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. 
Hickman D. L. 2018. Interpreting neuroendocrine hormones, corticosterone, and blood glucose to assess the wellbeing of anesthetized rats during euthanasia. JAALAS 57(6), 725–728.

Current recommendations for assessing animal wellbeing during euthanasia suggest that measuring neuroendocrine hormones—such as ACTH, noradrenaline, and adrenaline—is preferable to measuring corticosterone and blood glucose because of the sensitivity of neuroendocrine hormones to the acute...

Hickman D. L. 2018. Home cage compared with induction chamber for euthanasia of laboratory rats. JAALAS 57(6), 729–733.

This study compared behavioral and physiologic changes in Sprague–Dawley and Brown Norway rats that were euthanized by using a 30% volume displacement rate of CO2 in either their home cage or an induction chamber; rats...

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...

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...

Toyoshima, M., Yamada, K., Sugita, M. et al. 2018. Social enrichment improves social recognition memory in male rats. Animal Cognition 21(3), 345–351.

The social environment is thought to have a strong impact on cognitive functions. In the present study, we investigated whether social enrichment could affect rats’ memory ability using the “Different Objects Task (DOT),” in which...

Redfern, W. S., Tse, K., Grant, C. et al. 2017. Automated recording of home cage activity and temperature of individual rats housed in social groups: The Rodent Big Brother project. PLOS ONE 12(9), e0181068.

Measuring the activity and temperature of rats is commonly required in biomedical research. Conventional approaches necessitate single housing, which affects their behavior and wellbeing. We have used a subcutaneous radiofrequency identification (RFID) transponder to measure...

Barker, T. H., George, R. P., Howarth, G. S. et al. 2017. Assessment of housing density, space allocation and social hierarchy of laboratory rats on behavioural measures of welfare. PLOS ONE 12(9), e0185135.

Minimum space allowances for laboratory rats are legislated based on weight and stocking rates, with the understanding that increased housing density encourages crowding stress. However, there is little evidence for these recommendations, especially when considering...

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...

Pinelli, C., Leri, F., Turner, P. 2017. Long term physiologic and behavioural effects of housing density and environmental resource provision for adult male and female Sprague Dawley rats. Animals 7(6), 44.

There is considerable interest in refining laboratory rodent environments to promote animal well-being, as well as research reproducibility. Few studies have evaluated the long term impact of enhancing rodent environments with resources and additional cagemates...

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...

Ross, A. P., Norvelle, A., Choi, D. C. et al. 2017. Social housing and social isolation: Impact on stress indices and energy balance in male and female Syrian hamsters (Mesocricetus auratus). Physiology & Behavior 177, 264-269.

Although Syrian hamsters are thought to be naturally solitary, recent evidence from our laboratory demonstrates that hamsters may actually prefer social contact. Hamsters increase their preference for a location associated with an agonistic encounter regardless...

Holgate, J. Y., Garcia, H., Chatterjee, S. et al. 2017. Social and environmental enrichment has different effects on ethanol and sucrose consumption in mice. Brain and Behavior 7(8), e00767.

Factors leading to the harmful consumption of substances, like alcohol and sucrose, involve a complex interaction of genes and the environment. While we cannot control the genes we inherit, we can modify our environment. Understanding...

Silva de Souza Matos, L., Palme, R., Silva Vasconcellos, A. 2017. Behavioural and hormonal effects of member replacement in captive groups of blue-fronted amazon parrots (Amazona aestiva). Behavioural Processes 138, 160-169.

Social species in captivity may face allostatic overload due to artificial grouping and other social constraints. In rescue centres, groups of psittacines are constantly mixed due to the arrival and/or release of individuals; this procedure...

Pasquarelli, N., Voehringer, P., Henke, J. et al. 2017. Effect of a change in housing conditions on body weight, behavior and brain neurotransmitters in male C57BL/6J mice. Behavioural Brain Research 333, 35-42.

The development of modern housing regimes such as individually ventilated cage (IVC) systems has become very popular and attractive in order to reduce spreading of pathogenic organisms and to lower the risk to develop a...

Guedes, S. R., Valentim, A. M., Antunes, L. M. 2017. Mice aversion to sevoflurane, isoflurane and carbon dioxide using an approach-avoidance task. Applied Animal Behaviour Science 189, 91-97.

Euthanasia of laboratory animals is one of the main concerns for animal welfare, especially the use of carbon dioxide (CO2) which has been described to induce aversive-like behaviours. In order to refine mass euthanasia in...