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. 
Veness, A., Coyle, C., Murphy, S. et al. 2023. Minimising aggression in CD-1 and CD-1 background male mice with different enrichment types. Animal Technology and Welfare 22(1), 74–76.

Cage-mate aggression is a well-known problem that is more prevalent in certain strains of mice and is one of the most common reasons for single housing, increased stress levels, premature death and euthanasia. Numerous methods...

Cavieres, G., Bozinovic, F., Bogdanovich, J. M. et al. 2023. Impact of prolonged chronic social isolation stress on behavior and multifractal complexity of metabolic rate in Octodon degus. Frontiers in Behavioral Neuroscience 17.

Social interaction can improve animal performance through the prevention of stress-related events, the provision of security, and the enhancement of reproductive output and survival. We investigated the effects of prolonged chronic social isolation stress on...

Kitchenham, L., Nazal, B., Adcock, A. et al. 2022. Why does lifelong conventional housing reduce the sociability of female mice? Applied Animal Behaviour Science 246, 105532.

Compared to peers raised in well-resourced, 'enriched' environments (‘EE’), female laboratory mice from conventional barren cages are more aggressive to their cage-mates, and less sociable with familiar non-cage-mates (especially if these too are from conventional...

Denommé, M. R., Mason, G. J. 2022. Social buffering as a tool for improving rodent welfare. JAALAS 61(1), 5-14.

The presence of a conspecific can be calming to some species of animal during stress, a phenomenon known as social buffering. For rodents, social buffering can reduce the perception of and reaction to aversive experiences...

Aldhshan, M. S., Mizuno, T. M. 2022. Effect of environmental enrichment on aggression and the expression of brain-derived neurotrophic factor transcript variants in group-housed male mice. Behavioural Brain Research 433, 113986.

Social and environmental factors influence behavior via modulation of brain physiological functions. Environmental enrichment (EE) is an animal housing technique that provides complex sensory, motor, and social stimulation, leading to modifications in the innate aggressiveness...

McKinney, M. M., Dupont, W. D., Corson, K. J. et al. 2022. Physiologic and behavioral effects in mice anesthetized with isoflurane in a red-tinted or a traditional translucent chamber. JAALAS 61(4), 322-332.

Isoflurane has been characterized as a distressing agent for rodents, causing both physiologic and behavioral effects. Using a "darkened home cage" has been recommended during CO2 administration for rodent euthanasia; this is arguably a similar...

Scariot, P. P., Gobatto, C. A., Polisel, E. E. et al. 2022. Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood. Laboratory Animals 56(4), 344-355.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging...

Hohlbaum, K., Merle, R., Frahm, S. et al. 2022. Effects of separated pair housing of female C57BL/6JRj mice on well-being. Scientific Reports 12(1), 8819.

In laboratory animal facilities, it is a common code of practice to house female mice in groups. However, some experimental conditions require to house them individually, even though social isolation may impair their well-being. Therefore...

Sørensen, D., Cloutier, S., Gaskill, B. (Eds.). 2021. Animal-centric Care and Management - Enhancing Refinement in Biomedical Research. CRC Press, Boca Raton, FL.

The concept of the 3Rs (Refinement, Reduction and Replacement) has been used as a framework for improving the welfare of laboratory animals for the last half century. By establishing an animal-centric view on housing and...

Perea, C., Vázquez-Ágredos, A., Ruiz-Leyva, L. et al. 2021. Caloric restriction in group-housed mice: Littermate and sex influence on behavioral and hormonal data. Frontiers in Veterinary Science 8, 639187.

Much of the research done on aging, oxidative stress, anxiety, and cognitive and social behavior in rodents has focused on caloric restriction (CR). This often involves several days of single housing, which can cause numerous...

Navarro, K. L., Huss, M., Smith, J. C. et al. 2021. Mouse anesthesia: The art and science. ILAR Journal 62(1-2), 238-273.

There is an art and science to performing mouse anesthesia, which is a significant component to animal research. Frequently, anesthesia is one vital step of many over the course of a research project spanning weeks...

Blevins, C. E., Celeste, N. A., Marx, J. O. 2021. Effects of oxygen supplementation on injectable and inhalant anesthesia in C57BL/6 mice. JAALAS 60(3), 289-297.

Oxygen supplementation is rarely considered when anesthetizing laboratory mice, despite reports that mice become profoundly hypoxic under anesthesia. Little is known about the effects of hypoxia on anesthetic performance. This article focuses on the effects...

Yu, J. H., Brown, J., Boisseau, N. et al. 2021. Effects of Lupron and surgical castration on fecal androgen metabolite concentrations and intermale aggression in capybaras (Hydrochoerus hydrochaeris). Zoo Biology 40(2), 135-141.

To curb agonistic interactions in a bachelor group of three male capybaras (Hydrochoerus hydrochaeris), a single dose of leuprolide acetate (Lupron®) was used in an attempt to chemically sterilize the males. Concurrently, fecal androgen metabolite...

Buckinx, A., Van Schuerbeek, A., Bossuyt, J. et al. 2021. Exploring refinement strategies for single housing of male C57BL/6JRj mice: Effect of cage divider on stress-related behavior and hypothalamic-pituitary-adrenal-axis activity. Frontiers in Behavioral Neuroscience 15, 743959.

Introduction: Single housing of laboratory mice is a common practice to meet experimental needs, or to avoid intermale aggression. However, single housing is considered to negatively affect animal welfare and may compromise the scientific validity...

Insel, N., Shambaugh, K. L., Beery, A. K. 2020. Female degus show high sociality but no preference for familiar peers. Behavioural Processes 174, 104102.

Group-living animals vary in social behavior across multiple dimensions, including in the selectivity of social interactions with familiar versus unfamiliar peers. Standardized behavioral tests can be used to tease apart different dimensions of behavior. These...

Peterman, J.L., White, J.D., Calcagno, A. et al. 2020. Prolonged isolation stress accelerates the onset of Alzheimer’s disease-related pathology in 5xFAD mice despite running wheels and environmental enrichment. Behavioural Brain Research 379, 112366.

Research has demonstrated that stress can exacerbate AD pathology in transgenic mouse models of AD. The purpose of the present studies was to extend this work by determining whether a social stressor, isolation stress, would...

Reading, P., Reading, R., Branstone, C. 2020. Mirror, mirror, on the wall. Animal Technology and Welfare 19(1), 98-100.

When mice are grouped together for the first time, it is a novel experience filled with new sights and smells that will stress the animal too much and may cause aggression. By adding a mirror...

Gjendal, K., Ottesen, J. L., Olsson, I. et al. 2020. Effect of repeated exposure to isoflurane on nest building and burrowing in mice. JAALAS 59(1), 30–36.

Nest building and burrowing are highly motivated natural behaviors in rodents, and changes in these behaviors can serve as welfare assessment tools. In this study, we investigated: 1) the limits of agreement between 2 observers...

Hohlbaum, K., Frahm, S., Rex, A. et al. 2020. Social enrichment by separated pair housing of male C57BL/6JRj mice. Scientific Reports 10, 11165.

Laboratory male mice are often housed individually due to aggressive behavior or experimental requirements, though social isolation can cause welfare issues. As a strategy to refine housing of male mice, we introduce the separated pair...

Bailoo, J. D., Voelkl, B., Varholick, J. et al. 2020. Effects of weaning age and housing conditions on phenotypic differences in mice. Scientific Reports 10, 11684.

Poor reproducibility is considered a serious problem in laboratory animal research, with important scientific, economic, and ethical implications. One possible source of conflicting findings in laboratory animal research are environmental differences between animal facilities combined...

Tang, W., Zillmann, U., Sprengel, R. 2020. Alternative anesthesia of neonatal mice for global rAAV delivery in the brain with non-detectable behavioral interference in adults. Frontiers in Behavioral Neuroscience 14, 115.

Viral-transduced gene expression is the current standard for cell-type-specific labeling and cell tacking in experimental neuroscience. To achieve widespread gene expression, a viral delivery method to neonatal rodents was introduced more than two decades ago...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Bodden, C., Wewer, M., Kästner, N. et al. 2021. Not all mice are alike: Mixed-strain housing alters social behaviour. Physiology & Behavior 228, 113220.

The use of millions of mice in scientific studies worldwide emphasises the continuing need for a reduction of sample sizes, however, not at the expense of scientific validity. Split-plot designs have been suggested to enhance...

Theil, J. H., Ahloy-Dallaire, J., Weber, E. M. et al. 2020. The epidemiology of fighting in group-housed laboratory mice. Scientific Reports 10(1), 16649.

Injurious home-cage aggression (fighting) in mice affects both animal welfare and scientific validity. It is arguably the most common potentially preventable morbidity in mouse facilities. Existing literature on mouse aggression almost exclusively examines territorial aggression...

Grífols, R., Zamora, C., Ortega-Saez, I. et al. 2020. Postweaning grouping as a strategy to reduce singly housed male mice. Animals 10(11), 2135.

Rearing laboratory mice in groups is important since social isolation after weaning induces brain alterations, which entails behavioral abnormalities in adulthood. Age is an important factor when grouping males of different litters due to inter-male...