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. 
Jardat, P., Calandreau, L., Ferreira, V. et al. 2022. Pet-directed speech improves horses' attention toward humans. Scientific Reports 12(1), 4297.

In a recent experiment, we showed that horses are sensitive to pet-directed speech (PDS), a kind of speech used to talk to companion animals that is characterized by high pitch and wide pitch variations. When...

Popper, A. N., Sisneros, J. A. 2022. The sound world of zebrafish: A critical review of hearing assessment. Zebrafish 19(2), 37-48.

Zebrafish, like all fish species, use sound to learn about their environment. Thus, human-generated (anthropogenic) sound added to the environment has the potential to disrupt the detection of biologically relevant sounds, alter behavior, impact fitness...

Eisenbeiser, S., Serbe-Kamp, É., Gage, G. J. et al. 2022. Gills just want to have fun: Can fish play games, just like us? Animals 12(13), 1684.

It is common to observe play in dogs, cats, and birds, but have we been ignoring play in one of the most common house pets of all… fish? Aquarium fish are often used as meditative...

Davis, A. K., Garner, J. P., Chu, D. K. et al. 2022. Propofol immersion as a euthanasia method for adult zebrafish (Danio rerio). Comparative Medicine 72(3), 204-209.

The exponential rise of the zebrafish (Danio rerio) as a model organism in biomedical research has far outstripped our un- derstanding of basic husbandry and welfare for this species. As a case in point, here...

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...

Zausinger, P., Schneider, B. M., Bauer, A. et al. 2022. Short communication: Do the tameness of the dams and the sex of the offspring have an influence on the “gentling” effect in laboratory rats? Journal of Veterinary Behavior 52-53, 45-49.

“Gentling” (soft touching, “taming”) has long-term effects on the behavior of laboratory rats (Rattus norvegicus). Our own studies showed that the use of a “gentling” program in the fourth and fifth week of life resulted...

Riedesel, A.-K., Bach-Hagemann, A., Abdulbaki, A. et al. 2022. Burrowing behaviour of rats: Strain differences and applicability as well-being parameter after intracranial surgery. Laboratory Animals 56(4), 356-369.

In mice, burrowing is considered a species-typical parameter for assessing well-being, while this is less clear in rats. This exploratory study evaluated burrowing behaviour in three rat strains during training and in the direct postoperative...

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...

Hwang, S.-K., Tyszkiewicz, C., Dragon, M. et al. 2022. Introduction of gloved hand to cage induces 22-kHz ultrasonic vocalizations in male albino rats. PLOS ONE 17(11), e0278034.

Rodents emit ultrasonic vocalizations (USVs) above the human hearing threshold of ~ 20 kHz to communicate emotional states and to coordinate their social interactive behavior. Twenty-two kHz USVs emitted by adult rats have been reported...

Ferreira, J. M., Félix, L., Jorge, S. et al. 2022. Anesthesia overdose versus rapid cooling for euthanasia of adult zebrafish. Zebrafish 19(4), 148-159.

The rapid increase in zebrafish use needs to be accompanied by research into the refinement of procedures. The European (EU) Directive lists three possible euthanasia methods for fish: anesthetic overdose, electrical stunning, and concussion. However...

Greening, L., McBride, S. 2022. A review of equine sleep: Implications for equine welfare. Frontiers in Veterinary Science 9, 916737.

Sleep is a significant biological requirement for all living mammals due to its restorative properties and its cognitive role in memory consolidation. Sleep is ubiquitous amongst all mammals but sleep profiles differ between species dependent...

Pellis, S. M., Pellis, V. C., Ham, J. R. et al. 2022. The rough-and-tumble play of rats as a natural behavior suitable for studying the social brain. Frontiers in Behavioral Neuroscience 16, 1033999.

Laboratory rats have been an important model species with which to study the neurobiology of rough-and-tumble play (RTP). RTP in rats involves competition to gain access to the partner’s nape of the neck, which is...

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...

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...

Coleman, K., Shapiro, S. J. (Eds.). 2021. Behavioral Biology of Laboratory Animals (1st ed). CRC Press, Boca Raton, FL.

This 30-chapter volume informs students and professionals about the behavioral biology of animals commonly housed in laboratory and other captive settings. Each species evolved under specific environmental conditions, resulting in unique behavioral patterns, many of...

Sørensen, D., Cloutier, S., Gaskill, B. (Eds.). 2021. Animal-centric Care and Management - Enhancing Refinement in Biomedical Research. CRC Press, Boca Raton, FL.

The concept of the 3Rs (Refinement, Reduction and Replacement) has been used as a framework for improving the welfare of laboratory animals for the last half century. By establishing an animal-centric view on housing and...

Silva-Reis, R., Faustino-Rocha, A. I., Gonçalves, M. et al. 2021. Refinement of animal model of colorectal carcinogenesis through the definition of novel humane endpoints. Animals 11(4), 985.

This study aimed to define appropriate humane endpoints (HEs) for an animal model of colorectal carcinogenesis (CRC). Twenty-nine male Wistar rats were divided into two control groups (CTRL1 and CTRL2) injected with ethylenediamine tetraacetic acid...

Merkies, K., Franzin, O. 2021. Enhanced understanding of horse–human interactions to optimize welfare. Animals 11(5), 1347.

Horses (Equus caballus) have been domesticated for millennia and are regularly utilized for work, sport, and companionship. Enhanced understanding of human–horse interactions can create avenues to optimize their welfare. This review explores the current research...

Krueger, K., Esch, L., Farmer, K. et al. 2021. Basic needs in horses?—A literature review. Animals 11(6), 1798.

Every animal species has particular environmental requirements that are essential for its welfare, and when these so-called “basic needs” are not fulfilled, the animals suffer. The basic needs of horses have been claimed to be...

Bombail, V., Brown, S. M., Hammond, T. J. et al. 2021. Crying with laughter: Adapting the tickling protocol to address individual differences among rats in their response to playful handling. Frontiers in Veterinary Science 8, 677872.

In this Opinion paper, we consider whether current methods of tickling overemphasize the use of pinning (Figure 1) to which there may be a wider response variation than commonly acknowledged. We do not dispute that...

Ellis, T., Katsiadaki, I. 2021. Clarification of early end-points for refinement of animal experiments, with specific reference to fish. Laboratory Animals 55(3), 244-253.

Appropriate end-points are integral to the refinement of laboratory animal experiments. Our recent experience has highlighted that ambiguity around end-points is hampering their adoption in experiments that cause severe suffering to fish. In toxicology, the...

Kay, W. R., Mawson, P. R. 2021. An efficient method for the euthanasia of cane toads (Rhinella marina) under northern Australian field conditions. Animals 11(8), 2239.

The euthanasia of cane toads under field conditions presents a number of logistical and animal welfare challenges. One recommended method of control involves the use of carbon dioxide in plastic bags. This paper describes the...

Kelly, K. J., McDuffee, L. A., Mears, K. 2021. The effect of human–horse interactions on equine behaviour, physiology, and welfare: A scoping review. Animals 11(10), 2782.

Human–horse interactions (HHIs) are diverse and prominent in the equine industry. Stakeholders have an invested interest in making sure that HHIs are humane. Assessment of equine welfare goes beyond physical health and includes assessment of...

De Santis, M., Seganfreddo, S., Galardi, M. et al. 2021. Donkey behaviour and cognition: A literature review. Applied Animal Behaviour Science 244, 105485.

Despite their diffusion worldwide, many aspects of donkeys’ behaviour and cognitive abilities are still poorly understood and overshadowed by a corpus of commonplaces. The possibility of better knowing this species is of key relevance for...

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...