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. 
Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be...

Bozzay, J. D., Walker, P. F., Atwood, R. E. et al. 2023. Development, refinement, and characterization of a nonhuman primate critical care environment. PLOS ONE 18(3), e0281548.

Systemic inflammatory response remains a poorly understood cause of morbidity and mortality after traumatic injury. Recent nonhuman primate (NHP) trauma models have been used to characterize the systemic response to trauma, but none have incorporated...

Gauy, A. C. dos S., Bolognesi, M. C., Gonçalves-de-Freitas, E. 2023. Body tactile stimulation reduces the effects of high stocking density on the welfare of Nile tilapia (Oreochromis niloticus). Fishes 8(6), 320.

High stocking density is used in aquaculture to optimize farming. However, such strategies can stress territorial fish by increasing aggression, thus harming the fish welfare and productive performance. Here, we tested the effect of long-term...

Bradley, H. S., Craig, M. D., Tomlinson, S. et al. 2023. Ecological considerations when designing mitigation translocations: An Australian reptile case study. Animals 13(16), 2594.

Translocation science has made considerable progress over the last two decades; however, reptile translocations still frequently fail around the world. Major knowledge gaps surround the basic ecology of reptile species, including basic factors such as...

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...

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...

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...

Hirata, S. 2022. Sky after 30 years: A brief biography of three biomedical research chimpanzees in Japan. Primates 63(2), 105–108.

This article describes the strategies employed by Kumamoto Sanctuary in Japan to integrate 3 retired chimpanzees – who each spent 30 years singly housed in a biomedical facility – with the sanctuary’s other residents.

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...

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...

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...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

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...

Ramos, J., Balasch, J. C., Tort, L. 2021. About welfare and stress in the early stages of fish. Frontiers in Veterinary Science 8, 634434.

In conclusion, the investigations carried out up to now demonstrate that during the early stages fish show high sensitivity to many types of stressors involving an array of responses to overcome alterations that could affect...

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...

Argüelles, J., Echaniz, M., Bowen, J. et al. 2021. The impact of a stress-reducing protocol on the quality of pre-anaesthesia in cats. Veterinary Record 188(12), e138.

Introduction: Transport to the clinic is a major source of stress for cats. The process involves being put into a carrier, driven in a car and handled. Cats are therefore removed from the safe-haven of...

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...

Locklear, J., Whiteside, T. E. 2021. Optimal colloidal water gel type and novel placement for frequent travelers. Laboratory Animal Science Professional 9(6) (November/December), 38-40.

During transportation, animals must have a water source available to prevent dehydration. Some shipping facilities use potatoes whereas, others use colloidal water gels that provide a uniform water source. The problem occurs when colloidal water...

Składanowska-Baryza, J., Ludwiczak, A., Pruszyńska-Oszmałek, E. et al. 2020. Effect of two different stunning methods on the quality traits of rabbit meat. Animals 10(4), 700.

The aim of the study was to assess the effect of two different stunning methods on the level of blood stress indicators (cortisol, insulin, glucose) and rabbit meat quality. The experiment was conducted on crossbreds...

Frost, K., Shah, M., Leung , V. S. Y. et al. 2020. Aversion to desflurane and isoflurane in Sprague-Dawley rats (Rattus norvegicus). Animals 10(6), 950.

Carbon dioxide and isoflurane are widely used for killing rats, yet may not truly achieve “euthanasia”, because they elicit aversion. The inhalant anesthetic desflurane is faster acting than isoflurane, representing a potential refinement. Using an...

Ballantine, A., Rodgers, D., Watts, C. et al. 2020. The cotton rat – a new challenge. Animal Technology and Welfare 19(1), 92-95.

This poster describes how the Animal Technologists at Envigo adapted their current practices and procedures for a new species at their laboratory: the cotton rat. The paper describes cotton rat biology and behaviour; housing; environmental...

Améndola, L., Weary, D. M. 2020. Understanding rat emotional responses to CO2. Translational Psychiatry 10, 253.

The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO2) exposure. The studies reviewed show that CO2 exposure is aversive to rats, and that rats respond to CO2...

Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss...