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. 
Silva-Almeida, C., Muniz, S. C. A., Jobim, C. M. N. et al. 2024. Perinatal environmental enrichment changes anxiety-like behaviours in mice and produces similar intergenerational benefits in offspring. Behavioural Brain Research 456, 114700.

Environmental enrichment implemented in early life is able to induce long-term changes in gene expression, synaptic function and behavioural responses. In this study, we evaluated the adult behavioural effects of perinatal environment enrichment in male...

Wang, Q., Wang, Y., Tian, Y. et al. 2024. Social environment enrichment alleviates anxiety-like behavior in mice: Involvement of the dopamine system. Behavioural Brain Research 456, 114687.

Rearing environment plays a vital role in maintaining physical and mental health of both animals and humans. Plenty of studies have proved that physical environment enrichment in adolescence has protective effects on emotion, social behavior...

Van Loo, P. L. P., Janssens, M. R. E. 2023. Why all healthy laboratory animals should be rehomed, no matter how small. Animals 13(17), 2727.

This paper explores the ethical imperative of rehoming all healthy animals of sentient species after experiments have finished or when they have become otherwise redundant. We take into account disparate perspectives in animal ethics and...

Harauma, A., Murai, M., Nakamura, I. et al. 2023. Anxiety-like behaviors in artificially reared mice is reduced by contact with foster mothers. Physiology & Behavior 260, 114052.

Experimental systems using animal models are important for nutritional and pharmacological research on newborns and infants. Accordingly, artificial nursing systems for rodents based exclusively on formula are critical to studying nutrient requirements, chemical safety, and...

Carbone, L. 2021. Estimating mouse and rat use in American laboratories by extrapolation from Animal Welfare Act-regulated species. Scientific Reports 11(1), 493.

Alone among Western nations, the United States has a two-tier system for welfare protections for vertebrate animals in research. Because its Animal Welfare Act (AWA) excludes laboratory rats and mice (RM), government veterinarians do not...

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...

Brogan, E., Kirchain, S. 2021. When to wean? A visual guide to Black, White, and Agouti mouse pup growth P14 – P28. Laboratory Animal Science Professional 9(3) (May/June), 46-48.

Laboratory mouse pups are commonly weaned between postnatal day 21–28. Utilization of an exact wean date postpartum is a concrete metric for mouse colony management, but variation can result such as: developmental differences among genetically...

Brajon, S., Morello, G. M., Capas-Peneda, S. et al. 2021. All the pups we cannot see: Cannibalism masks perinatal death in laboratory mouse breeding but infanticide is rare. Animals 11(8), 2327.

Perinatal mortality is a major issue in laboratory mouse breeding. We compared a counting method using daily checks (DAILY_CHECK) with a method combining daily checks with detailed video analyses to detect cannibalisms (VIDEO_TRACK) for estimating...

Grims, C., Jacobson, C., Hedenqvist, P. 2021. Are female mice dehydrated during peak lactation? Effect of water and gel supplement on hydration parameters and water consumption in two strains of mice. Scandinavian Journal of Laboratory Animal Science 47(3), 16-24.

Mice (Mus musculus) have a high basal rate of metabolism which increases during pregnancy and lactation. During peak lactation, water intake amounts to up to 65 % of the bodyweight per day. Providing water in...

Morello, G. M., Hultgren, J., Capas-Peneda, S. et al. 2020. High laboratory mouse pre-weaning mortality associated with litter overlap, advanced dam age, small and large litters. PLOS ONE 15(8): e0236290.

High and variable pre-weaning mortality is a persistent problem in laboratory mouse breeding. Assuming a modest 15% mortality rate across mouse strains, means that approximately 1 million more pups are produced yearly in the EU...

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...

Dewaele, A., Badonnel, K., Persuy, M.-A. et al. 2020. Effect of environmental exposure to a maternally-learned odorant on anxiety-like behaviors at weaning in mice. Animal Cognition 23(5), 881–891.

Early sensory experience, such as exposure to maternal or other environmental factors, is considered to influence neurocognitive development and behaviors. In many species, exposure to odorants during pregnancy or lactation impacts the morpho-functional development of...

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...

Leidinger, C. S., Thöne-Reineke, C., Baumgart, N. et al. 2019. Environmental enrichment prevents pup mortality in laboratory mice. Laboratory Animals 53(1), 53–62.

Early death of mouse pups is a commonly known problem in breeding mice colonies, which is still often regarded as ‘normal’ or is even overlooked due to the counting procedures applied. As reduced breeding performance...

Colby, L. A., Nowland, M. H., Kennedy, L. H. 2019. Clinical Laboratory Animal Medicine: An Introduction (5th ed). Wiley-Blackwell, Ames, IA.

The revised fifth edition of Clinical Laboratory Animal Medicine: An Introduction is an accessible guide to basic information for conducting animal research safely and responsibly. It includes a review of the unique anatomic and physiologic...

Weaver, S. R., Cronick, C. M., Prichard, A. P. et al. 2016. Use of the RatLoft decreases pup mortality in lactating mice. Laboratory Animals 50(5), 370-378.

Lactating mice in laboratory conditions are thought to be under considerable stress. Dams may manifest this stress through a decrease in milk yield and/or increase in infanticide. The purpose of this study was to examine...

Hrapkiewicz, K., Colby, L. A., Denison, P. 2013. Clinical Laboratory Animal Medicine: An Introduction (4th Ed). Wiley-Blackwell, Ames, IA.

Clinical Laboratory Animal Medicine: An Introduction, Fourth Edition offers a user-friendly guide to the unique anatomy and physiology, care, common diseases, and treatment of small mammals and nonhuman primates. Carefully designed for ease of use...

Shair, H. N., Nunez, Y., Osman, M. M. 2012. Enrichment materials do not negatively affect reproductive success and offspring survival and weight in mice. Lab Animal 41(1), 14-19.

Environmental enrichment is designed to improve the overall welfare of laboratory animals, including mice. Few studies have directly assessed the effects of different types of enrichment on mouse offspring survival and growth. The authors examined...

Neves, S. 2011. Effects of environmental enrichment on the production of C57BL/6 mice kept in different housing systems. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 788 (Abstract #P201).

The goal of this study was to evaluate the effects of environmental enrichment on the performance of C57BL/6 mice kept in conventional animal facilities (open cage; OC) and individually ventilated caging system (IVC). We analyzed...

Oteham, C. P. 2010. Effects of specific environmental enrichment contributing to litter size and attrition rate of TRP1/TGfβ transgenic mice in a breeding colony. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 698 (Abstract #P51).

In previous studies of environmental enrichment of mice it has been determined that certain types of mice are affected by manipulation of their living environment. Some have effects on cognitive memory and some affect the...

Howard, B., Nevalainen, T., Perretta, G. (ed). 2010. The COST Manual of Laboratory Animal Care and Use: Refinement, Reduction, and Research (1st Ed). CRC Press, Boca Raton, FL.

COST Action B-24 established four working groups to research and discuss issues relevant to laboratory animal science. These included the housing of animals, environmental needs, refinement of procedures, genetically modified animals, and cost-benefit analysis. Based...

Bayne, K. 2010. Enrichment and behavioral management programs around the world. Enrichment Record 4, 4-7.

To do justice to the diverse approaches to enrichment and behavioral management around the world would entail a discussion beyond the limits of this publication. Therefore, guidelines and regulations in a representative sample of countries...

Taylor K. 2010. Reporting the implementation of the three Rs in European primate and mouse research papers: Are we making progress? Alternatives to Laboratory Animals 38(6), 495-517.

It is now more than 20 years since both Council of Europe Convention ETS123 and EU Directive 86/609/EEC were introduced, to promote the implementation of the Three Rs in animal experimentation and to provide guidance...

Conour, L. A., Murray, K. A., Brown, M. J. 2006. Preparation of animals for research -- Issues to consider for rodents and rabbits. ILAR Journal 47(4), 283-293.

This article provides details to consider when preparing to use animals in biomedical research. The stress of transport and receipt of animals into a new environment mandate the need for a period of stabilization and...

Hutchinson, E., Avery, A., Van de Woude, S. 2005. Environmental enrichment for laboratory rodents. ILAR Journal 46(2), 148-161.

In this article, laws and guidelines relating to rodent enrichment are reviewed, the natural behaviors of select rodent species are discussed, and an overview of widely used types of enrichment in laboratory rodent management is...