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. 
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...

McKenzie, D. J., Sadoul, B., Geffroy, B. 2019. Measuring cortisol, the major stress hormone in fishes. Journal of Fish Biology 94(4), 540-555.

Stress in teleosts is an increasingly studied topic because of its interaction with growth, reproduction, immune system and ultimately fitness of the animal. Whether it is for evaluating welfare in aquaculture, adaptive capacities in fish...

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.

Animal Welfare Institute. 2019. Rabbit enrichment items: Getting bang for the buck (and doe). AWI Quarterly 68(1) Spring, 24-25.

A recent discussion on the Laboratory Animal Refinement and Enrichment Forum (LAREF) focused on new enrichment ideas for rabbits. Contributors shared their experiences about which toys and treats get rave reviews from rabbits.

Heyworth, C. 2019. Inventive enrichment to facilitate weight gain in the common marmoset (Callithrix jacchus) during invasive studies. Laboratory Animal Science Professional 7(4) (December), 38-41.

To provide the highest standard of care to marmosets during invasive surgical studies, studies that often lead to weight loss, it is paramount to call upon inherent species-specific enrichment tactics to mitigate weight loss. Weight...

Bennett, A., Newell, M. 2019. The cat conundrum: Improving welfare and reducing stress for cats and their handlers through primary enclosure refinement. Laboratory Animal Science Professional 7(1) (March), 49-51.

In the lab, social housing of cats is a challenge due to the proximity of conspecifics made necessary by the relatively small size of typical standard caging. Handling is a challenge, as human injury due...

Edwards, K. L., Miller, M. A., Carlstead, K. et al. 2019. Relationships between housing and management factors and clinical health events in elephants in North American zoos. PLOS ONE 14(6), e0217774.

Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or...

Brown, J. L., Carlstead, K., Bray, J. D. et al. 2019. Individual and environmental risk factors associated with fecal glucocorticoid metabolite concentrations in zoo-housed Asian and African elephants. PLOS ONE 14(9), e0217326.

A recent large-scale welfare study in North America involving 106 Asian (Elephas maximus) and 131 African (Loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number...

van der Leij, W. J. R., Selman, L. D. A. M., Vernooij, J. C. M. et al. 2019. The effect of a hiding box on stress levels and body weight in Dutch shelter cats; a randomized controlled trial. PLOS ONE 14(10), e0223492.

While staying in an animal shelter, cats may suffer from chronic stress which impairs their health and welfare. Providing opportunities to hide can significantly reduce behavioural stress in cats, but confirmation with physical parameters is...

Ishizuka, S., Kawamoto, Y., Toda, K. et al. 2019. Bonobos’ saliva remaining on the pith of terrestrial herbaceous vegetation can serve as non-invasive wild genetic resources. Primates 60(1), 7–13.

Evaluating the genetic diversity of natural populations of endangered species is important for conservation. Although the genetic analysis of wildlife usually requires collecting DNA non-invasively, the variety of non-invasive DNA sampling methods is limited for...

Anderson, J. R., Ang, M. Y. L., Lock, L. C. et al. 2019. Nesting, sleeping, and nighttime behaviors in wild and captive great apes. Primates 60(4), 321–332.

The past few decades have seen a burgeoning of scientific studies on great apes’ use of nests for sleeping in the wild, as well as their nesting behavior and sleep in captivity. We review recent...

Broche Jr., N., Takeshita, R. S. C., Mouri, K. et al. 2019. Salivary alpha-amylase enzyme is a non-invasive biomarker of acute stress in Japanese macaques (Macaca fuscata). Primates volume 60(6), 547–558.

Salivary alpha-amylase (sAA) enzyme functions as a digestive enzyme in many species that consume starch in their diet. Human studies have also revealed that sAA enzyme activity levels are positively correlated with the release of...

Egelkamp, C. L., Ross, S. R. 2019. A review of zoo-based cognitive research using touchscreen interfaces. Zoo Biology 38(2), 220-235.

In the past few decades, there has been an increase in the number of zoo-based touchscreen studies of animal cognition around the world. Such studies have contributed to the field of comparative cognition despite the...

Leeds, A., Lukas, K. E. 2019. Monitoring the social behavior of a bachelor mandrill (Mandrillus sphinx) dyad participating in touchscreen-mediated cognitive testing. Zoo Biology 38(4), 397-402.

Cognitive testing of primates in zoos is becoming increasingly common. Cognition experiments are generally thought to be beneficial as they provide participants with an opportunity to engage in species-specific cognitive functioning, perhaps more so than...

Scott, N. L., LaDue, C. A. 2019. The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces. Zoo Biology 38(5), 448-457.

Population-level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure...

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...

Arnaud-James, L. 2019. The effects of structural and feeding enrichments on captive western hoolock gibbons at the rehabilitation and release centre HURO Programme, India. Canopy 20(1), 15-18.

The aim of this study was to assess the impacts of different enrichments in various enclosures in a gibbon rehabilitation centre in the northeast of India. The results show a greater interaction with the feeding...

White, K. 2019. Effects of captivity on the activity budgets of lar gibbons (Hylobates lar). Canopy 20(1), 43-45.

The keeping of gibbons in a captive environment and recreating an appropriate habitat is essential to enable them to exhibit species-specific behaviour. This research was designed to provide baseline data on the activity budgets of...

Wooddell, L. J., Beisner, B., Hannibal, Darcy L. et al. 2019. Increased produce enrichment reduces trauma in socially-housed captive rhesus macaques (Macaca mulatta). American Journal of Primatology 81(12), e23073.

Due to primate adaptations for sociality, captive rhesus macaques have optimal welfare and utility as a biomedical model when they can be maintained in outdoor social groups. As a despotic species; however, aggression can result...

Schmitt, V. 2019. Implementing portable touchscreen-setups to enhance cognitive research and enrich zoo-housed animals. Journal of Zoo and Aquarium Research 7(2), 50-58.

To understand the evolutionary development of cognition, comparing the cognitive capacities of different animal species is essential. However, getting access to various species with sufficient sample sizes can be very challenging. Zoos, housing large ranges...

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...

Hacker, C. E., Miller, L. J., Schulte, B. A. 2018. Examination of enrichment using space and food for African elephants (Loxodonta africana) at the San Diego Zoo Safari Park. Animal Welfare 27(1), 55-65.

Concern for elephant welfare in zoological facilities has prompted a number of exhibit and management modifications, including those involving enrichment. Knowledge of how these changes impact indicators of welfare, such as elephant movement and behaviour...

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...

Lutz, C. K., Brown, T. A. 2018. Porches as enrichment for singly housed cynomolgus macaques (Macaca fascicularis). JAALAS 57(2), 138-142.

Effective environmental enrichment is used by animals, promotes species-typical behavior, and decreases abnormal behavior. Porches attached to the front of an animal's cage provide additional space, perching opportunities, and a better view of the surroundings...