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. 
Bwye, P. 2021. Social distancing is over: A pygmy slow loris trio housed together at Bristol Zoo Gardens. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 48(3), 15-17.

After the loss of one of our breeding males and the export of loris offspring, in 2021 our off-show female loris was solitary. During this time, we noticed a number of changes in this female...

Wilkin, M. M., Menard, J. L. 2020. Social housing ameliorates the enduring effects of intermittent physical stress during mid-adolescence. Physiology & Behavior 214, 112750.

Our prior work showed that exposing single housed rats to intermittent physical stress (IPS) in mid-adolescence (PD35-46) led to increased risk-taking/decreased anxiety behaviour in adulthood, as indexed by their greater willingness to explore the open-arms...

Crailsheim, D., Stüger, H., P., Kalcher-Sommersguter, E. et al. 2020. Early life experience and alterations of group composition shape the social grooming networks of former pet and entertainment chimpanzees (Pan troglodytes). PLOS ONE 15(1), e0226947.

The long-term effects of early life adversities on social capacities have been documented in humans and wild-caught former laboratory chimpanzees (Pan troglodytes). However, former pet and entertainment chimpanzees have received little attention to date. This...

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...

Piller, A., Bergmann, S., Schwarzer, A. et al. 2020. Validation of histological and visual scoring systems for foot-pad dermatitis in broiler chickens. Animal Welfare 29(2), 185-196.

In this study, an appropriate visual scoring system for foot-pad dermatitis was validated, considering the histologically measured depth of the inflammation zone and the histopathological grade (no lesion, mild lesion, ulcer). The aim being to...

Jones, P., Tahamtani, F., Pedersen, I. et al. 2020. The productivity and financial impacts of eight types of environmental enrichment for broiler chickens. Animals 10(3), 378.

Reduced mobility in broilers can contribute to leg health problems. Environmental enrichment has been suggested as one approach to combat this through stimulating increased physical activity. Past studies have tested the effect of environmental enrichments...

Baker, S. L., Robison, C. I., Karcher, D. M. et al. 2020. Keel impacts and associated behaviors in laying hens. Applied Animal Behaviour Science 222, 104886.

Factors contributing to the development of keel bone damage are not well understood. This study aimed to identify behaviors and cage structures associated with acceleration events experienced by individual hens at their keels as the...

Thøfner, I., Hougen, H. P., Villa, C. et al. 2020. Pathological characterization of keel bone fractures in laying hens does not support external trauma as the underlying cause. PLOS ONE 15(3), e0229735.

Keel bone fractures in laying hens have been described with increasing prevalence from several countries over the last twenty years and are considered one of the greatest welfare problems to the layer industry. In Denmark...

Armstrong, E. A., Rufener, C., Toscano, M. J. et al. 2020. Keel bone fractures induce a depressive-like state in laying hens. Scientific Reports 10(1), 3007.

In commercial flocks of laying hens, keel bone fractures (KBFs) are prevalent and associated with behavioural indicators of pain. However, whether their impact is severe enough to induce a depressive-like state of chronic stress is...

Harrup, A. J., Rooney, N. 2020. Current welfare state of pet guinea pigs in the UK. Veterinary Record 186(9), 282.

Little research has been carried out into how guinea pigs are cared for in the UK, and information regarding potential welfare issues is sparse. This study was designed to examine the five welfare needs, collecting...

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...

Veasey, J. 2020. Assessing the psychological priorities for optimising captive Asian elephant (Elephas maximus) welfare. Animals 10(1), 39.

The welfare status of elephants under human care has been a contentious issue for two decades or more in numerous western countries. Much effort has gone into assessing the welfare of captive elephants at individual...

Wendler, P., Ertl, N., Flügger, M. et al. 2020. Influencing factors on the foot health of captive Asian elephants (Elephas maximus) in European zoos. Zoo Biology 39(2), 109-120.

Pathological lesions of feet occur frequently in captive elephant populations. To improve foot health, it is important to identify risk factors associated with such pathologies. Several previous studies have analyzed potentially influencing factors but were...

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...

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...

Hambrecht, S., Oerke, A.‐K., Heistermann, M. et al. 2020. Diurnal variation of salivary cortisol in captive African elephants (Loxodonta africana) under routine management conditions and in relation to a translocation event. Zoo Biology 39(3), 186–196.

The present study assessed the diurnal variation in salivary cortisol in captive African elephants during routine management (baseline) and in relation to a potential stressor (translocation) to evaluate to what extent acute stress may affect...

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...

Allanic, M., Hayashi, M., Matsuzawa, T., 2020. Investigating the function of mutual grooming in captive bonobos (Pan paniscus) and Chimpanzees (Pan troglodytes). Folia Primatologica 91, 481-494.

Social grooming is often exchanged between individuals in many primate species. Rates of bidirectional (or simultaneous mutual) grooming vary across primate species, and its function is not yet fully understood. For example, mutual grooming is...

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.

Larson, M. A. 2020. Alternatives to shipping live mice. Laboratory Animal Science Professional 8(5) (September/October), 52-54.

Many in the lab animal field are familiar with shipping animals from vendor to investigator, from investigator to vendor, and from investigator to investigator. Sharing mouse models represents being good stewards of our animal resources...

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...

Evison, E., McKenzie, A., Holmes, L. 2020. Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus). Zoo Biology 39(6), 397-404.

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge...

Glaeser, S. S., Edwards, K. L., Wielebnowski, N. et al. 2020. Effects of physiological changes and social life events on adrenal glucocorticoid activity in female zoo-housed Asian elephants (Elephas maximus). PLOS ONE 15(11), e0241910.

Ensuring good health and welfare is an increasingly important consideration for conservation of endangered species and includes breeding of individuals managed under human care. Understanding how factors in the captive environment affect individual animal wellbeing...