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. 
Ojelade, O. C., Durosaro, S. O., Akinde, A. O. et al. 2022. Environmental enrichment improves the growth rate, behavioral and physiological response of juveniles of Clarias gariepinus under laboratory conditions. Frontiers in Veterinary Science 9, 980364.

Environmental enrichment (EE) improves the growth rate and welfare of some cultured fishes. However, most cultured fish species are raised in non-enriched housing conditions. Clarias gariepinus is an important commercial fish species, but little is...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Corredor, K., Marín, D. P., García, C. C. et al. 2022. Providing environmental enrichment without altering behavior in male and female Wistar rats (Rattus norvegicus). JAALAS 61(3), 234-240.

In research using animal models, subjects are commonly maintained under standard housing conditions, mainly because of the idea that enhancing welfare conditions could alter experimental data. Another common practice in many laboratories relates to the...

Sanders, K., Fernandez, E. J. 2022. Behavioral implications of enrichment for golden lion tamarins: A tool for ex situ conservation. Journal of Applied Animal Welfare Science 25(3), 214-223.

The re-release of golden lion tamarins (Leontopithecus rosalia), from zoos into the wild, is considered to be an ex situ conservation success story. However, zoo-born golden lion tamarins have lower survival rates than their wild-born...

de França Santos, M., de Menezes Galvão, A. C., Santos Silva, F. et al. 2022. Welfare improvement by enrichment programs in common marmoset females under social isolation. Journal of Applied Animal Welfare Science 25(3), 297-309.

Animal welfare is critical to buffer stress in captive animals and to ensure the reliability of data from studies. The most usual environmental enrichment technique (EE) for social non-human primates is the social enrichment. However...

Hurley, A., Cotton, A. 2022. Foraging enrichment affects behaviour and enclosure utilisation in captive male gelada Theropithecus gelada. Journal of Zoo and Aquarium Research 10(3), 129-138.

Enrichment devices are important tools to engage zoo-housed animals in species-specific natural behaviours, which is critical to ensure animal welfare. The gelada Theropithecus gelada has a unique graminivorous feeding ecology, yet there is minimal enrichment...

Chesler, K. C., Motz, C. T., Bales, K. L. et al. 2022. Voluntary oral dosing for precise experimental compound delivery in adult rats. Laboratory Animals 56(2), 147-156.

Preclinical drug studies routinely administer experimental compounds to animal models with the goal of minimizing potential adverse events from the procedure. In this study, we assessed the ability to train adult male Long Evans rats...

Neto, T., Faustino-Rocha, A. I., Gil da Costa, R. M. et al. 2022. A quick and low-intensity method for oral administration to large numbers of mice: A possible alternative to oral gavage. Laboratory Animals 56(2), 185-190.

Oral administration of medication to experimental animals is a cause of significant stress. When coupled to animals who are already under strenuous circumstances due to the disease being modelled, there is a significant risk for...

Hinchcliffe, J. K., Jackson, M. G., Robinson, E. S. 2022. The use of ball pits and playpens in laboratory Lister Hooded male rats induces ultrasonic vocalisations indicating a more positive affective state and can reduce the welfare impacts of aversive procedures. Laboratory Animals 56(4), 370-379.

The advancement and quality of science rely on research that is robust and unbiased in its experimental design, execution, analysis, and reproducibility. In preclinical research, a better understanding of animal emotions and refinement of their...

Ramírez-Rodríguez, G. B., Gutiérrez-Vera, B., Ortiz-López, L. et al. 2022. Environmental enrichment: Dissociated effects between physical activity and changing environmental complexity on anxiety and neurogenesis in adult male Balb/C mice. Physiology & Behavior 254, 113878.

Several factors, including environmental modifications, stimulate neuroplasticity. One type of neuroplasticity consists in the generation of new neurons in the dentate gyrus of the hippocampus. Neurogenesis is modulated by environmental enrichment (ENR, tunnels plus running...

Spitzer, H. B., Meagher, R. K., Proudfoot, K. L. 2022. The impact of providing hiding spaces to farmed animals: A scoping review. PLOS ONE 17(11), e0277665.

Many wild animals perform hiding behaviours for a variety of reasons, such as evading predators or other conspecifics. Unlike their wild counterparts, farmed animals often live in relatively barren environments without the opportunity to hide...

Padrell, M., Amici, F., Córdoba, M. P. et al. 2022. Cognitive enrichment in a social setting: Assessing the use of a novel food maze in sanctuary-housed chimpanzees. Primates 63(5), 509–524.

Foraging devices are effective enrichment tools for non-human primates, as they provide both cognitive and manipulative stimulation that may enhance these animals’ welfare. We assessed the behavioral effects of a novel tool-based enrichment on 14...

Butler, S. 2022. Gardening for Gorillas. Orla Kelly Publishing, Dublin, Ireland. 369 p.

During the author's 37 years as Curator of Horticulture, Dublin Zoo transformed from an almost Victorian appearance to a verdant green ark. A progressive masterplan focused on animal welfare and themed habitats reflects the spirit...

Córneo, E., Michels, M., Abatti, M. et al. 2022. Enriched environment causes epigenetic changes in hippocampus and improves long-term cognitive function in sepsis. Scientific Reports 12(1), 11529.

Sepsis is defined as a life-threatening organ dysfunction caused by an inappropriate host response to infection. The presence of oxidative stress and inflammatory mediators in sepsis leads to dysregulated gene expression, leading to a hyperinflammatory...

Caselli, M., Messeri, P., Dessì-Fulgheri, F. et al. 2022. Enriching zoo-housed ring-tailed lemurs (Lemur catta): Assessing the influence of three types of environmental enrichment on behavior. Animals 12(20), 2836.

Environmental enrichment is a management tool used to promote positive animal welfare by stimulating species-specific behaviors and providing animals with opportunities to exert choice and control over the environment. Our study aimed to evaluate the...

Chrzanowska, A., Modlinska, K., Goncikowska, K. et al. 2022. Rat’s response to a novelty and increased complexity of the environment resulting from the introduction of movable vs. stationary objects in the free exploration test. PLOS ONE 17(12), e0279006.

Most animals, including rats, show a preference for more complex environments. This is demonstrated particularly well when complexity increases due to the addition of new elements to the environment. The aim of the study was...

Fink, L. B., Mukobi, A., Gruber, L. et al. 2022. Longitudinal analysis of variability in fecal glucocorticoid metabolite concentrations in three orangutans (Pongo pygmaeus pygmaeus and Pongo pygmaeus abelii) before, during, and after transition from a regular habitat environment to temporary housing in indoor holding facilities. Animals 12(23), 3303.

Considerable research has been conducted on the effects of inter-institutional transfers, but far less consideration has been given to intra-institutional transfers and extended housing in off-habitat holding. On 15 May 2018, The Oregon Zoo’s orangutans...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Ojelade, O. C., Durosaro, S. O., Akinde, A. O. et al. 2022. Environmental enrichment improves the growth rate, behavioral and physiological response of juveniles of Clarias gariepinus under laboratory conditions. Frontiers in Veterinary Science 9, 980364.

Environmental enrichment (EE) improves the growth rate and welfare of some cultured fishes. However, most cultured fish species are raised in non-enriched housing conditions. Clarias gariepinus is an important commercial fish species, but little is...

Riva, M. G., Sobrero, L., Menchetti, L. et al. 2022. Unhandled horses classified with broken/unbroken test (BUT) exhibit longer avoidance, flight reactions, and displacement behaviors when approached by humans. Frontiers in Veterinary Science 9, 1022255.

Horses with a low level of tameness are at higher risk for transport-related disease and injury; hence, European regulations for the protection of animals during transport (EC 1/2005) are stricter for unhandled (unbroken) horses. However...

Weir, R. 2022. The effects of various enrichment methods on the engagement nd inter-group behaviour of captive chacma baboons. Canopy 23(1), 4–6.

The goal of this study was to answer two research questions: (1) how important is it to rotate enrichment types to maintain high levels of engagement in individually-housed adult chacma baboons? and (2) which methods...

Yamanashi, Y., Hitoosa, K., Yoshida, N. et al. 2022. Do chimpanzees enjoy a virtual forest? A pilot investigation of the use of interactive art as a form of environmental enrichment for zoo-housed chimpanzees. American Journal of Primatology 84(10), e23343.

Environmental enrichment is essential for the well-being of zoo animals. Recent advances in sensor and video technologies may contribute to improvements in enrichment in terms of their flexibilities and time constraints. The purpose of this...

Cait, J., Cait, A., Scott, R. W. et al. 2022. Conventional laboratory housing increases morbidity and mortality in research rodents: Results of a meta-analysis. BMC Biology 20(1), 15.

Over 120 million mice and rats are used annually in research, conventionally housed in shoebox-sized cages that restrict natural behaviours (e.g. nesting and burrowing). This can reduce physical fitness, impair thermoregulation and reduce welfare (e.g...

Lee, W.-Y., Lan, K.-W., Chang, H.-H. et al. 2022. Residency and swimming behavior of Acanthopagrus schlegelii, Trachinotus blochii, and Acanthopagrus latus in relation to artificial reef models in a captivity experiment. Applied Animal Behaviour Science 257, 105778.

Global capture fisheries production has declined rapidly over the past decades because of the growing demand for fisheries resources. To restore fisheries resources, artificial reefs (ARs) are deployed on the seafloor to provide new habitats...

Molina, S. J., Lietti, Á. E., Carreira Caro, C. S. et al. 2022. Effects of early noise exposure on hippocampal-dependent behaviors during adolescence in male rats: Influence of different housing conditions. Animal Cognition 25(1), 103–120.

Central nervous system (CNS) development is a very complex process that can be altered by environmental stimuli such as noise, which can generate long-term auditory and/or extra-auditory impairments. We have previously reported that early noise...