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. 
Fares, R., Champéroux, P. 2023. Simultaneous assessment of central nervous and respiratory systems using jacketed telemetry in socially-housed rats: Application of the “3Rs” principles in core battery safety pharmacology studies. Journal of Pharmacological and Toxicological Methods 121, 107268.

Central nervous (CNS) and respiratory systems are routinely investigated in safety pharmacology core battery studies. For small molecules, the assessment of both vital organ systems is frequently done in rats in two distinct studies. With...

Gardhouse, S., Beaufrere, H., Hawkins, M. G. et al. 2023. Evaluation of oral transmucosal administration of pentobarbital for euthanasia of conscious wild birds. Journal of Applied Animal Welfare Science 26(1), 4–14.

This prospective study evaluated oral transmucosal pentobarbital sodium at three doses in 110 wild-caught wild birds requiring euthanasia. Birds received transmucosal pentobarbital at five (430 mg/kg), six (516 mg/kg), and seven times (602 mg/kg) the...

Munro, B. A., Merenick, D. R., Gee, J. M. et al. 2023. Use of loss of righting reflex to assess susceptibility to carbon dioxide gas in three mouse strains. JAALAS 62(6), 553–558.

Exposure to CO2 gas is a common rodent euthanasia method. CO2 activates nociceptors in rats and is painful to humans at concentrations equal to or greater than 32.5% The concentration of CO2 at which rodents...

Santos, R. V., Bhatt, S., Foote, S. et al. 2023. Method of measuring effects of study procedures in single and pair housed New Zealand White rabbits (Oryctolagus cuniculus). Journal of Pharmacological and Toxicological Methods 119, 107204.

Social housing of laboratory rabbits is encouraged and thought to improve animal welfare due to the social nature of this species. However, there is limited published information comparing the physiologic and cardiovascular (CV) effects of...

Schreier, A. L., Readyhough, T. S., Moresco, A. et al. 2023. Social dynamics of a newly integrated bachelor group of Asian elephants (Elephas maximus): Welfare implications. Journal of Applied Animal Welfare Science 26(2), 229–246.

Male associations are a typical component of elephant society, allowing bulls to practice appropriate social behavior. To improve zoo elephant welfare, it is important to provide bulls with social opportunities. In fall 2018, Denver Zoo...

Van Damme, L. G. W., Ampe, B., Delezie, E. et al. 2023. Social behaviour and personality profiles of breeding does housed part-time in group. Applied Animal Behaviour Science 267, 106064.

Housing breeding female rabbits in multi-litter instead of single-litter cages allows for more natural behaviour and social contact with conspecifics. Hierarchy fights among does, however, inhibit uptake on farms. Past focus on high reproductive performances...

Hickman, D. L. 2023. Euthanasia of neonatal rats and mice using carbon monoxide. JAALAS 62(3), 274–278.

Minimization of potential pain and distress of rodents undergoing euthanasia is a touchstone of veterinary clinical medicine. Evaluation of this issue in postweanling rodents has supported revisions to the AVMA (American Veterinary Medical Association) Guidelines...

McNamara, A., Ballantine, A. R., Deuchande, R. et al. 2023. Comparison of fixed and rising displacement rates of CO2 for euthanasia of aged rats. JAALAS 62(5), 453–463.

This study compared euthanasia induced by rising concentrations of CO2 in aged rats (n = 59) using different gas displacement rates. Rats were preimplanted with cardiovascular telemetry devices and had been previously used for short...

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...

Perret-Thiry, C., Raulic, J., Vergneau-Grosset, C. 2022. Evaluation of prolonged immersion in tricaine methanesulfonate for juvenile goldfish (Carassius auratus) euthanasia. Journal of the American Veterinary Medical Association 260(8), 911-915.

OBJECTIVE: Doses of buffered tricaine methanesulfonate (MS-222) up to 1000 mg/L for 15 minutes are reported inefficient to produce euthanasia in goldfish. The goal of this study was to determine if goldfish can be euthanized...

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...

Buckmaster, C. L., Levesque, D., LaFollette, M. et al. 2022. Five hot topics in refinement of nonhuman primate neuroscience research. Laboratory Animal Science Professional 10(1) (January/February), 24-26.

Members of the North American 3Rs Collaborative (NA3RsC) refinement initiative have chosen to summarize developments in five hot topics of interest: 1. Tips for welfare-friendly transport, chairing, and restraint; 2. Guidance on refining food and...

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...

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...