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. 
Lutz, C. K., Williams, P. C., Sharp, R. M. 2014. Abnormal behavior and associated risk factors in captive baboons (Papio hamadryas spp.). American Journal of Primatology 76(4), 355-361.

Abnormal behavior, ranging from motor stereotypies to self‐injurious behavior, has been documented in captive nonhuman primates, with risk factors including nursery rearing, single housing, and veterinary procedures. Much of this research has focused on macaque...

Rommers, J. M., Reuvekamp, B. J. F., Gunnink, H. et al. 2014. Effect of hiding places, straw and territory on aggression in group-housed rabbit does. Applied Animal Behaviour Science 157, 117-126.

Group-housing of rabbit does may be preferred from welfare point of view. However, group-housing causes agonistic behaviour which may cause severe injuries. Severe injuries may be prevented by offering hiding places for attacked does. Providing...

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...

Kalliokoski, O., Teilmann, A. C., Jacoben, K. R. et al. 2014. Do singly housed male mice get lonely? Evidence of depressive states after short-term single housing of BALB/c and C57BL/6 mice. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 597. (Abstract #P184).

Through behavioral and preference studies we know that mice prefer company. Laboratory mice should thus never be housed alone, if a viable option exists. Yet single housing is a fairly common practice, in particular with...

Gaskill, B. 2014. Aggression in laboratory mice: Potential influences and how to manage it. Enrichment Record 18, 22-25.

Aggression is a naturally occurring behavior of mice that can provide benefit to those that display it in the wild. Many factors appear to influence these negative social interactions between mice, making mitigation in the...

Doulames, V., Lee, S., Shea, T. B. 2014. Environmental enrichment and social interaction improve cognitive function and decrease reactive oxidative species in normal adult mice. International Journal of Neuroscience 124(5), 369-376.

Environmental stimulation and increased social interactions stimulate cognitive performance, while decrease in these parameters can exacerbate cognitive decline as a function of illness, injury, or age. We examined the impact of environmental stimulation and social...

Greenberg, G. D., Howerton, C. L., Trainor, B. C. 2014. Fighting in the home cage: Agonistic encounters and effects on neurobiological markers within the social decision-making network of house mice (Mus musculus). Neuroscience Letters 566, 151-155.

Inbred strains of mice, such as C57Bl/6, have become preferred animal models for neurobehavioral studies. A main goal in creating inbred lines is to reduce the effects of individual genetic variation on observed phenotypes. Most...

Grippo, A. J., Ihm, E., Wardwell, J. et al. 2014. The effects of environmental enrichment on depressive and anxiety-relevant behaviors in socially isolated prairie voles. Psychosomatic Medicine 76(4), 277-284.

Social isolation is associated with depression, anxiety and negative health outcomes. Environmental enrichment, including environmental and cognitive stimulation with inanimate objects and opportunities for physical exercise, may be an effective strategy to include in treatment...

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...

Kulesskaya, N., Karpova, N. N., Ma, L. et al. 2014. Mixed housing with DBA/2 mice induces stress in C57BL/6 mice: Implications for interventions based on social enrichment. Frontiers in Behavioral Neuroscience 8, 257.

Several behavioral interventions, based on social enrichment and observational learning are applied in treatment of neuropsychiatric disorders. However, the mechanism of such modulatory effect and the safety of applied methods on individuals involved in social...

Monteiro, B. M., Moreira, F. A., Massensini, A. R. et al. 2014. Enriched environment increases neurogenesis and improves social memory persistence in socially isolated adult mice. Hippocampus 24(2), 239-248.

Social memory consists of the information necessary to identify and recognize cospecifics and is essential to many forms of social interaction. Social memory persistence is strongly modulated by the animal's experiences. We have shown in...

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...

Vaughan, L. M., Dawson, J. S., Porter, P. R. et al. 2014. Castration promotes welfare in group-housed male Swiss outbred mice maintained in educational institutions. JAALAS 53(1), 38-43.

Educational institutions maintain group-housed mice of both sexes for training veterinarians and technicians in husbandry, medication, and sampling procedures. Mice kept in all-male groups may experience poor welfare due to fighting. Castrated mice may be...

Verma, R., Friedler, B. D., Harris, N. M. et al. 2014. Pair housing reverses post-stroke depressive behavior in mice. Behavioural Brain Research 269, 155-163.

Social isolation (SI) has been linked epidemiologically to high rates of morbidity and mortality following stroke. In contrast, strong social support enhances recovery and lowers stroke recurrence. However, the mechanism by which social support influences...

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...

Szendrö, Z., Mikó, A., Odermatt, M. et al. 2013. Comparison of performance and welfare of single-caged and group-housed rabbit does. Animal 7(3), 463-468.

Although rabbit does are generally single housed on rabbit farms worldwide, it has been suggested by some specialists and recommendation of organic rabbit production systems that group housing of does is more comfortable and similar...

Annas, A., Bengtsson, C., Tornqvist, E. 2013. Group housing of male CD1 mice: Reflections from toxicity studies. Laboratory Animals 47(2), 127-129.

Owing to their naturally aggressive behaviour, male mice are often housed individually in toxicity studies. However, several publications advocate group-housing of mice to enable normal social behaviour and interactions between the animals. This refinement project...

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...

Young, L., Lin, R. 2013. Strategies to in increase compatibility among pair-housed rabbits. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 667 (Abstract #P168).

The eighth edition of the Guide for the Care and Use of Laboratory Animals (the Guide) states that appropriate social interaction among members of the same species is essential for normal animal development and wellbeing...

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...

Valuska, A. J., Mench, J. A. 2013. Size does matter: The effect of enclosure size on aggression and affiliation between female New Zealand White rabbits during mixing. Applied Animal Behaviour Science 149(1-4), 72-76.

Social enrichment is increasingly employed to improve the welfare of laboratory animals, including rabbits. However, the high levels of injurious aggression that can occur when unfamiliar adult rabbits are introduced to one another are a...

Fuss, J., Richter, S. H., Steinle, J. et al. 2013. Are you real? Visual stimulation of social housing by mirror image stimulation in single housed mice. Behavioural Brain Research 243, 191-198.

Individual housing of social species is a common phenomenon in laboratory animal facilities. Single housing, however, is known to inflict social deprivation with a number of detrimental consequences. Aiming to improve housing conditions of single...