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. 
Wittek, L., Touma, C., Nitezki, T. et al. 2023. Reduction in cold stress in an innovative metabolic cage housing system increases animal welfare in laboratory mice. Animals 13(18), 2866.

Housing in metabolic cages can induce a pronounced stress response. Metabolic cage systems imply housing mice on metal wire mesh for the collection of urine and feces in addition to monitoring food and water intake...

Benato, L., Murrell, J., Rooney, N. 2023. Determining a cut-off point for intervention analgesia in rabbits using the Bristol Rabbit Pain Scale. Veterinary Record 193(5), e2995.

Background: The objective of this study was to determine the threshold of the Bristol Rabbit Pain Scale (BRPS) indicating the need for intervention analgesia. Methods: Fourteen members of veterinary staff were recruited to rate rabbits...

Buhr, P., Kolstrup, S., Nikolajsen, L.-L. et al. 2023. The anaesthetic effects of ketamine/xylazine/midazolam in C57Bl/6JRj mice. Scandinavian Journal of Laboratory Animal Science 49, 21–27.

We wished to improve the efficacy and safety of ketamine/xylazine anaesthesia in C57Bl/6JRj mice and achieve a surgical anaesthesia lasting 20-30 minutes, aiming at fewer anaesthesia related deaths and using the subcutaneous injection route to...

Costa, R. S., Ciotti-McClallen, M., Tilley, R. et al. 2023. Intramuscular alfaxalone with or without buprenorphine or hydromorphone provides sedation with minimal adverse effects in healthy rabbits (Oryctolagus cuniculus) in a randomized blinded controlled trial. Journal of the American Veterinary Medical Association 261(2), 223–228.

OBJECTIVE To evaluate the effects of alfaxalone administered IM with or without buprenorphine or hydromorphone in healthy rabbits (Oryctolagus cuniculus). ANIMALS 24 male rabbits undergoing elective orchiectomy between August 21, 2021, and November 6, 2021...

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...

Cho, E., Walsh, C. A., D’Angelo-Gavrish, N. M. et al. 2023. Effects of housing density on reproductive performance, intracage ammonia, and welfare of mice continuously housed as breeders in standard mouse and rat caging. JAALAS 62(2), 116–122.

Maintaining compliance with cage density recommendations in The Guide for the Care and Use of Laboratory Animals precludes continuous trio breeding in standard-sized mouse cages. This study evaluated and compared several parameters of reproductive performance...

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...

Jimenez, I. A., Craney, M. C., Painter, M. C. et al. 2023. Behavioral evaluation of laboratory-housed ferrets (Mustela putorius furo) in different enclosure sizes. JAALAS 62(5), 382–394.

The domestic ferret (Mustela putorius furo) is a common research model for infectious disease and behavioral studies. Ferrets are social animals that are commonly pair-housed. The United States has no species-specific regulatory standards for housing...

Pinho, R. H., Justo, A. A., Cima, D. S. et al. 2023. Effects of human observer presence on pain assessment using facial expressions in rabbits. JAALAS 62(1), 81–86.

The goal of this study was to evaluate the effect of a human observer on Rabbit Grimace Scale (RbtGS) scores. The study scored video footage taken of 28 rabbits before and after orthopedic surgery, as...

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...

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...

Stover, M. G., Villano, J. S. 2022. Evaluation of various IVC systems according to mouse reproductive performance and husbandry and environmental parameters. JAALAS 61(1), 31-41.

IVC systems are marketed for improving the health and management of mouse colonies. The current study compared mouse reproductive performance and husbandry and environmental parameters among 3 high-density (HD) IVC rack systems (RS1, RS2, and...

Ziegler, A. A., Grobe, C. C., Reho, J. J. et al. 2022. Short-term housing in metabolic caging on measures of energy and fluid balance in male C57BL/6J mice (Mus musculus). JAALAS 61(2), 132-139.

Metabolic caging is an important tool for quantitative urine and feces collection in rodents, although significant limitations and problems accompany its use. Despite strong opinions among investigators regarding the effects of metabolic caging on energy...

Dancer, A. M. M., Díez-León, M., Bizley, J. K. et al. 2022. Housing and environmental enrichment of the domestic ferret: A multi-sector survey. Animals 12(9), 1065.

Ferrets (Mustela putorius furo) are kept and used in multiple sectors of society, but little is known about how they are housed and what environmental enrichment (EE) they may benefit from. We aimed to help...

Knaebe, B., Weiss, C. C., Zimmermann, J. et al. 2022. The promise of behavioral tracking systems for advancing primate animal welfare. Animals 12(13), 1648.

Recent years have witnessed major advances in the ability of computerized systems to track the positions of animals as they move through large and unconstrained environments. These systems have so far been a great boon...

Paterson, E. A., Turner, P. V. 2022. Challenges with assessing and treating pain in research primates: A focused survey and literature review. Animals 12(17), 2304.

Research primates may undergo surgical procedures making effective pain management essential to ensure good animal welfare and unbiased scientific data. Adequate pain mitigation is dependent on whether veterinarians, technicians, researchers, and caregivers can recognize and...

Davies, J. R., Purawijaya, D. A., Bartlett, J. M. et al. 2022. Impact of refinements to handling and restraint methods in mice. Animals 12(17), 2173.

There is increasing evidence that, compared to non-aversive handling methods (i.e., tunnel and cupping), tail handling has a negative impact on mouse welfare. Despite this evidence, there are still research organisations that continue to use...

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...

Barkus, C., Bergmann, C., Branco, T. et al. 2022. Refinements to rodent head fixation and fluid/food control for neuroscience. Journal of Neuroscience Methods 381, 109705.

The use of head fixation in mice is increasingly common in research, its use having initially been restricted to the field of sensory neuroscience. Head restraint has often been combined with fluid control, rather than...

Scariot, P. P., Gobatto, C. A., Polisel, E. E. et al. 2022. Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood. Laboratory Animals 56(4), 344-355.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging...

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...

MacLellan, A., Nazal, B., Young et al. 2022. Waking inactivity as a welfare indicator in laboratory mice: Investigating postures, facial expressions and depression-like states. Royal Society Open Science 9(11), 221083.

Animal welfare assessment relies on valid and practical indicators of affect. In mice, the most widely used research vertebrates, lying still with eyes open, inactive-but-awake (IBA) in the home cage, has potential to be one...

Ueno, H., Takahashi, Y., Murakami, S. et al. 2022. The prevention of home-cage grid climbing affects muscle strength in mice. Scientific Reports 12(1), 15263.

Experimenters and treatment methods are the major contributors to data variability in behavioral neuroscience. However, home cage characteristics are likely associated with data variability. Mice housed in breeding cages spontaneously exhibit behavioral patterns such as...

Fink, L. B., Mukobi, A., Gruber, L. et al. 2022. Longitudinal analysis of variability in fecal glucocorticoid metabolite concentrations in three orangutans (Pongo pygmaeus pygmaeus and Pongo pygmaeus abelii) before, during, and after transition from a regular habitat environment to temporary housing in indoor holding facilities. Animals 12(23), 3303.

Considerable research has been conducted on the effects of inter-institutional transfers, but far less consideration has been given to intra-institutional transfers and extended housing in off-habitat holding. On 15 May 2018, The Oregon Zoo’s orangutans...