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. 
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...

Lidster, K., Owen, K., Browne, W. J. et al. 2019. Cage aggression in group-housed laboratory male mice: An international data crowdsourcing project. Scientific Reports 9, 15211.

Aggression in group-housed laboratory mice is a serious animal welfare concern. Further understanding of the causes of mouse aggression could have a significant impact on a large number of laboratory animals. The NC3Rs led a...

Zidar, J., Weber, E. M., Ewaldsson, B. et al. 2019. Group and single housing of male mice: Collected experiences from research facilities in Sweden. Animals 9(12), 1010.

The mouse is the most commonly used mammal in scientific research, and housed in research facilities around the world. Mice are a social species, but when housing male mice together in a confined environment in...

Mather, J. A., Carere, C. 2019. Consider the individual: Personality and welfare in invertebrates. In: The Welfare of Invertebrate Animals. Carere, C., Mather, J. (eds), 229-245. Springer, Cham.

Personality, defined as consistent between-individual variation in clusters of behavioral traits independent of factors such as age or sex, emerges in most animal species tested so far. The number of invertebrate species discovered to have...

Gent, T. C., Detotto, C., Vyssotski, A. L. et al. 2018. Epileptiform activity during inert gas euthanasia of mice. PLOS ONE 13(4), e0195872.

Carbon dioxide (CO2) is one of the most commonly used euthanasia agents for mice, yet it is highly aversive and nociceptive. Inert gases are a possible alternative, however there are qualitative reports of seizures resulting...

Dudley, E. S., Boivin, G. P. 2018. Evaluation of a commercially available euthanasia solution as a voluntarily ingested euthanasia agent in laboratory mice. JAALAS 57(1), 30-34.

All currently accepted methods of euthanasia for laboratory mice involve some degree of stress, fear, anxiety, or pain. We evaluated the voluntary oral administration of a euthanasia drug in 99 male and 81 female mice...

Lahger, C., Laska, M. 2018. Behavioral responses of CD-1 mice to conspecific and heterospecific blood odors and to a blood odor component. Physiology & Behavior 184, 2015-210.

The odor of blood may have both aversive and attractive properties for mammals, depending on the species of the odor donor and the species perceiving the odor. To better understand the informational content of blood...

Coke, C., Skoumbourdis, E., Rodgers, J. C. et al. 2018. Blunting/cutting canines of adult male monkeys: A discussion by the Laboratory Animal Refinement & Enrichment Forum. Animal Technology & Welfare 17(2), 105-107.

"When you keep adult Rhesus macaque (Macaca mulatta) males, adult Cynomolgus (Macaca fascicularis) males or adult Vervet males (Chlorocebus pygerythrus), in the same enclosure, is it advisable to have the canines of the males blunted...

Arakawa, H. 2018. Ethological approach to social isolation effects in behavioral studies of laboratory rodents. Behavioural Brain Research 341, 98-108.

The aim of the present review is to discuss how housing conditions affect behavioral performance in laboratory rodents from an ethological view. Commonly used laboratory rodents such as rats and mice, are originally captured animals...

Bailoo, J. D., Murphy, E., Varholick, J. A. et al. 2018. Evaluation of the effects of space allowance on measures of animal welfare in laboratory mice. Scientific Reports 8, 713.

We studied how space allowance affects measures of animal welfare in mice by systematically varying group size and cage type across three levels each in both males and females of two strains of mice (C57BL/6ByJ...

Creamer-Hente, M. A., Lao, F. K., Dragos, Z. P. et al. 2018. Sex- and strain-related differences in the stress response of mice to CO₂ euthanasia. JAALAS 57(5), 513–519.

The 2013 edition of the AVMA Guidelines for the Euthanasia of Animals recommends a 10% to 30% volume displacement rate (VDR) per minute for CO2 euthanasia of rodents. Here we sought to evaluate behavior and...

Blankenberger, W. B., Weber, E. M., Chu, D. K. et al. 2018. Breaking up is hard to do: Does splitting cages of mice reduce aggression? Applied Animal Behaviour Science 206, 94-101.

Injurious aggression in group housed male laboratory mice is a common welfare issue that can also negatively affect study outcomes. Often, one mouse in the cage appears unwounded, and the current standard practice is to...

Bastian, M. L., Glendinning, D. R., Reddy, A. J. et al. 2018. Nest location preferences in zoo-housed orangutans. Applied Animal Behaviour Science 207, 123-128.

Nest building is an advanced and complex activity that wild orangutans engage in, yet they do so on a daily basis and with potential safety consequences. Like their wild counterparts, zoo-housed orangutans also make nests...

Rytlewski, J. D., Childress, P. J., Scofield, D. C. et al. 2018. Cohousing male mice with and without segmental bone defects. Comparative Medicine 68(2), 131–138.

Spaceflight results in bone loss like that associated with osteoporosis or decreased weight-bearing (for example, high-energy trauma such as explosive injuries and automobile accidents). Thus, the unique spaceflight laboratory on the International Space Station presents...

Allen, C., Duggan, L., Fox, M. et al. 2018. Attempting enrichment harmonization across multiple sites and embracing our differences. Laboratory Animal Science Professional 5(4) (December), 48-51.

A glabal enrichment committee incorporates active members from each of the company’s 6 sites and works towards harmonization of enrichment practices. One of the hot topics is attempting to standardize mouse enrichment and social housing...

Menke, C., Pisharath, H., Goodchild, L. et al. 2018. The use of enrichment to reduce fighting in male laboratory mice. Laboratory Animal Science Professional 6(1) (March), 44-45.

Typical husbandry solutions for aggressive mice are individual housing or separation into smaller groups. Individual housing is stressful to mice, while separation into smaller groups can increase housing-related costs for the researchers. To alleviate these...

Hawkins, P., McBride, A., Paiba, G. et al. 2018. Report of the 2017 RSPCA/UFAW Rodent and Rabbit Welfare Group meeting. Animal Technology and Welfare 17(2), 75-83. [Meeting Report]

The RSPCA/UFAW Rodent (and now Rabbit) Welfare Group held a one-day meeting on 14 November 2017 in Weybridge, UK. The first session addressed meeting animals' needs and aiming for a 'good life', with the needs...

Marquardt, N., Feja, M., Hünigen, H. et al. 2018. Euthanasia of laboratory mice: Are isoflurane and sevoflurane real alternatives to carbon dioxide? PLOS ONE 13(9), e0203793.

In the European Union (EU) millions of laboratory mice are used and killed for experimental and other scientific purposes each year. Although controversially discussed, the use of carbon dioxide (CO2) is still permitted for killing...

Weber, E. M., Dallaire, J. A., Gaskill, B. N. et al. 2017. Aggression in group-housed laboratory mice: Why can’t we solve the problem? Lab Animal 46(4), 157-161.

Group housing is highly important for social animals. However, it can also give rise to aggression, one of the most serious welfare concerns in laboratory mouse husbandry. Severe fighting can lead to pain, injury and...

Gaskill, B. N., Stottler, A. M., Garner, J. P. et al. 2017. The effect of early life experience, environment, and genetic factors on spontaneous home-cage aggression-related wounding in male C57BL/6 mice. Lab Animal 46(4), 176-184.

Aggression is a major welfare issue in mice, particularly when mice unfamiliar to each other are first placed in cages, as happens on receipt from a vendor, and following cage cleaning. Injuries from aggression are...

Kappel, S., Hawkins, P., Mendl, M. 2017. To group or not to group? Good practice for housing male laboratory mice. Animals 7(12), 88.

It is widely recommended to group-house male laboratory mice because they are ‘social animals’, but male mice do not naturally share territories and aggression can be a serious welfare problem. Even without aggression, not all...

Boivin, G. P., Hickman, D. L., Creamer-Hente, M. A. et al. 2017. Review of CO2 as a euthanasia agent for laboratory rats and mice. JAALAS 56(5), 491-499.

Selecting an appropriate, effective euthanasia agent is controversial. Several recent publications provide clarity on the use of CO2 in laboratory rats and mice. This review examines previous studies on CO2 euthanasia and presents the current...

de Souza Dyer, C., Brice, A. K., Marx, J. O. 2017. Intraperitoneal administration of ethanol as a means of euthanasia for neonatal mice (Mus musculus). JAALAS 56(3), 299-306.

The humane euthanasia of animals in research is of paramount importance. Neonatal mice frequently respond differently to euthanasia agents when compared with adults. The AVMA's Guidelines for the Euthanasia of Animals includes intraperitoneal injection of...

Boivin, G. P., Bottomley, M. A., Schiml, P. A. et al. 2017. Physiologic, behavioral, and histologic responses to various euthanasia methods in C57BL/6NTac male mice. JAALAS 56(1), 69-78.

Rodent euthanasia using exposure to increasing concentrations of CO2 has come under scrutiny due to concerns of potential pain during the euthanasia process. Alternatives to CO2, such as isoflurane and barbiturates, have been proposed as...