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. 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...

Riddell, D. L., Hyndman, T. H., Bowden, R. S. et al. 2023. Use of a low-calorie flavored gel to facilitate oral self-administration of analgesics in mice. JAALAS 62(2), 163–169.

The goals of this study were to determine whether mice would adapt to a low-calorie flavored water gel as their sole source of hydration and whether the addition of acetaminophen, tramadol, meloxicam, or buprenorphine to...

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...

Yoshida, K. 2023. Comparison of low and high doses of pentobarbital or thiopental for euthanasia of isoflurane-anesthetized pigs. JAALAS 62(2), 185–188.

Barbiturate overdose is a common method for euthanizing pigs. However, barbiturates can cause tissue damage and may affect experimental results, so the minimal dose should be used. The minimal dose of barbiturate for euthanasia in...

Kieffer, J. D., Campler, M. R., Cheng, T.-Y. et al. 2022. Evaluation of a water-based medium-expansion foam depopulation method in suckling and finisher pigs. Animals 12(8), 1041.

The threat of foreign animal disease introduction through contaminated animal products, feed ingredients, and wildlife vectors have highlighted the need for additional approved methods for mass depopulation of swine under emergency scenarios, especially methods that...

Martins, T., Matos, A. F., Soares, J. et al. 2022. Comparison of gelatin flavors for oral dosing of C57BL/6J and FVB/N mice. JAALAS 61(1), 89-95.

Precise oral dosing in rodents is usually achieved by intragastric gavage. If performed incorrectly due to technical difficulties, inexperience, or animal resistance, oral gavage may have animal welfare implications such as esophageal and gastric rupture...

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...

Merlot, E., Meunier-Salaün, M.-C., Peuteman, B. et al. 2022. Improving maternal welfare during gestation has positive outcomes on neonatal survival and modulates offspring immune response in pigs. Physiology & Behavior 249, 113751.

Improving the housing of pregnant sows by giving them more space and access to deep straw had positive effects on their welfare, influenced their maternal behavior and improved the survival of their offspring. The present...

Bartlett, J., Davies, J., Purawijaya, D. et al. 2022. Refinement of handling and dosing methods for rats and mice. Animal Technology and Welfare 21(2), 120-124.

Modified Handling for Mice: Handling mice by gripping the base of the tail has been shown to negatively impact animal welfare by increasing anxiety and aversion to handling. We aimed to refi ne the dosing...

Donaldson-Wing, M. 2022. Medicated jelly as a replacement for injectables and the use of Maropitant to manage itchy skin in mice. Animal Technology and Welfare 21(2), 134-136.

It is desirable to administer drugs by the least invasive route to (1) optimise welfare, (2) reduce the risk of injury to animal handlers and (3) minimise the impact of restraint and transient pain on...

Kinane, O., Butler, F., O’Driscoll, K. 2022. Freedom to move: Free lactation pens improve sow welfare. Animals 12(14), 1762.

Farrowing crates present a major animal welfare problem. This study investigated the effects of temporary confinement at farrowing on sow welfare and aimed to determine whether this type of system could improve sow welfare through...

Conrad, L., Aubé, L., Heuchan, E. et al. 2022. Effects of farrowing hut design on maternal and thermoregulatory behaviour in outdoor housed sows and piglets. Applied Animal Behaviour Science 251, 105616.

This study aimed to determine the effect of three different farrowing huts on the behaviour of outdoor housed sows and piglets during summer in Eastern Canada, with a focus on thermoregulatory and crushing behaviours. Forty-two...

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...

Chesler, K. C., Motz, C. T., Bales, K. L. et al. 2022. Voluntary oral dosing for precise experimental compound delivery in adult rats. Laboratory Animals 56(2), 147-156.

Preclinical drug studies routinely administer experimental compounds to animal models with the goal of minimizing potential adverse events from the procedure. In this study, we assessed the ability to train adult male Long Evans rats...

Neto, T., Faustino-Rocha, A. I., Gil da Costa, R. M. et al. 2022. A quick and low-intensity method for oral administration to large numbers of mice: A possible alternative to oral gavage. Laboratory Animals 56(2), 185-190.

Oral administration of medication to experimental animals is a cause of significant stress. When coupled to animals who are already under strenuous circumstances due to the disease being modelled, there is a significant risk for...

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...

Korenyi-Both, J., Vidaurre, J., Held, T. et al. 2022. Description of electroencephalographic data gathered using water-based medium-expansion foam as a depopulation method for nursery pigs. Scientific Reports 12(1), 16798.

The United States’ swine industry is under constant threat of foreign animal diseases, which may emerge without warning due to the globalized transportation networks moving people, animals, and products. Therefore, having disease control and elimination...

Parois, S. P., Van Der Zande, L. E., Knol, E. F. et al. 2022. A multi-suckling system combined with an enriched housing environment during the growing period promotes resilience to various challenges in pigs. Scientific Reports 12(1), 6804.

Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience...

Baxter, E. M., Moustsen, V. A., Goumon, S. et al. 2022. Transitioning from crates to free farrowing: A roadmap to navigate key decisions. Frontiers in Veterinary Science 9, 998192.

There are animal welfare concerns about the continued use of permanent crating systems for farrowing and lactating sows, which is the most prevalent maternity system in global pig production. Greater societal attention in recent years...

Chou, J.-Y., Parsons, T. D. 2022. A systematic review of the impact of housing on sow welfare during post-weaning and early pregnancy periods. Frontiers in Veterinary Science 9, 903822.

Breeder animals are an important focus in farm animal welfare assessments as they typically live the longest lives and are at the greatest risk for suffering due to their longevity. For breeding pigs, the time...

Korenyi-Both, J., Vidaurre, J., Held, T. et al. 2022. Description of electroencephalographic data gathered using water-based medium-expansion foam as a depopulation method for nursery pigs. Scientific Reports 12(1), 16798.

The United States’ swine industry is under constant threat of foreign animal diseases, which may emerge without warning due to the globalized transportation networks moving people, animals, and products. Therefore, having disease control and elimination...

Martin, J. E., Baxter, E. M., Clarkson, J. M. et al. 2022. Characterizing candidate decompression rates for hypobaric hypoxic stunning of pigs. Part 1: Reflexive behavior and physiological responses. Frontiers in Veterinary Science 9, 1027878.

Alternatives to carbon dioxide (CO2) stunning for the commercial slaughter of pigs are urgently needed because there is robust evidence that exposing pigs to hypercapnic environments is associated with pain, fear, and distress. Hypobaric hypoxia...

Parois, S. P., Van Der Zande, L. E., Knol, E. F. et al. 2022. A multi-suckling system combined with an enriched housing environment during the growing period promotes resilience to various challenges in pigs. Scientific Reports 12(1), 6804.

Little is known about the impact of social and environmental enrichment on improving livestock resilience, i.e. the ability to quickly recover from perturbations. We evaluated the effect of an alternative housing system (AHS) on resilience...