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. 
Garcia, T., Brown, C., Margolies, D. et al. 2021. Grinding on a last nerve: Attempting to curb food grinding in mice. Laboratory Animal Science Professional 9(6) (November/December), 34-36.

Food grinding, or chewing food without ingestion, is a topic of interest in the laboratory animal community. In addition to increased effort needed to deal with this excess waste and provide suitable microenvironment for animals...

Brooks, J., Yoshimura, H., Taki, Y. 2021. Knowledge-based enrichment: Development of a novel enrichment device for captive chimpanzees. Zoo Biology 40(5), 398-406.

The field of environmental enrichment has grown considerably, but most enrichment is still focused on tasks where highly valued food rewards are directly visible. We designed a device which would instead make use of knowledge...

Ratuski, A. S., Makowska, I. J., Dvorack, K. R. et al. 2021. Using approach latency and anticipatory behaviour to assess whether voluntary playpen access is rewarding to laboratory mice. Scientific Reports 11(1), 18683.

Laboratory mice are typically housed in “shoebox" cages that limit the expression of natural behaviours. Temporary access to more complex environments (playpens) may improve their welfare. We aimed to assess if access to playpens is...

Kawamura, G., Yong, A. S. K., Roy, D. C. et al. 2020. Shelter colour preference in the purple mud crab Scylla tranquebarica (Fabricius). Applied Animal Behaviour Science 225, 104966.

Cannibalism a serious problem in the grow-out of mud crabs in ponds. Studies have proven that presence of shelters decreases aggressive behaviour of Scylla spp. in ponds and tanks. In this study, the shelter colour...

Matsuzawa, T. 2020. WISH cages: Constructing multiple habitats for captive chimpanzees. Primates 61(2), 139–148.

This article aims to introduce environmental enrichment for captive chimpanzees in Japan in a historical context. It describes the most recent endeavor of constructing huge cages and connecting multiple habitats. The Ai Project, a series...

Regaiolli, B., Angelosante, C., Marliani, G. et al. 2020. Gum feeder as environmental enrichment for zoo marmosets and tamarins. Zoo Biology 39(2), 73-82.

Tamarins and marmosets are small-bodied social callitrichines. Wild callitrichines feed on exudates, such as sap and gum; particularly, marmosets are mainly gummivores, while tamarins consume gums only occasionally and opportunistically. Zoo marmosets and tamarins are...

Ebel, S. J., Kopp, K. S., Liebal, K. 2020. Object preferences in captive Sumatran orang-utans (Pongo abelii). Behavioural Processes 170, 103993.

While preferences for perceptual features of objects are well studied in humans, little is known about this trait in other great apes. We therefore presented captive Sumatran orang-utans (Pongo abelii) with objects that differed in...

Mertens, S., Gass, P., Palme, R. et al. 2020. Effect of a partial cage dividing enrichment on aggression-associated parameters in group-housed male C57BL/6NCrl mice. Applied Animal Behaviour Science 224, 104939.

Group-housing is highly important for social animals. Group-housing of male mice in captivity though often leads to aggression with partially disastrous consequences for the animals as well as for the quality of experimental data. In...

McAllister, B. B., Thackray, S. E., Garciá de la Orta, B. K. et al. 2020. Effects of enriched housing on the neuronal morphology of mice that lack zinc transporter 3 (ZnT3) and vesicular zinc. Behavioural Brain Research 379, 112336.

In the central nervous system, certain neurons store zinc within the synaptic vesicles of their axon terminals. This vesicular zinc can then be released in an activity-dependent fashion as an intercellular signal. The functions of...

Crawford, L. E., Knouse, L. E., Kent, M. et al. 2020. Enriched environment exposure accelerates rodent driving skills. Behavioural Brain Research 378, 112309.

Although rarely used, long-term behavioral training protocols provide opportunities to shape complex skills in rodent laboratory investigations that incorporate cognitive, motor, visuospatial and temporal functions to achieve desired goals. In the current study, following preliminary...

Qu, C., Xu, L., Shen, J. et al. 2020. Protection of blood-brain barrier as a potential mechanism for enriched environments to improve cognitive impairment caused by chronic cerebral hypoperfusion. Behavioural Brain Research 379, 112385.

Chronic cerebral hypoperfusion (CCH) is a common pathophysiological basis for Alzheimer’s Disease and vascular dementia in the early stages. It has been confirmed that blood-brain barrier (BBB) destruction is a key factor in CCH-related cognitive...

Menezes, J., Souto das Neves, B.-H., Gonçalves, R. et al. 2020. Maternal deprivation impairs memory and cognitive flexibility, effect that is avoided by environmental enrichment. Behavioural Brain Research 381, 112468.

Maternal deprivation (MD) causes cognitive deficits that persist until adulthood. Thereby, the environmental enrichment (EE) is widely used to increase brain plasticity. Here, pregnant female rats were used and their offspring were submitted to neonatal...

Alemán-Laporte, J., Bandini, L. A., Garcia-Gomes, M. S. et al. 2020. Combination of ketamine and xylazine with opioids and acepromazine in rats: Physiological changes and their analgesic effect analysed by ultrasonic vocalization. Laboratory Animals 54(2), 171–182.

In this study, the effect of four anaesthetic protocols that included the combination of xylazine (X) and ketamine (K) with acepromazine (A) and opioids (methadone (Me), morphine (Mo) or tramadol (T)) was evaluated in laboratory...

Wendler, P., Ertl, N., Flügger, M. et al. 2020. Influencing factors on the foot health of captive Asian elephants (Elephas maximus) in European zoos. Zoo Biology 39(2), 109-120.

Pathological lesions of feet occur frequently in captive elephant populations. To improve foot health, it is important to identify risk factors associated with such pathologies. Several previous studies have analyzed potentially influencing factors but were...

Brown, J. L., Bansiddhi, P., Khonmee, J. et al. 2020. Commonalities in management and husbandry factors important for health and welfare of captive elephants in North America and Thailand. Animals 10(4), 737.

This review paper is a synthesis of results from multiple studies that we have conducted over the past several years using similar methodologies to identify factors related to welfare of captive populations of elephants in...

Inoue, N., Shimada, M. 2020. Comparisons of activity budgets, interactions, and social structures in captive and wild chimpanzees (Pan troglodytes). Animals 10(6), 1063.

Chimpanzees in zoos with sufficient and appropriate environmental enrichment devices are expected to exhibit behaviors, interactions, and societies similar to those in the wild. In this study, we compared the activity budgets of each observed...

Forrest, G., Sattar, A., Evenden, P. et al. 2020. A sweet change to the needle. Animal Technology and Welfare 19(1), 73-75.

The Named Veterinary Surgeon (NVS) at the Royal Veterinary College in London suggested providing post-operative pain relief (carprofen) to rats in raspberry flavoured jelly to avoid the use of s.c. injections. This article provides a...

Watson, H. A study into viable wooden enrichment objects for Syrian hamsters. Animal Technology and Welfare 19(1), 86-88.

Failing to provide hamsters with a method to wear down their teeth can lead to detrimental behaviour such as bar chewing, and health issues, for example, overgrown teeth and tooth loss. However, hamsters use their...

Oralman, T. 2020. Confronting crunching: A refinement for the care of mice with the desire to crunch. Animal Technology and Welfare 19(1), 89-91.

‘Crunching’ is the term often used to describe the abnormal behaviour of mice that habitually crunch their pelleted diet, causing substrate levels to rise as the crumbs settle on the cage floor ultimately burying the...

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...

Gjendal, K., Ottesen, J. L., Olsson, I. et al. 2020. Effect of repeated exposure to isoflurane on nest building and burrowing in mice. JAALAS 59(1), 30–36.

Nest building and burrowing are highly motivated natural behaviors in rodents, and changes in these behaviors can serve as welfare assessment tools. In this study, we investigated: 1) the limits of agreement between 2 observers...

Brekke, J., Scholz, J. 2020. Just hanging out: Elevating rat enrichment in small spaces. Laboratory Animal Science Professional 8(3) (May/June), 40-42.

This article describes how an Animal Care Technician at Mayo Clinic Rochester campus designed and created a novel enrichment item for rats: a ‘hammock’ made of PVC tunnels hung onto the lid of standard laboratory...

Buchanan, K. 2020. DIY: Foraging balls. Laboratory Animal Science Professional 8(3) (May/June), 51.

This article describes the steps for making a DIY guinea pig or rabbit cardboard foraging ball. Pictures are provided for each step as well as the completed ball. These cardboard foraging balls can be made...

Blok, J., Black, D. A., Petersen, J. et al. 2020. Environmental enrichment rescues visually-mediated behavior in Ten-m3 knockout mice during an early critical period. Frontiers in Behavioral Neuroscience 14, 22.

Environmental enrichment (EE) has been shown to promote neural plasticity. Its capacity to induce functional repair in models which exhibit profound sensory deficits due to aberrant axonal guidance has not been well-characterized. Ten-m3 knockout (KO)...

Tang, W., Zillmann, U., Sprengel, R. 2020. Alternative anesthesia of neonatal mice for global rAAV delivery in the brain with non-detectable behavioral interference in adults. Frontiers in Behavioral Neuroscience 14, 115.

Viral-transduced gene expression is the current standard for cell-type-specific labeling and cell tacking in experimental neuroscience. To achieve widespread gene expression, a viral delivery method to neonatal rodents was introduced more than two decades ago...