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. 
Hartcher, K. M., Tran, M. K. T. N., Wilkinson, S. J., et al. 2015. Plumage damage in free-range laying hens: Behavioural characteristics in the rearing period and the effects of environmental enrichment and beak-trimming. Applied Animal Behaviour Science 164, 64-72.

Severe feather-pecking, whereby birds peck at and pull out the feathers of other birds, is one of the greatest welfare concerns and the most prevalent behavioural problem in laying hens. It can be extremely difficult...

Cloutier, S., Wahl, K. L., Panksepp, J. et al. 2015. Playful handling of laboratory rats is more beneficial when applied before than after routine injections. Applied Animal Behaviour Science 164, 81-90.

The ability of positive affective states to counteract negative states engendered by routine medical procedures remains poorly studied. In laboratory rats, positive affect typically associated with rough-and-tumble play can be induced through human “hand play”...

Bayne, K. A., Beaver, B. V., Mench, J. A. et al. 2015. Laboratory animal behavior. In: Laboratory Animal Medicine, 3rd edition. Fox, J. G., Anderson, L., Otto, G., et al. (eds). Elsevier, Inc., Amsterdam, NL. pp. 1617-1651.

The study of laboratory animal behavior has increased steadily over the last decade, with expanding emphasis on a variety of commonly used species. In the United States, this trend was initially focused on species for...

Perret, A., Henry, L., Coulon, M. et al. 2015. Social visual contact, a primary “drive” for social animals? Animal Cognition 18(3), 657–666.

Social animals are always searching for conspecifics, thereby expressing a genuine “social need”. This need is illustrated by the fact that social isolation can induce isolation syndromes that can be attenuated by devices such as...

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...

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...

Bergman, T. J., Sheehan, M. J. 2013. Social knowledge and signal in primates. American Journal of Primatology 75(7), 683-694.

Primates are notable for having a rich and detailed understanding of their social environment and there has been great interest in the evolution and function of social knowledge in primates. Indeed, primates have been shown...

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...

Cloutier, S., Baker, C., Wahl, K. et al. 2013. Playful handling as social enrichment for individually- and group-housed laboratory rats. Applied Animal Behaviour Science 143(2-4), 85-95.

Social housing is recommended for laboratory rats because they are highly social mammals but research constraints or medical issues often demand individual housing and, when social housing is practiced, it typically involves housing with only...

Warwick, C., Arena, P., Lindley, S. et al. 2013. Assessing reptile welfare using behavioural criteria. In Practice 35(3), 123-131.

While clinical reptile medicine as a science is in its ascendancy among veterinary surgeons and other interested groups, familiarity with the often related issue of reptilian behavioural and psychological health appears less common. Behavioural change...

Sherenco, K. D., Weed, J. L., Tustin, G. W. et al. 2012. Pair formations and management within a captive breeding Aotus colony over a ten year time period. American Journal of Primatology 74(S1), 44. (35th Meeting of the American Society of Primatologists Scientific Program, Abstract #60)

Providing social housing that mimics the species' natural group composition should be an aim for all captive environments. Aotus are nocturnal, monogamist primates whose offspring (both male and female) disperse at sexual maturity, living solitarily...

Hosey, G., Melfi, V. 2012. Human-animal bonds between zoo professionals and the animals in their care. Zoo Biology 31(1), 13-26.

Some human-animal relationships can be so positive that they confer emotional well-being to both partners and can thus be viewed as bonds. In this study, 130 delegates at zoo research and training events completed questionnaires...

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...

Costa, R., Tamascia, M. L., Nogueira, M. D. et al. 2012. Handling of adolescent rats improves learning and memory and decreases anxiety. JAALAS 51(5), 548-553.

Some environmental interventions can result in physiologic and behavioral changes in laboratory animals. In this context, the handling of adolescent or adult rodents has been reported to influence exploratory behavior and emotionality. Here we examined...

Cloutier, S., Panksepp, J., Newberry, R. C. 2012. Playful handling by caretakers reduces fear of humans in the laboratory rat. Applied Animal Behaviour Science 140(3-4), 161-171.

Handling of laboratory rats can increase physiological and emotional stress, leading to a fearful relationship with humans. We hypothesized that the affective quality of handling techniques used during routine care influences the animals' fear of...

Camacho, J. N., Boskovic, S., Moeller, E. 2012. Improved nonhuman primate social housing using visual cues associated for an intensive research study. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 636-637 (Abstract #PS35).

Lean management-based visual tools have been used to improve the quality of animal care associated with a complex research study involving immune-compromised cynomolgus monkeys (M. fascicularis) in various postsurgical recovery states. In order to effectively...

Baker, K. C. 2012. Implementation of pair housing for laboratory primates. American Journal of Primatology 74(S1), 31. (35th Meeting of the American Society of Primatologists Scientific Program, Abstract #20)

There is a general consensus among those studying the welfare of captive primates that social housing is the most effective means for promoting psychological well-being. It is well established that socially-housed rhesus macaques (Macaca mulatta)...

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...

Schapiro, S. J., Bernacky, B. J. 2011. Socialization strategies and disease transmission in captive colonies of nonhuman primates. American Journal of Primatology 74(6), 518-527.

In captive research environments for nonhuman primates (NHP), social housing strategies are often in conflict with protocols designed to minimize disease transmission. This is particularly true in breeding colonies, and is especially relevant when attempting...

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...