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. 
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...

Johnston, J. R., Meeker, T. L., Ramsey, J. K. et al. 2020. Utility of automated feeding data to detect social instability in a captive breeding colony of rhesus macaques (Macaca mulatta): A case study of intrafamily aggression. JAALAS 59(1), 46–57.

Some captive breeding colonies of rhesus macaques live in large outdoor multimale, multifemale social groups. These groups are composed of several matrilineal families, governed by a clear female dominance hierarchy. Aggression within the same or...

Mishra, P. S., Pal, A., Velankar, A. D. et al. 2020. Does rank rule? Rank-related grooming patterns in Nicobar long-tailed macaques Macaca fascicularis umbrosus. Primates 61(3), 443–453.

Primates maintain social bonds with specific individuals in the group by directing grooming toward them. Social grooming is often targeted toward individuals with whom the most benefits can be exchanged, which are usually the high-ranking...

Stocker, M. Loretto, M.-C., Sterck, E. H. M. et al. 2020. Cooperation with closely bonded individuals reduces cortisol levels in long-tailed macaques. Royal Society Open Science 7(5), 7191056.

Many animal species cooperate with conspecifics in various social contexts. While ultimate causes of cooperation are being studied extensively, its proximate causes, particularly endocrine mechanisms, have received comparatively little attention. Here, we present a study...

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...

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...

LaFleur, R. A., Williams-Fritze, M. J. 2020. Now hear this: Caring for chinchillas in research. Laboratory Animal Science Professional 8(5) (September/October), 8-12.

This article describes the authors’ experience with the housing, social housing, husbandry, handling, and environmental enrichment of chinchillas in laboratories.

Begni, V., Sanson, A., Pfeiffer, N. et al. 2020. Social isolation in rats: Effects on animal welfare and molecular markers for neuroplasticity. PLOS ONE 15(10), e0240439.

Early life stress compromises brain development and can contribute to the development of mental illnesses. A common animal model used to study different facets of psychiatric disorders is social isolation from early life on. In...

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...

Cassidy, L. C., Hannibal, D. L., Semple, S. et al. 2020. Improved behavioral indices of welfare in continuous compared to intermittent pair-housing in adult female rhesus macaques (Macaca mulatta). American Journal of Primatology 82(10), e23189.

Limiting opportunities for captive nonhuman primates (NHPs) to express species-specific social behaviors may disrupt the adaptive drive for social companionship and may lead to increases in coping behaviors and inactivity. While captive NHPs show improved...

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...

Borland, J. M., Kim, E., Swanson, S. P. et al. 2020. Effect of aggressive experience in female Syrian hamsters on glutamate receptor expression in the nucleus accumbens. Frontiers in Behavioral Neuroscience 14, 583395.

Our social relationships determine our health and well-being. In rodent models, there is now strong support for the rewarding properties of aggressive or assertive behaviors to be critical for the expression and development of adaptive...

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...

Newman, R., McKeown, S., Power, T. et al. 2020. Introducing three new males into a captive lion-tailed macaque (Macaca silenus) group. Journal of Zoo and Aquarium Research 8(3), 212-217.

The introduction of an unfamiliar animal to a new individual or group can be highly stressful for any animal. Various studies have tried to determine the best method for introducing unfamiliar animals to each other...

Lefebvre, E., Granon, S., Chauveau, F. 2020. Social context increases ultrasonic vocalizations during restraint in adult mice. Animal Cognition 23(2), 351–359.

Adult mice emit many ultrasonic vocalizations (USVs) during social interaction tasks, but only a few studies have yet reported USVs in stressed adult mice. Our aim was to study which experimental conditions favor USV emission...

Beisner, B. A., Wooddell, L. J., Hannibal, D. L. et al. 2019. High rates of aggression do not predict rates of trauma in captive groups of macaques. Applied Animal Behaviour Science 212, 82-89.

Socially inflicted traumas are a major concern for the management of captive groups of rhesus macaques. Rhesus macaques are the most commonly used nonhuman primate in biomedical research, and social housing is optimal for promoting...

Melotti, L., Kästner, N., Eick, A. K. et al. 2019. Can live with ‘em, can live without ‘em: Pair housed male C57BL/6J mice show low aggression and increasing sociopositive interactions with age, but can adapt to single housing if separated. Applied Animal Behaviour Science 214, 79-88.

The basic question as to whether male laboratory mice should be singly or group housed represents a major animal welfare concern within current laboratory animal legislation and husbandry. To better understand the behavioural and physiological...

Berg, M. R., Heagerty, A., Coleman, K. 2019. Oxytocin and pair compatibility in adult male rhesus macaques (Macaca mulatta). American Journal of Primatology 81(8), e23031.

Pair housing is considered one of the best ways of promoting psychological wellbeing for caged macaques. However, incompatible partnerships can result in stress or aggression. Though previous studies have analyzed the role of variables such...

Nip, E., Adcock, A., Nazal, B. et al. 2019. Why are enriched mice nice? Investigating how environmental enrichment reduces agonism in female C57BL/6, DBA/2, and BALB/c mice. Applied Animal Behaviour Science 217, 73-82.

Compared to female mice raised in large, environmentally enriched (EE) cages, those from “shoebox” non-enriched (NE) cages demonstrate more stereotypic behaviour (SB) and depressive-like effects (i.e. learned helplessness; and inactive-but-awake behaviour [IBA], where a mouse...

Brajon, S., Morello, G. M., Teixeira, M. S. et al. 2019. Social environment as a cause of litter loss in laboratory mouse: A behavioural study. Applied Animal Behaviour Science 218, 104827.

Perinatal mortality is a widespread problem in laboratory mouse breeding and is often manifested by the loss of the entire litter within the first days of life. High mortality is an animal health and welfare...

Liang, F., Yang, S., Zhang, Y. et al. 2019. Social housing promotes cognitive function through enhancing synaptic plasticity in APP/PS1 mice. Behavioural Brain Research 368, 111910.

Previous studies have shown that loneliness increases the risk of AD (Alzheimer’s disease) onset, while active and frequent social housing delays the onset of cognitive impairment. The mechanism of how this occurs remains unclear. In...

Hurtado-Parrado, C., Cardona-Zea, Á, Arias-Higuera, M. et al. 2019. Behavioral patterns of laboratory Mongolian gerbils by sex and housing condition: A case study with an emphasis on sleeping patterns. Journal of Veterinary Behavior 30, 69-79.

The behavioral patterns of Mongolian gerbils (Meriones unguiculatus) housed individually and in same-sex groups (siblings) were characterized. Gerbils were continuously video-recorded 24 hours (day 1) and 120 hours (day 5) after housing conditions were established...

Azkona, G., Caballero, J. M. 2019. Implementing strategies to reduce singly housed male mice. Laboratory Animals 53(5), 508–510.

There are different husbandry situations that lead to social isolation of male mice. Besides legal considerations, single housing has a negative impact on behavioural and molecular studies. We have implemented two strategies, the ‘companion mouse’...

Sherrill, C., Kavanagh, K. 2019. Fight Club: Using housing conditions to curb male cage aggression. Laboratory Animal Science Professional 7(1) (March), 38-40.

Those who have worked with C57BL/6 males know how aggressive they can be towards their cage mates. We poured over academic journals, reading every article we could find regarding male home cage aggression. Three articles...