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. 
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...

Schiffmann, C., Clauss, M. 2019. Impact of a new exhibit on stereotypic behavior in an elderly captive African elephant. Journal of Zoo and Aquarium Research 7(1), 37-43.

Stereotypic behavior in zoo elephants is considered an indicator of impaired welfare. The underlying causes are diverse and many aspects are still unexplored. Nevertheless, many zoological institutions take huge efforts to improve the well-being of...

Fischer, C. P., Romero, L. M. 2019. Chronic captivity stress in wild animals is highly species-specific. Conservation Physiology 7(1), coz093.

Wild animals are brought into captivity for many reasons—conservation, research, agriculture and the exotic pet trade. While the physical needs of animals are met in captivity, the conditions of confinement and exposure to humans can...

Williams, E., Chadwick, C. L., Yon, L. et al. 2018. A review of current indicators of welfare in captive elephants (Loxodonta africana and Elephas maximus). Animal Welfare 27(3), 235-249.

Concerns over elephant welfare in UK zoos have implications for their future in captivity. To monitor improvements made to elephant welfare in UK zoos, non-invasive, valid and reliable indicators of welfare are needed. Using a...

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...

Bacon, H. 2018. Behaviour-based husbandry—A holistic approach to the management of abnormal repetitive behaviors. Animals 8(7), 103.

The field of zoo animal welfare science has developed significantly over recent years. However despite this progress in terms of scientific research, globally, zoo animals still face many welfare challenges. Recently, animal welfare frameworks such...

Clegg, I. 2018. Cognitive bias in zoo animals: An optimistic outlook for welfare assessment. Animals 8(7), 104.

Cognitive bias testing measures how emotional states can affect cognitive processes, often described using the “glass half-full/half-empty” paradigm. Classical or operant conditioning is used to measure responses to ambiguous cues, and it has been reported...

Wolfensohn, S., Shotton, J., Bowley, H. et al. 2018. Assessment of welfare in zoo animals: Towards optimum quality of life. Animals 8(7), 110.

Zoos are required to maintain a high standard of animal welfare, and this can be assessed using a combination of resource-based and animal-based indices usually divided into behavioural indicators, physiological indicators and clinical/pathological signs. Modern...

Schiffmann, C., Hoby, S., Wenker, C. et al. 2018. When elephants fall asleep: A literature review on elephant rest with case studies on elephant falling bouts, andpractical solutions for zoo elephants. Zoo Biology 37(3), 133–145.

Little attention has been paid to the resting and sleeping behavior of zoo elephants so far. An important concern is when elephants avoid lying down, due to degenerative joint and foot disease, social structure, or...

French, F., Mancini, C., Sharp, H. 2018. High tech cognitive and acoustic enrichment for captive elephants. Journal of Neuroscience Methods 300, 173-183.

This paper investigates the potential for using technology to support the development of sensory and cognitive enrichment activities for captive elephants. It explores the usefulness of applying conceptual frameworks from interaction design and game design...

Morfeld, K. A., Brown, J.L. 2017. Metabolic health assessment of zoo elephants: Management factors predicting leptin levels and the glucose-to-insulin ratio and their associations with health parameters. PLOS ONE 12(11), e0188701.

Screening for metabolic-related health problems can enhance animal welfare, so the purpose of this study was to conduct the first metabolic health assessment of zoo elephants and use epidemiological methods to determine how factors in...

Chadwick, C. L., Williams, E., Asher, L. et al. 2017. Incorporating stakeholder perspectives into the assessment and provision of captive elephant welfare. Animal Welfare 26(4), 461-472.

Recent concerns over the welfare of elephants in UK zoos have implications for their future in captivity, and it is clear that improvements in welfare should be made. Evidence suggests that the knowledge of experienced...

Krebs, B. L., Torres, E., Chesney, C. et al. 2017. Applying behavioral conditioning to identify anticipatory behaviors. Journal of Applied Animal Welfare Science 20(2), 155-175.

The ability to predict regular events can be adaptive for nonhuman animals living in an otherwise unpredictable environment. Animals may exhibit behavioral changes preceding a predictable event; such changes reflect anticipatory behavior. Anticipatory behavior is...

Alligood, C. A., Dorey, N. R., Mehrkam, L. R. et al. 2017. Applying behavior-analytic methodology to the science and practice of environmental enrichment in zoos and aquariums. Zoo Biology 36(3), 175–185.

Environmental enrichment in zoos and aquariums is often evaluated at two overlapping levels: published research and day‐to‐day institutional record keeping. Several authors have discussed ongoing challenges with small sample sizes in between‐groups zoological research and...

Rose, P. E., Nash, S. M., Riley, L. M. 2017. To pace or not to pace? A review of what abnormal repetitive behavior tells us about zoo animal management. Journal of Veterinary Behavior 20, 11-21.

Performance of abnormal repetitive behavior (ARB) is noted in many captive wild species. ARB can be categorized into 2 basic forms: those whose aim appears to be to compulsively reach an inappropriate goal and those...

Schiffmann, C., Clauss, M., Hoby, S. et al. 2017. Visual body condition scoring in zoo animals – Composite, algorithm and overview approaches. Journal of Zoo and Aquarium Research 5(1), 1-10.

Various body condition scoring (BCS) methods have been developed as management tools in zoo animal husbandry. In contrast to BCS for farm animals, where visual and palpable features are used, these protocols are mainly restricted...

Brown, J. L., Paris, S., Prado-Oviedo, N. A. 2016. Reproductive health assessment of female elephants in North American zoos and association of husbandry practices with reproductive dysfunction in African Elephants (Loxodonta africana). PLOS ONE 11(7), e0145673.

As part of a multi-institutional study of zoo elephant welfare, we evaluated female elephants managed by zoos accredited by the Association of Zoos and Aquariums and applied epidemiological methods to determine what factors in the...

Greco, B. J., Meehan, C. L., Hogan, J. N. et al. 2016. The days and nights of zoo elephants: Using epidemiology to better understand stereotypic behavior of African elephants (Loxodonta africana) and Asian elephants (Elephas maximus) in North American zoos. PLOS ONE 11(7), e0144276.

Stereotypic behavior is an important indicator of compromised welfare. Zoo elephants are documented to perform stereotypic behavior, but the factors that contribute to performance have not been systematically assessed. We collected behavioral data on 89...

Holdgate, M. R., Meehan, C. L., Hogan, J. N. et al. 2016. Walking behavior of zoo elephants: Associations between GPS-measured daily walking distances and environmental factors, social factors, and welfare indicators. PLOS ONE 11(7), e0150331.

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that...

Meehan, C. L., Hogan, J. N., Bonaparte-Saller, M. K. et al. 2016. Housing and social environments of African (Loxodonta africana) and Asian (Elephas maximus) elephants in North American zoos. PLOS ONE 11(7), e0146703.

We evaluated 255 African (Loxodonta africana) and Asian (Elephas maximus) elephants living in 68 North American zoos over one year to quantify housing and social variables. All parameters were quantified for the both the day...

Holdgate, M. R., Meehan, C. L., Hogan, J. N. et al. 2016. Recumbence behavior in zoo elephants: Determination of patterns and frequency of recumbent rest and associated environmental and social factors. PLOS ONE 11(7), e0153301.

Resting behaviors are an essential component of animal welfare but have received little attention in zoological research. African savanna elephant (Loxodonta africana) and Asian elephant (Elephas maximus) rest includes recumbent postures, but no large-scale investigation...

Miller, M. A., Hogan, J. N., Meehan, C. L. 2016. Housing and demographic risk factors impacting foot and musculoskeletal health in African elephants [Loxodonta africana] and Asian elephants [Elephas maximus] in North American zoos. PLOS ONE 11(7), e0155223.

For more than three decades, foot and musculoskeletal conditions have been documented among both Asian [Elephas maximus] and African [Loxodonta africana] elephants in zoos. Although environmental factors have been hypothesized to play a contributing role...

Prado-Oviedo, N. A., Bonaparte-Saller, M. K., Malloy, E. J. et al. 2016. Evaluation of demographics and social life events of Asian (Elephas maximus) and African elephants (Loxodonta africana) in North American zoos. PLOS ONE 11(7), e0154750.

This study quantified social life events hypothesized to affect the welfare of zoo African and Asian elephants, focusing on animals that were part of a large multi-disciplinary, multi-institutional elephant welfare study in North America. Age...

Morfeld, K. A., Meehan, C. L., Hogan, J. N. et al. 2016. Assessment of body condition in African (Loxodonta africana) and Asian (Elephas maximus) elephants in North American zoos and management practices associated with high body condition scores. PLOS ONE 11(7), e0155146.

Obesity has a negative effect on health and welfare of many species, and has been speculated to be a problem for zoo elephants. To address this concern, we assessed the body condition of 240 elephants...

Martin, R. A., Melfi, V. 2016. A comparison of zoo animal behavior in the presence of familiar and unfamiliar people. Journal of Applied Animal Welfare Science 19(3), 234-244.

As recorded in domestic nonhuman animals, regular interactions between animals in zoos and keepers and the resulting relationship formed (human– animal relationship [HAR]) are likely to influence the animals’ behaviors with associated welfare consequences. HAR...