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. 
Kammertoens, T., Jeuthe, S., Baranzke, H. et al. 2021. Breeding and maintenance of immunodeficient mouse lines under SPF conditions—A call for individualized severity analyses and approval procedures. Animals 11(6), 1789.

In the EU, the breeding of genetically modified laboratory animals is, by definition, an animal experiment if the offspring may experience pain, suffering, or harm. In order to determine the actual burden of genetically modified...

van der Geest, J. N., Spoor, M., Frens, M. A. 2021. Environmental enrichment improves vestibular oculomotor learning in mice. Frontiers in Behavioral Neuroscience 15, 676416.

We assessed the behavioral effects of environmental enrichment on contrast sensitivity, reflexive eye movements and on oculomotor learning in mice that were housed in an enriched environment for a period of 3 weeks. Research has...

Moody, C. M., Paterson, E. A. Leroux-Petersen, D. et al. 2021. Using paper nest pucks to prevent barbering in C57BL/6 mice. JAALAS 60(2), 133-138.

Little research has been conducted to examine the influence of various methods of providing nest materials—such as dispersing them, providing them as single units, or clustering them—on the behavior and welfare of group-housed mice. In...

Edwards, J., Olson, B., Marks, D.L. 2021. Constructing and programming a cost-effective murine running wheel with digital revolution counter. Lab Animal 50, 202-204.

Voluntary wheel running is a valuable metabolic intervention and well-established measure of physical activity in preclinical rodent models. Herein, we describe detailed assembly instructions and provide necessary resources for researchers to build their own running...

Lambert, K. 2021. DIY: Acacia gum sealed paper straws. Laboratory Animal Science Professional 9(3) (May/June), 37.

This DIY snack is great for NHP and can be customized in a variety of ways.

Lambert, K. 2021. DIY: Dehydrated watermelon training chips. Laboratory Animal Science Professional 9(4) (July/August), 48.

This simple DIY training treat is great for NHP, swine, rabbits, rodents, and dogs. Note that dehydrated watermelon may resemble muscle tissue!

Windsor, Z. 2021. Refinements in head plate mouse nesting: Using composite nests to enhance welfare. Animal Technology and Welfare 20(2), 135-141.

When given the opportunity, mice will choose to build nests using multiple different materials. Studies indicate that providing mice with choices which mimic the natural environment allows laboratory mice to build the best quality nests...

Peploe, J., MacAulay, C. 2021. Laboratory primate enrichment ideas. Animal Technology and Welfare 20(2), 177-183.

There are several items we often use in animal facilities that when finished with are thrown away. However, many of these items come in packaging that can be recycled as enrichment for our animals, particularly...

Burn, C. C., Popat, R. 2021. A tunnel is not enough: Mice benefit from in-cage provision of a communal shelter as well as a handling tunnel. Animal Technology and Welfare 20(3), 203-210.

Mouse shelters can provide mice with security, help them thermoregulate, offer darkness to prevent damage to their eyes and enable climbing and gnawing opportunities. For laboratory mice, there is a vast array of commercially available...

Obermueller, B., Castellani, C., Till, H. et al. 2021. An examination of nest-building behaviour using five different nesting materials in C57BL/6J and BALB/c mice. Animal Welfare 30(4), 467-477.

The aim of our study was to assess the nest-building behaviour of two mouse (Mus musculus) strains using different nesting materials and examine possible sex- and housing-specific effects. Adult mice of two strains (C57BL/6J; n...

Rodriguez-Sanchez, R., Barnaby, E., Améndola, L. et al. 2021. Voluntary oral ingestion of a sedative prior to euthanasia with CO2: Behavioural responses of mice. Animals 11(10), 2879.

Laboratory mice are commonly euthanised with carbon dioxide (CO2); however, there is ample evidence that this gas is aversive. Previous work suggests that sedation achieved via injection with benzodiazepines prior to CO2 administration could reduce...

Minie, V. A., Petric, R., Ramos-Maciel, S. et al. 2021. Enriched laboratory housing increases sensitivity to social stress in female California mice (Peromyscus californicus). Applied Animal Behaviour Science 241, 105381.

Domesticated mice and rats have shown to be powerful model systems for biomedical research, but there are cases in which the biology of species is a poor match for the hypotheses under study. The California...

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...

Campbell, D. L. M., Lee, C. 2021. A perspective on strategic enrichment for brain development: Is this the key to animal happiness? Frontiers in Veterinary Science 8, 720422.

Livestock animals are sentient beings with cognitive and emotional capacities and their brain development, similar to humans and other animal species, is affected by their surrounding environmental conditions. Current intensive production systems, through the restrictions...

Brunt, M. W., Améndola, L., Weary, D. M. 2021. Attitudes of laboratory animal professionals and researchers towards carbon dioxide euthanasia for rodents and perceived barriers to change. Laboratory Animals 55(6), 531-539.

Evidence indicates that carbon dioxide (CO2) induces negative affective states (including anxiety, fear and distress) in laboratory rodents, but many countries still accept it for euthanasia. Alternative methods (e.g. inhalant anaesthetic) may represent a refinement...

Lambert, K. 2021. DIY: Acacia gum hanging saucer. Laboratory Animal Science Professional 9(5) (September/October), 50.

This article describes the ingredients, supplies, and directions to make this DIY hanging item, which is great for NHP and swine.

Lambert, K. 2021. DIY: Busy boxes. Laboratory Animal Science Professional 9(6) (November/December), 32.

This article describes the ingredients and directions to make this simple DIY destructible enrichment for NHP and swine.

Garcia, T., Brown, C., Margolies, D. et al. 2021. Grinding on a last nerve: Attempting to curb food grinding in mice. Laboratory Animal Science Professional 9(6) (November/December), 34-36.

Food grinding, or chewing food without ingestion, is a topic of interest in the laboratory animal community. In addition to increased effort needed to deal with this excess waste and provide suitable microenvironment for animals...

Ratuski, A. S., Makowska, I. J., Dvorack, K. R. et al. 2021. Using approach latency and anticipatory behaviour to assess whether voluntary playpen access is rewarding to laboratory mice. Scientific Reports 11(1), 18683.

Laboratory mice are typically housed in “shoebox" cages that limit the expression of natural behaviours. Temporary access to more complex environments (playpens) may improve their welfare. We aimed to assess if access to playpens is...

Mertens, S., Gass, P., Palme, R. et al. 2020. Effect of a partial cage dividing enrichment on aggression-associated parameters in group-housed male C57BL/6NCrl mice. Applied Animal Behaviour Science 224, 104939.

Group-housing is highly important for social animals. Group-housing of male mice in captivity though often leads to aggression with partially disastrous consequences for the animals as well as for the quality of experimental data. In...

McAllister, B. B., Thackray, S. E., Garciá de la Orta, B. K. et al. 2020. Effects of enriched housing on the neuronal morphology of mice that lack zinc transporter 3 (ZnT3) and vesicular zinc. Behavioural Brain Research 379, 112336.

In the central nervous system, certain neurons store zinc within the synaptic vesicles of their axon terminals. This vesicular zinc can then be released in an activity-dependent fashion as an intercellular signal. The functions of...

Oralman, T. 2020. Confronting crunching: A refinement for the care of mice with the desire to crunch. Animal Technology and Welfare 19(1), 89-91.

‘Crunching’ is the term often used to describe the abnormal behaviour of mice that habitually crunch their pelleted diet, causing substrate levels to rise as the crumbs settle on the cage floor ultimately burying the...

Blok, J., Black, D. A., Petersen, J. et al. 2020. Environmental enrichment rescues visually-mediated behavior in Ten-m3 knockout mice during an early critical period. Frontiers in Behavioral Neuroscience 14, 22.

Environmental enrichment (EE) has been shown to promote neural plasticity. Its capacity to induce functional repair in models which exhibit profound sensory deficits due to aberrant axonal guidance has not been well-characterized. Ten-m3 knockout (KO)...

Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss...

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...