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. 
Golledge, H., Richardson, C. (Eds.) 2024. The UFAW Handbook on the Care and Management of Laboratory and Other Research Animals (9th ed.). Wiley-Blackwell. 1040 p.

The latest edition of the seminal reference on the care and management of laboratory and research animals. The newly revised ninth edition of The UFAW Handbook on the Care and Management of Laboratory and Other...

Robinson, L. M., Weiss, A. (Eds.) 2023. Nonhuman Primate Welfare: From History, Science, and Ethics to Practice. Springer, Cham, Switzerland. 671 p.

This volume reviews the broad topic of welfare in nonhuman primates under human care. Chapters detail the history of primates in captivity, ethical and legal issues surrounding the use of nonhuman primates as entertainment or...

Attokaren, M. K., Jeong, N., Blanpain, L. et al. 2023. BrainWAVE: A flexible method for noninvasive stimulation of brain rhythms across species. ENeuro 10(2) ENEURO.0257-22.2022.

Rhythmic neural activity, which coordinates brain regions and neurons to achieve multiple brain functions, is impaired in many diseases. Despite the therapeutic potential of driving brain rhythms, methods to noninvasively target deep brain regions are...

Domínguez-Oliva, A., Hernández-Ávalos, I., Olmos-Hernández, A. et al. 2023. Thermal response of laboratory rats (Rattus norvegicus) during the application of six methods of euthanasia assessed by infrared thermography. Animals 13(18), 2820.

Refinement is one of the principles aiming to promote welfare in research animals. The techniques used during an experimental protocol, including euthanasia selection, must prevent and minimize suffering. Although the current euthanasia methods applied to...

Domínguez-Oliva, A., Olmos-Hernández, A., Hernández-Ávalos, I. et al. 2023. Rat grimace scale as a method to evaluate animal welfare, nociception, and quality of the euthanasia method of wistar rats. Animals 13(20), 3161.

Refinement of experimental procedures in animal research has the objective of preventing and minimizing pain/distress in animals, including the euthanasia period. This study aimed to evaluate pain associated with six methods of euthanasia in Wistar...

Stevens, C., Hammonds, T., Hinchcliffe, J. et al. 2023. Report of the 2022 RSPCA/UFAW Rodent Welfare Group Meeting. Animal Technology and Welfare 22(2), 91–100.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 29 years, so that its members can discuss current welfare research, exchange views on welfare issues and share experiences of...

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...

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...

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...

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...

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...

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...

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...

Hepps Keeney, C., Harrison, T. M. 2022. Euthanasia complications in non-domestic species. Journal of Zoological and Botanical Gardens 3(4), 616–623.

There are very few studies describing euthanasia complications in non-domestic species. The goal of this study was to survey veterinarians to determine what complications may commonly occur during the euthanasia of non-domestic species. An online...

Zeng, Y., Jin, H., Wang, J. et al. 2022. An optimized method for intratracheal instillation in mice. Journal of Pharmacological and Toxicological Methods 118, 107230.

Non-invasive intratracheal instillation is an important method for direct exposure of the respiratory tract which is commonly used in toxicology, environmental science, and other research fields. However, there is no standard operating process for non-invasive...

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...

Améndola, L., Ratuski, A., Weary, D. M. 2021. Individual differences in rat sensitivity to CO2. PLOS ONE 16(1), e0245347.

Feelings of fear, anxiety, dyspnea and panic when inhaling carbon dioxide (CO2) are variable among humans, in part due to differences in CO2 sensitivity. Rat aversion to CO2 consistently varies between individuals; this variation in...

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...

Le Balle, R., Cote, J., Santos Fernandez, F. A. 2021. Evidence for animal personalities in two Brazilian tortoises (Chelonoidis denticulatus and Chelonoidis carbonarius) and insights for their conservation. Applied Animal Behaviour Science 241, 105400.

Animal personality, the consistent between-individual differences in e.g., risk-taking, exploration, antipredator or mating behaviours, has major impacts on the fitness of individuals in many species. Understanding how to quantify animal personality should help us predicting...

de A. P. Ramos, G., de Azevedo, C. S., Jardim, T. H. A. et al. 2021. Temperament in captivity, environmental enrichment, flight ability, and response to humans in an endangered parrot species. Journal of Applied Animal Welfare Science 24(4), 379-391.

Temperament assessment is useful in reintroduction programs. Reactivity to humans and flight ability are also important behavioral aspects for captive parrots candidates to reintroduction. The study aimed: a) to evaluate if behavioral responses to environmental...

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...