 3-13.

In the majority of countries where there are legislative requirements pertaining to the use of animals in research, figures are quoted for minimum cage sizes or space allocation to be provided per animal. These figures...

Gewin, V. 2011. Rats free each other from cages. Nature News.

Following a two-week introduction period, pairs of rats were put inside an arena. One was trapped inside a central restrainer, while the other roamed free in the larger space. By day six or seven, on...

Brydges, N. M., Leach, M., Nicol, K. et al. 2011. Environmental enrichment induces optimistic cognitive bias in rats. Animal Behaviour 81(1), 169-175.

People's affective or emotional state can alter their cognitive processing, biasing interpretation of ambiguous stimuli. Those in a more positive state interpret such stimuli in a more optimistic manner than those in a negative state...

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...

Li, W. J., Yu, H., Yang, J. M. et al. 2010. Anxiolytic effect of music exposure on BDNFMet/Met transgenic mice. Brain Research 1347, 71-79.

Brain-derived neurotrophic factor (BDNF) has been reported to play important roles in the modulation of anxiety, mood stabilizers, and pathophysiology of affective disorders. Recently, a single nucleotide polymorphism (SNP) in the BDNF gene (Val66Met) has...

Onbasilar, E. E., Onbasilar, Í. 2007. Effect of cage density and sex on growth, food utilization and some stress parameters of young rabbits. Scandinavian Journal of Laboratory Animal Science 34(3),189-195.

The aim of the experiment was to study the effects of cage density (1, 3 and 5 rabbits per cage) and sex (male and female) on stress parameters of young rabbits. A total of 90...

Conour, L. A., Murray, K. A., Brown, M. J. 2006. Preparation of animals for research -- Issues to consider for rodents and rabbits. ILAR Journal 47(4), 283-293.

This article provides details to consider when preparing to use animals in biomedical research. The stress of transport and receipt of animals into a new environment mandate the need for a period of stabilization and...

Smith, A. L., Mabus, S. L., Muir, C. et al. 2005. Effects of housing density and cage floor space on three strains of young adult inbred mice. Comparative Medicine 55(4), 368-376.

Some recommendations in the Guide for the Care and Use of Laboratory Animals (the Guide) are based on best professional judgment. Our current efforts are directed toward replacement with data-driven standards. We demonstrated earlier that...

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...

Hirsjärvi, P. A., Väliaho, T. 1995. Gentled and nonhandled Wistar rats in a mildly novel open-field situation. Scandinavian Journal of Laboratory Animal Science 22(3), 265-269.

Open-field behaviour of individually gentled and nonhandled adult male Wistar rats was studied in a mildly novel test situation. The gentled rats were more active and showed fewer signs of fear on the first trial...

Hall, C. S., Ballachey, E. L. 1932. A study of the rat's behavior in a field: A contribution to method in comparative psychology. University of California Publications in Psychology 6, 1-12.

THE OPEN-FIELD (OF) TEST, originally developed by Hall (Hall & Ballachey, 1932), is one of the most widely used methods in the study of emotionality in rodents. The test is conducted in an enclosed open...