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. 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...

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...

Truelove, M. A., Smith, P. O., Martin, A. L. et al. 2022. Predictors of long-term social compatibility in rhesus macaques (Macaca mulatta) housed in research settings. Journal of Applied Animal Welfare Science 25(4), 418-426.

Social housing improves the well-being of monkeys in research settings; however, little is known about factors influencing the long‐term stability of established, full-contact pairs. Archival data were examined to determine whether sex, age, weight, duration...

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...

Hohlbaum, K., Merle, R., Frahm, S. et al. 2022. Effects of separated pair housing of female C57BL/6JRj mice on well-being. Scientific Reports 12(1), 8819.

In laboratory animal facilities, it is a common code of practice to house female mice in groups. However, some experimental conditions require to house them individually, even though social isolation may impair their well-being. Therefore...

Charbonneau, J. A., Amaral, D. G. Bliss-Moreau, E. 2022. Social housing status impacts rhesus monkeys’ affective responding in classic threat processing tasks. Scientific Reports 12(1), 4140.

Individuals’ social contexts are broadly recognized to impact both their psychology and neurobiology. These effects are observed in people and in nonhuman animals who are the subjects for comparative and translational science. The social contexts...

Wotton, S., Grist, A., O’Callaghan, M. et al. 2021. Head-only stunning of turkeys Part 2: Subjective and objective assessment of the application of AC and DC waveforms. Animals 11(2), 286.

Electrical stunning is likely to remain an important stunning method for turkeys at slaughter. The purpose of this study is to understand the application of various waveforms of alternating current (AC) and pulsed direct currents...

Rox, A., van Vliet, A. H., Langermans, J. A. M. et al. 2021. A stepwise male introduction procedure to prevent inbreeding in naturalistic macaque breeding groups. Animals 11(2), 545.

Male introductions into captive primate breeding groups can be risky and unsuccessful. However, they are necessary to prevent inbreeding in naturalistic breeding groups. The procedure used to introduce new individuals may affect the success and...

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...

Bailey, K. L., Young, L. A., Long, C. E. et al. 2021. Use of introduction enclosures to integrate multimale cohorts into groups of female rhesus macaques (Macaca mulatta). JAALAS 60(1), 103-111.

Integrating animals into a new group is a challenge for both free-ranging and captive adult male rhesus monkeys (Macaca mulatta), and for females in groups receiving new males. To ensure the genetic viability of the...

Bader, L., Janavaris, M., Coleman, K. et al. 2021. It takes a village: A case study in improving animal welfare with a team approach. Laboratory Animal Science Professional 9(1) (January/February), 38-40.

There are many factors that need to be considered when caring for groups of nonhuman primates (NHPs) in research, including clinical, behavioral, and scientific issues. Otherwise, there is the potential that decisions are made without...

Prior, H., Holbrook, M. 2021. Strategies to encourage the adoption of social housing during cardiovascular telemetry recordings in non-rodents. Journal of Pharmacological and Toxicological Methods 108, 106959.

The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) is working with industry to promote social housing during cardiovascular telemetry recordings within non-rodent safety pharmacology and toxicology studies. Following surveys...

Cowl, V. B., Walker, S. L., Shultz, S. 2021. Reproductive males are effective at managing conflict in captive Sulawesi crested macaques (Macaca nigra). American Journal of Primatology 83(7), e23266.

Group size, density, and composition significantly influence the expression of agonism and, as demography is frequently manipulated in captivity, natural mechanisms of conflict management may be disrupted. Here, we examine how changes to the social...

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...

Bailey, K. L., Bloomsmith, M. A., Michopoulos, V. et al. 2021. Influence of female coalitionary aggressive behavior on the success of male introductions to female groups of rhesus macaques (Macaca Mulatta). Applied Animal Behaviour Science 237, 105293.

Migration patterns of wild rhesus macaque males are often mimicked in captivity by introducing unfamiliar males to female groups every few years. This strategy prevents inbreeding and has been shown to encourage group stability once...

Perea, C., Vázquez-Ágredos, A., Ruiz-Leyva, L. et al. 2021. Caloric restriction in group-housed mice: Littermate and sex influence on behavioral and hormonal data. Frontiers in Veterinary Science 8, 639187.

Much of the research done on aging, oxidative stress, anxiety, and cognitive and social behavior in rodents has focused on caloric restriction (CR). This often involves several days of single housing, which can cause numerous...

Stow, R., Kendrick, J., Ibbotson, N. et al. 2021. A new group housing approach for non-human primate metabolism studies. Journal of Pharmacological and Toxicological Methods 107, 106947.

Understanding the absorption, distribution, metabolism and excretion (ADME) of candidate drugs in preclinical species is an integral part of the safety and efficacy evaluation in drug development. For this purpose, the housing of single animals...

Beisner, B. A., Remillard, C. M., Moss,S. et al. 2021. Factors influencing the success of male introductions into groups of female rhesus macaques: Introduction technique, male characteristics and female behavior. American Journal of Primatology 83(9), e23314.

In captive populations of rhesus macaques, novel adult males are commonly introduced to female groups every few years to prevent inbreeding, which mimics male dispersal in wild macaque populations. However, introducing adult males is challenging...

Kimm, S., Rauterberg, S. L., Bill, J. et al. 2021. Use of space, active and resting behaviour in fattening rabbits (Oryctolagus cuniculus) housed in a combi park system: A case study. Animal Welfare 30(4), 493-506.

In this case study, a housing system for rabbits (Oryctolagus cuniculus) was developed, complying with the new German Welfare Regulation, and evaluated on-farm with regard to the rabbits' behaviour during four fattening periods. The housing...

Pomerantz, O., Capitanio, J. P. 2021. Temperament predicts the quality of social interactions in captive female rhesus macaques (Macaca mulatta). Animals 11(8), 2452.

Previous reports suggest that female macaques with greater similarity in emotionality and nervous temperament, as evaluated in a well-established BioBehavioral Assessment (BBA) at the California National Primate Research Center, were more likely to form successful...

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...

Balasubramaniam, K. N., Beisner, B. A., McCowan, B. et al. 2021. Female social structure influences, and is influenced by, male introduction and integration success among captive rhesus macaques (Macaca mulatta). Behaviour 158(11), 1007–1042.

Animal social structure is influenced by multiple socioecological factors. Of these, the links between changes to group demography through the arrival of new individuals and residents' social structure remain unclear. Across seven groups of captive...

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...

Orient, E., Guillén-Salazar, F. 2021. The effects of alpha male removal on the social behavior of a group of olive baboons (Papio anubis). Journal of Applied Animal Welfare Science 24(4), 424-433.

In captivity, the managers of primate populations have removed individuals from their groups for medical and social reasons, but there has been little documentation regarding the consequences of this extraction on the sociality of the...

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...