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. 
Stuckey, J. E., Makhija, S. D., Reimer, D. C. et al. 2023. Effects of different grades of carbon dioxide on euthanasia of mice (Mus musculus). JAALAS 62(5), 430–437.

Carbon dioxide (CO2) is a conditionally acceptable method for mouse euthanasia, according to the American Veterinary Medical Association Guidelines for the Euthanasia of Animals. In a 2012 Office of Laboratory Animal Welfare (OLAW) webinar, representatives...

Tirado-Muñiz, N., Spangler, T. L., Van Rooyen, H. et al. 2023. Evaluation of cage mate–induced postsurgical trauma in mice. JAALAS 62(2), 170–178.

Although mice are social animals, individual housing is sometimes requested after surgery. We questioned whether pair-housing mice after surgery resulted in greater trauma to the surgical site as compared with single housing. We further evaluated...

Butcher, G., Davidson, A., Sloanc, A. et al. 2021. An apparatus for automatically training and collecting individualized behavioral data with socially housed rodents. Journal of Neuroscience Methods 365, 109387.

Background: Conventional methods for individually housing, training, and testing rodents in behavioral assays can impose constraints that may limit some kinds of experimental external validity, preempt environmental enrichment, impose heavy experimenter time burdens that limit...

Stryjek, R., Modlinska, K. 2022. Pre-exposure via wire-mesh partition reduces intraspecific aggression in male, wild-type Norway rats. Animal Welfare 31(2), 175-186.

There are instances when animals are introduced and expected to live alongside unfamiliar conspecifics within zoos, laboratories and wildlife sanctuaries. These pairings of unfamiliar animals may result in stress, trauma, or even death, in addition...

Kitchenham, L., Nazal, B., Adcock, A. et al. 2022. Why does lifelong conventional housing reduce the sociability of female mice? Applied Animal Behaviour Science 246, 105532.

Compared to peers raised in well-resourced, 'enriched' environments (‘EE’), female laboratory mice from conventional barren cages are more aggressive to their cage-mates, and less sociable with familiar non-cage-mates (especially if these too are from conventional...

Denommé, M. R., Mason, G. J. 2022. Social buffering as a tool for improving rodent welfare. JAALAS 61(1), 5-14.

The presence of a conspecific can be calming to some species of animal during stress, a phenomenon known as social buffering. For rodents, social buffering can reduce the perception of and reaction to aversive experiences...

Wooddell, L. J., Beisner, B. A., Nathman, A. C. et al. 2022. Sex differences in hierarchical stability in a formation of a mixed-sex group of rhesus macaques. JAALAS 61(1), 67-74.

Forming groups of captive rhesus macaques (Macaca mulatta) is a common management practice. New formations of unfamiliar macaques can be costly, with high levels of trauma, particularly as intense aggression is used to establish a...

Hickman, D. L. 2022. Evaluation of carbon dioxide euthanasia of female Sprague Dawley rats alone or with unfamiliar conspecifics. JAALAS 61(2), 195-200.

Most studies evaluating methods of euthanasia to date have focused on the euthanasia of individual animals. However, larger chambers are commonly used to euthanize multiple cages of animals at once. This study evaluated the use...

Berro, L. F., Pareek, T., Reeves-Darby, J. A. et al. 2022. Influence of pair-housing on sleep parameters evaluated with actigraphy in female rhesus monkeys. JAALAS 61(2), 165-172.

Rhesus monkeys are naturally social animals, and behavioral management strategies have focused on promoting pairhousing in laboratory settings as an alternative to individual or group housing. In humans, co-sleeping can have a major impact on...

Kezar, S. M., Baker, K. C., Russell-Lodrigue, K. E. et al. 2022. Single-dose diazepam administration improves pairing success of unfamiliar adult male rhesus macaques (Macaca mulatta). JAALAS 61(2), 173-180.

Social housing is one of the best forms of environmental enhancement for nonhuman primates, and current research into pair compatibility and introduction techniques focuses on improving safety and outcome. The gradual steps method (GS), which...

Stammen, R. L., Cohen, J. K., Connor-Stroud, F. R. et al. 2022. Enhancing animal welfare by providing custom caging space for nonhuman primates. Laboratory Animal Science Professional 10(1) (January/February), 20-23.

The YNPRC recently renovated two NHP housing areas with a novel facility design and equipped with a customized caging system that offers additional outdoor access, socialization, and enrichment opportunities for NHPs assigned to infectious disease...

Tomeczko, S. 2022. Interpreting macaque facial expressions and body behavior in preparation for social housing. Laboratory Animal Science Professional 10(1) (January/February), 62-63.

This article will help those who are new to working with non-human primates. Interpreting macaque facial expressions and body behavior is important for beginning the process of pair housing two animals.

Stull, C., Heagerty, A., Coleman, K. 2022. Video conference technology as a tool for pair introduction in rhesus macaques. Animals 12(14), 1783.

Pair housing is known to promote welfare for macaques in captivity. However, finding compatible partners can be challenging, particularly when animals are not located near one another. Because macaques show interest in videos of conspecifics...

Aldhshan, M. S., Mizuno, T. M. 2022. Effect of environmental enrichment on aggression and the expression of brain-derived neurotrophic factor transcript variants in group-housed male mice. Behavioural Brain Research 433, 113986.

Social and environmental factors influence behavior via modulation of brain physiological functions. Environmental enrichment (EE) is an animal housing technique that provides complex sensory, motor, and social stimulation, leading to modifications in the innate aggressiveness...

Lee, V. E., Arnott, G., Turner, S. P. 2022. Social behavior in farm animals: Applying fundamental theory to improve animal welfare. Frontiers in Veterinary Science 9, 932217.

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important...

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...

Li, W., Yan, C., Descovich, K. et al. 2022. The effects of preslaughter electrical stunning on serum cortisol and meat quality parameters of a slow-growing Chinese chicken breed. Animals 12(20), 2866.

Electrical stunning is widely utilized prior to a neck cut to induce unconsciousness in order to improve animal welfare and slaughter efficiency in the broiler production industry. However, slaughter without stunning is still very commonly...

Nuber, M., Gonzalez-Uarquin, F., Neufurth, M. et al. 2022. Development of a 3D simulator for training the mouse in utero electroporation. PLOS ONE 17(12), e0279004.

In utero electroporation (IUE) requires high-level training in microinjection through the mouse uterine wall into the lateral ventricle of the mouse brain. Training for IUE is currently being performed in live mice as no artificial...

Pellis, S. M., Pellis, V. C., Ham, J. R. et al. 2022. The rough-and-tumble play of rats as a natural behavior suitable for studying the social brain. Frontiers in Behavioral Neuroscience 16, 1033999.

Laboratory rats have been an important model species with which to study the neurobiology of rough-and-tumble play (RTP). RTP in rats involves competition to gain access to the partner’s nape of the neck, which is...

Brough, D. W., Murkin, J. T., Amos, H. E. et al. 2022. Comparing variability in measurement of subcutaneous tumors in mice using 3D thermal imaging and calipers. Comparative Medicine 72(6), 364–375.

Repeatable tumor measurements are key to accurately assessing tumor growth and treatment efficacy. A preliminary study that we conducted showed that a novel 3D and thermal imaging system (3D-TI) for measuring subcutaneous tumors in rodents...