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. 
Lidfors, L., Wichman, A., Ewaldsson, B. et al. 2014. Enriched cages for groups of laboratory male rats and their effects on behaviour, weight gain and adrenal glands. Laboratory Animals 48, 36-49.

We investigated if there were any negative effects on the behaviour and physiology of rats housed in groups of five in two types of enriched cages and compared them with paired-housed rats housed in traditional...

Hori, M., Yamada, K., Ohnishi, J. et al. 2014. Tickling during adolescence alters fear-related and cognitive behaviors in rats after prolonged isolation. Physiology & Behavior 131, 62-67.

Social interactions during adolescence are important especially for neuronal development and behavior. We recently showed that positive emotions induced by repeated tickling could modulate fear-related behaviors and sympatho-adrenal stress responses. In the present study, we...

Krügel, U., Fischer, J., Bauer, K. et al. 2014. The impact of social isolation on immunological parameters in rats. Archives of Toxicology 88(3), 853-855.

In various toxicological studies, single housing of rodents is preferred to standardize for regulatory purposes. However, housing conditions can have severe, often underestimated, impact on results in toxicological examinations. As different husbandry conditions have been...

Sharp, J., Azar, T., Lawson, D. 2014. Effects of a complex housing environment on heart rate and blood pressure of rats at rest and after stressful challenges. JAALAS 53(1), 52-60.

Housing enrichment for rodents continues to be a discussion topic within the animal care community. The objective of this study was to determine the extent to which a complex housing environment affects heart rate, blood...

Turner, P. V., Sunohara-Neilson, J., Ovari, J. et al. 2014. Effects of single compared with pair housing on hypothalamic-pituitary-adrenal axis activation and low-dose heroin place conditioning in adult male Sprague-Dawley rats. JAALAS 53(2), 161-167.

Whether social isolation of adult rats under standard laboratory conditions produces significant long-term alterations in behavior and physiology is unclear. In the present study, male Sprague–Dawley rats were singly or paired-housed for 10 wk. During...

Gaillard, C., Meagher, R. K., von Keyserlingk, M. A. et al. 2014. Social housing improves dairy calves' performance in two cognitive tests. PLOS ONE 9(2), e90205.

Early social housing is known to benefit cognitive development in laboratory animals. Pre-weaned dairy calves are typically separated from their dam immediately after birth and housed alone, but no work to date has addressed the...

Rushen, J., de Passillé, A. M., Appleby, M. C. et al. 2014. Alone or together: A risk assessment approach to group housing. In: Dilemmas in Animal Welfare. Appleby, M. C., Weary, D. M., Sandøe, P. (eds), 169-187. CAB International, Oxfordshire, UK.

The question of whether it is better to house animals in groups rather than alone deals with the unresolved issues at the heart of animal welfare. In particular, we need to be able to rank...

Abou-Ismail, U. A., Darwish, R. A., Ramadan, S. G. A. 2014. Should cages of laboratory rats be enriched physically or socially? Global Veterinaria 13(4), 570-582.

Experiments of environmental enrichment usually compare between group-housed rats in enriched and unenriched cages or between group-housed rats in enriched cages and single-housed rats in unenriched cages. This bias is mainly to maximize the chance...

Reinhardt, V. (ed.) 2013. Compassion Makes a Difference - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume III. Animal Welfare Institute, Washington, DC.

This is the third volume of discussions that took place on the Laboratory Animal Refinement & Enrichment Forum (LAREF). This forum is dedicated to the exchange of personal experiences of refining the conditions under which...

Winnicker, C. 2013. Challenges and opportunities of implementing EU standards for social housing of rodents. Enrichment Record 15, 3-4.

The EU Directive on the protection of animals used for scientific purposes specifically states: Animals, except those which are naturally solitary, shall be socially housed in stable groups of compatible individuals. Even in cases where...

Gonzaleza, M., Averosa, X., de Herediaa, I. B. et al. 2013. The effect of social buffering on fear responses in sheep (Ovis aries). Applied Animal Behaviour Science 149(1-4), 13-20.

Fear in farm animals has been extensively studied because of its close relation to animal welfare. Numerous studies have categorized the behavioral responses of animals to stimuli that can elicit a fear reaction under social...

Rault, J.-L. 2012. Friends with benefits: Social support and its relevance for farm animal welfare. Applied Animal Behaviour Science 136(1), 1-14.

Despite growing interest in promoting positive welfare, rather than just alleviating poor welfare, potential measures of good welfare, and means to provide it, have remained elusive. In humans social support improves stress-coping abilities, health, and...

Gudsnuk, K., Champagne, F. A. 2012. Epigenetic influence of stress and social environment. ILAR Journal 53(3-4), 279-288.

Animal models of early-life stress and variation in social experience across the lifespan have contributed significantly to our understanding of the environmental regulation of the developing brain. Plasticity in neurobiological pathways regulating stress responsivity, cognition...

de Paula Vieira, A., Weary, D. M., de Passillé, A. M. 2012. Effects of the early social environment on behavioral responses of dairy calves to novel events. Journal of Dairy Science 95(9), 5149-5155.

Providing young animals the opportunity to engage in more complex social interactions is hypothesized to improve their capacity to cope with changing environments. To test the effects of the early social environment on the behavioral...

Duve, L. R., Jensen, M. B. 2012. Social behavior of young dairy calves housed with limited or full social contact with a peer. Journal of Dairy Science 95(10), 5936-5945.

This study compared the effect of individual and pair housing and age at pair housing on the social behavior of young dairy calves. Twenty-seven pairs of calves were reared from birth until 6 wk either...

Azar, T., Sharp, J., Lawson, D. 2011. Heart rates of male and female Sprague-Dawley and spontaneously hypertensive rats housed singly or in groups. JAALAS 50(2), 75-84.

This study was conducted to confirm our previous reports that group housing lowered basal heart rate and various evoked heart-rate responses in Sprague-Dawley male and female rats and to extend these observations to spontaneously hypertensive...

Nakayasu, T., Kato, K. 2011. Is full physical contact necessary for buffering effects of pair housing on social stress in rats? Behavioural Processes 86(2), 230-235.

Our previous study showed that pair housing with a familiar male prevented an increase in anxiety caused by social defeat in male rats. The present study attempted to identify the aspects of social interactions with...

Baran, S. W., Froberg-Fejko, K., Lecker, J. et al. 2010. Post-surgical environmental enrichment in rodents. Enrichment Record 3, 4-6.

Environmental enrichment is a key component of rodent animal welfare since it influences the animal’s overall well-being, provides opportunities for activity, and encourages rodent appropriate behaviors. Many aspects of rodent enrichment have received a significant...

Turner, P. V., Ovari, J., Pinelli, C. et al. 2010. Long-term effects of housing and enrichment on affective behavior and responsiveness of Sprague-Dawley rats. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 658-659 (Abstract #PS12).

Most rodent studies evaluate different caging paradigms over short periods of time, which may not be realistic for typical colony settings. Inappropriate housing may lead to boredom, aggression, stereotypies, and altered metabolism, which in turn...

Villeneuve, L., Méthot, H., Cinq-Mars, D. et al. 2009. Effect of individual or paired housing during post-weaning on feed intake, growth rate and behaviour of lambs. Small Ruminant Research 85(2-3), 99-104.

The aim of this study was to compare the behaviour and weight gain of weaned lambs penned either in pairs or alone, with visual and tactile contacts between pens. A 2 × 2 factorial experiment...

Nowak, R., Porter, R. H., Blache, D. et al. 2008. Behavior and welfare of the sheep. In: The Welfare of Sheep. Dwyer, C. M. (ed). Springer, New York, NY.

The most important features of the behaviour of sheep are their marked sociality and the bond formation between mother and young. Sheep show a strong need to stay with their group (or subgroup for some...

Gonder, J. C., Laber, K. 2007. A renewed look at laboratory rodent housing and management. ILAR Journal 48(1), 29-46.

In this article, recent publications are examined to determine the potential impact of new scientific evidence on current practices for the housing and care of laboratory rodents. The discussion points out recent advances in technology...

Van Loo, P., Skoumbourdis, E., Reinhardt, V. 2006. Postsurgical pairing: A discussion by the Refinement & Enrichment Forum. Animal Technology and Welfare 5(1), 17-19.

Our experience-based discussion suggests that social animals benefit from compatible companionship during post-operative recovery. The traditional practice of keeping animals alone in an unfamiliar environment after surgery increases the subjects surgery-associated stress. Providing a familiar...

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...

Sharp, J. L., Zammit, T., Azar, T. A. et al. 2003. Stress-like responses to common procedures in individually and group-housed female rats. Contemporary Topics in Laboratory Animal Science 42(1), 9-18.

Mean resting HR values in the mornings prior to human contact were significantly (P