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. 
Krueger, L. D., Thurston, S. E., Kirk, J. et al. 2020. Enrichment preferences of singly housed zebrafish (Danio rerio). JAALAS 59(2), 148–155.

Despite the increasing popularity of zebrafish (Danio rerio) as an animal model, the environmental enrichment preferences of this species have been largely unexplored. We sought to determine the preferences of mature female zebrafish that were...

Shomer, N. H., Allen-Worthington, K. H., Hickman, D. L. et al. 2020. Review of rodent euthanasia methods. JAALAS 59(3), 242–253.

The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the...

Galex, I. A., Gallant, C. M., D'Avignon, N. et al. 2020. Evaluation of effective and practical euthanasia methods for larval African clawed frogs (Xenopus laevis). JAALAS 59(3), 269–274.

Larval, or tadpole-stage Xenopus laevis frogs are a popular research model for developmental biology and disease studies. Existing euthanasia guidance documents offer recommendations for both eggs and adult stages, yet do not specifically address the...

Greene, L. K., Clarke, T. A., Southworth, C. A. et al. 2020. Daily lettuce supplements promote foraging behavior and modify the gut microbiota in captive frugivores. Zoo Biology 39(5), 334-344.

For captive primates, greater provisioning of leafy greens or foliage can promote natural foraging behavior while boosting fiber intake. Recalcitrant fiber, although minimally available to endogenous metabolism, is readily fermented into nutrients by gut microbes...

Tilley, C. A., Carreño Gutierrez, H., Sebire, M. et al. 2020. Skin swabbing is a refined technique to collect DNA from model fish species. Scientific Reports 10(1), 18212.

Model fish species such as sticklebacks and zebrafish are frequently used in studies that require DNA to be collected from live animals. This is typically achieved by fin clipping, a procedure that is simple and...

Mellor, E. L., Cuthill, I. C., Schwitzer, C. et al. 2020. Large lemurs: Ecological, demographic and environmental risk factors for weight gain in captivity. Animals 10(8), 1443.

Excessive body mass, i.e., being overweight or obese, is a health concern associated with issues such as reduced fertility and lifespan. Some lemur species are prone to extreme weight gain in captivity, yet others are...

Tan, S. L. T., Handasyde, K. A., Rault, J.-L. et al. 2020. Insensitivity to reward shifts in zebrafish (Danio rerio) and implications for assessing affective states. Animal Cognition 23(1), 87–100

Theory and empirical findings predict that individuals in a negative affective state are more sensitive to unexpected reward loss and less sensitive to unexpected reward gain compared to individuals in a neutral or positive affective...

Arechavala-Lopez, P., Saraiva, J. L. 2019. Welfare of Cultured and Experimental Fishes. Basel, Switzerland: MDPI, 132 pages.

This open access book is a printed edition of the Special Issue on Welfare of Cultured and Experimental Fishes that was published in the journal Fishes. The PDF is free for download.

Woodward, M. A., Winder, L. A., Watt, P. J. 2019. Enrichment increases aggression in zebrafish. Fishes 4(1), 22.

Environmental enrichment, or the enhancement of an animal’s surroundings when in captivity to maximise its wellbeing, has been increasingly applied to fish species, particularly those used commercially. Laboratory species could also benefit from enrichment, but...

Axiak Flammer, S., Eskes, C., Kohler, I. et al. 2019. Alternatives to carbon dioxide—Taking responsibility for humanely ending the life of animals. Animals 9(8), 482.

Carbon dioxide (CO2) is commonly used to kill rodents. However, a large body of research has now established that CO2 is aversive to them. A multidisciplinary symposium organized by the Swiss Federal Food Safety and...

DePasquale, C., Fettrow, S., Sturgill, J. et al. 2019. The impact of flow and physical enrichment on preferences in zebrafish. Applied Animal Behaviour Science 215, 77-81.

Environmental enrichment is used extensively to improve the welfare of animals in captivity, however, the importance of physical exercise as enrichment is only now coming to light. A key question in assessing the welfare of...

Lee, C. J., Paull, G. C., Tyler, C. R. 2019. Effects of environmental enrichment on survivorship, growth, sex ratio and behaviour in laboratory maintained zebrafish Danio rerio. Journal of Fish Biology 94(1), 86-95.

Environmental enrichment involves increasing the complexity of a fish's environment in order to improve welfare. Researchers are legally obliged to consider the welfare of laboratory animals and poor welfare may result in less robust data...

Jones, N. A. R., Spence, R., Jones, F. A. M. et al. 2019. Shade as enrichment: Testing preferences for shelter in two model fish species. Journal of Fish Biology 95(4), 1161-1165.

We compared preferences shown by zebrafish (Danio rerio) and three-spined stickleback (Gasterosteus aculeatus) for shelter provided by above-tank shade and artificial plants. Zebrafish showed no preference for either shelter, whereas sticklebacks showed a preference for...

Animal Welfare Institute. 2019. Let’s get serious about animal play. AWI Quarterly 68(3) Fall, 19.

This article describes the importance of providing laboratory animals with opportunities to engage in play, and provides a few practical ideas for how to do this.

Heyworth, C., Owens, D. 2019. Eureka! Enhanced water recipe and enrichment for oocyte quality and embryo development in the African clawed frog (Xenopus laevis). Laboratory Animal Science Professional 7(1) (March), 43-45.

Husbandry staff set a goal to develop a health monitoring program for a Xenopus laevis colony that included not only specific pathogen freedom, but wellness. This article describes environmental enrichment and a water recipe for...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...

Dunford, K., Hakkesteeg, J., Wilson, C. 2019. Stiff as a board: Measuring rigor mortis in zebrafish. Animal Technology and Welfare 18(3), 203-205.

Schedule one killing (S1K) methods require a two-step process: a humane method of death, typically for Zebrafish an anaesthetic overdose and confirmation of death, such as confirmation of rigor mortis. There is widespread variation of...

Thurman, C. E., Rasmussen, S., Prestia, K. A. 2019. Effect of 3 euthanasia methods on serum yield and serum cortisol concentration in zebrafish (Danio rerio). JAALAS 58(6), 823–828.

Zebrafish are an important model in neuroscience and developmental biology and are also an emerging model in hematology and immunology. Little information is available for zebrafish regarding the physiologic impact of different euthanasia methods and...

Špinka, M. 2019. Animal agency, animal awareness and animal welfare. Animal Welfare 28(1), 11–20.

In nature, animals need to actively engage with the environment in order to prosper in survival and reproduction. Hence, agency is a central adaptive characteristic of animal life. In this paper, I propose that from...

Lambert, C. J., Freshner, B. C., Chung, A. et al. 2018. An automated system for rapid cellular extraction from live zebrafish embryos and larvae: Development and application to genotyping. PLOS ONE 13(3), e0193180.

Zebrafish are a valuable model organism in biomedical research. Their rapid development, ability to model human diseases, utility for testing genetic variants identified from next-generation sequencing, amenity to CRISPR mutagenesis, and potential for therapeutic compound...

Cooke, G. M. 2018. Use of a translucent refuge for Xenopus tropicalis with the aim of improving welfare. Laboratory Animals 52(3), 304-307.

Xenopus tropicalis is an increasingly important animal model in a variety of biological research fields. In many countries legislation exists to promote and increase welfare wherever possible, including the ability to view animals during daily...

Costa, R., Sousa, C., Llorente, M. 2018. Assessment of environmental enrichment for different primate species under low budget: A case study. Journal of Applied Animal Welfare Science 21(2), 185-199.

The 2011 European Union Zoo Inquiry presented evidence that most zoos fail to achieve adequate levels of nonhuman animal welfare. Appropriate environmental enrichment (EE) can play a role in the promotion of welfare. However, financial...

Grist, A., Lines, J., Knowles, T. et al. 2018. Use of a non-penetrating captive bolt for euthanasia of neonate goats. Animals 8(4), 58.

A non-penetrating captive bolt device, powered by a 1 grain 0.22″ cartridge delivering a calculated kinetic energy of 47 Joules was tested as a euthanasia method on 200 neonate goats (Capra aegagrus hircus) of mean...

Wallace, C. K., Bright, L. A., Marx, J. O. et al. 2018. Effectiveness of rapid cooling as a method of euthanasia for young zebrafish (Danio rerio). JAALAS 57(1), 58-63.

Despite increased use of zebrafish (Danio rerio) in biomedical research, consistent information regarding appropriate euthanasia methods, particularly for embryos, is sparse. Current literature indicates that rapid cooling is an effective method of euthanasia for adult...

Shapiro, M. E., Shapiro, H. G., Ehmke, E. E. 2018. Behavioral responses of three lemur species to different food enrichment devices. Zoo Biology 37(3), 146–155.

Environmental enrichment is a tool used to promote the welfare and well‐being of captive animals by encouraging the display of species‐specific behaviors and reducing the stress or boredom induced by captive environments. Lemurs are highly...