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. 
Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Esparza, K. 2023, August. Moving away from soiled bedding sentinels—The (R)evolution in rodent health screening. Animal Technology and Welfare 22(2), 158–160.

Traditional health monitoring methods consisted of Soiled Bedding Sentinels (SBS (i.e. animals exposed to dirty bedding from colony animals)), which require the euthanasia of SBS. Numerous studies have demonstrated that SBS may not accurately represent...

Marin, N., Moragon, A., Gil, D. et al. 2023. Acclimation and blood sampling: Effects on stress markers in C57Bl/6J mice. Animals 13(18), 2816.

Blood sampling in rodents is common practice in scientific studies. Some of the refined methods widely used are the puncture of the saphenous vein or tail vein, or even tail docking. The handling needs of...

Stevens, C., Hammonds, T., Hinchcliffe, J. et al. 2023. Report of the 2022 RSPCA/UFAW Rodent Welfare Group Meeting. Animal Technology and Welfare 22(2), 91–100.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 29 years, so that its members can discuss current welfare research, exchange views on welfare issues and share experiences of...

Hickman, D. L. 2022. Minimal exposure times for irreversible euthanasia with carbon dioxide in mice and rats. JAALAS 61(3), 283-286.

When using an anesthetic overdose to euthanize laboratory rodents, a secondary method of euthanasia is recommended to ensure that the apparent death is irreversible. This secondary method usually is accomplished through the collection of tissues...

Ahrens Kress, A. P., Zhang, Y., Kaiser-Vry, A. R. et al. 2022. A Comparison of blood collection techniques in mice and their effects on welfare. JAALAS 61(3), 287-295.

Multiple methods are used to collect blood from mice; these methods have different effects on animal welfare. This study compared blood collection from facial, chin, and saphenous locations with regard to various parameters, including the...

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...

Clarkson, J. M., Martin, J. E., McKeegan, D. E. F. 2022. A review of methods used to kill laboratory rodents: Issues and opportunities. Laboratory Animals 56(5), 419-436.

Rodents are the most widely used species for scientific purposes. A critical pre-requisite of their use, based on utilitarian ethical reasoning, is the provision of a humane death when necessary for scientific or welfare grounds...

Müller, K., Lengheimer, T., Kral-Pointner, J. B. et al. 2022. Exposure to soiled bedding reduces abnormal repetitive behaviors in mice. Frontiers in Behavioral Neuroscience 16, 1062864.

Hygiene management protocols in laboratory mouse husbandries worldwide most commonly employ soiled bedding-exposed sentinel mice to monitor the occurrence of infections in mouse colonies. Using this approach, sentinel mice repeatedly receive a mixture of used...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

Hepps Keeney, C., Harrison, T. M. 2022. Euthanasia complications in non-domestic species. Journal of Zoological and Botanical Gardens 3(4), 616–623.

There are very few studies describing euthanasia complications in non-domestic species. The goal of this study was to survey veterinarians to determine what complications may commonly occur during the euthanasia of non-domestic species. An online...

Hickman, D. L. 2021. Wellbeing of mice euthanized with carbon dioxide in their home cage as compared with an induction chamber. JAALAS 60(1), 72-76.

The AVMA Guidelines on Euthanasia state that, to decrease potential distress of animals, the home cage should be used for the euthanasia of mice. The current study evaluated this recommendation by comparing behavioral and physiologic...

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...

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...

Prior, H., Blunt, H., Crossman, L. et al. 2021. Refining procedures within regulatory toxicology studies: Improving animal welfare and data. Animals 11(11), 3057.

During the development of potential new medicines or agrochemicals, an assessment of the safety profile to humans and environmental species is conducted using a range of different in silico and in vitro techniques in conjunction...

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...

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...

Nøgaard, S. A., Sand, F. W., Sørensen, D. B. et al. 2020. Four- and six-hour urinary albumin excretion is a valuable alternative to 24-h urinary albumin excretion in male db/db mice. Animal Welfare 29(2), 143-149.

In mouse (Mus musculus) models of diabetic nephropathy (DN), one of the most important read-outs is the 24-h urinary albumin excretion (UAE). The 24-h urine collection is usually performed by single housing mice in metabolic...

Whittaker, A. L., Barker, T. H. 2020. The impact of common recovery blood sampling methods, in mice (Mus musculus), on well-being and sample quality: A systematic review. Animals 10(6), 989.

Blood sampling is often performed in laboratory mice. Sampling techniques have the potential to cause pain, distress and impact on lifetime cumulative experience. In spite of institutions commonly providing guidance to researchers on these methods...

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...

Lawrence, M. J., Raby, G. D., Teffer, A. K. et al. 2020. Best practices for non-lethal blood sampling of fish via the caudal vasculature. Journal of Fish Biology 97(1), 4–15.

Blood sampling through the caudal vasculature is a widely used technique in fish biology for investigating organismal health and physiology. In live fishes, it can provide a quick, easy and relatively non‐invasive method for obtaining...

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...

Shomer, N. H., Allen-Worthington, K. H., Hickman, D. L. et al. 2020. Review of rodent euthanasia methods. JAALAS 59(3), 242–253.

The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the...