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. 
Bethell, E. J., Koyama, N. F. 2015. Happy hamsters? Enrichment induces positive judgement bias for mildly (but not truly) ambiguous cues to reward and punishment in Mesocricetus auratus. Royal Society Open Science 2, 140399.

Recent developments in the study of animal cognition and emotion have resulted in the ‘judgement bias’ model of animal welfare. Judgement biases describe the way in which changes in affective state are characterized by changes...

Washburn, D. 2015. The four Cs of psychological wellbeing: Lessons from three decades of computer-based environmental enrichment. Animal Behavior and Cognition 2(3), 218–232.

Three decades ago, the Animal Welfare Act was amended to require researchers to provide environments that promoted the psychological, as well as the physical, wellbeing of nonhuman primates maintained for research purposes. We developed a...

Charmoy, K., Sullivan, T., Miller, L. 2015. Impact of different forms of environmental enrichment on foraging and activity levels in gorillas (Gorilla gorilla gorilla). Animal Behavior and Cognition 2(3), 233–240.

The maintenance of species-specific behaviors for animals in zoological institutions is of top priority, as this can help ensure high levels of animal welfare. Strict feeding schedules within institutions can often impact natural foraging behaviors...

Perret, A., Henry, L., Coulon, M. et al. 2015. Social visual contact, a primary “drive” for social animals? Animal Cognition 18(3), 657–666.

Social animals are always searching for conspecifics, thereby expressing a genuine “social need”. This need is illustrated by the fact that social isolation can induce isolation syndromes that can be attenuated by devices such as...

Adamson, T. W., Perez, M.C. 2014. Use of cuttlebones to reduce the incidence of feather pecking in chickens. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 540 (Abstract #PS56).

Feather pecking is a maladaptive behavior where chickens (and other poultry species) peck the feathers of conspecifics and damage the plumage and frequently the skin. It is one of the most common behavioral problems in...

Monts de Oca, N., Diaz, L., McMahen, D. et al. 2014. The use of lean management principles to enhance a nonhuman primate environmental enrichment program. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 580-581. (Abstract #P122).

Sewage back-up and overflows in the rooms of our primate facility initiated an analysis of the factors contributing to the clogging of the drains. An investigation reviewing the materials responsible for the clogging of the...

Rose, A. M., Ferrecchia, C. E., Van Andel, R. 2014. Developing an enrichment plan for water-regulated nonhuman primates. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 565 (Abstract #P60).

Environmental enrichment for nonhuman primates is an essential requirement in laboratory animal research. The Animal Welfare Regulations and the Guide for the Care and Use of Laboratory Animals state that the facility’s enrichment program must...

Daigle, C. L., Rodenburg, T. B., Bolhuis, J. E. et al. 2014. Use of dynamic and rewarding environmental enrichment to alleviate feather pecking in non-cage laying hens. Applied Animal Behaviour Science 161, 75-85.

Feather pecking (FP) can cause feather loss, resulting in physical injuries, which may lead to cannibalism. FP appears to be a redirection of foraging behavior, which intensifies when hens have difficulty coping with stress and...

Willey, S. 2014. Nonhuman primate enrichment room planning, design, and use. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 539 (Abstract #PS52).

Princeton University continually makes efforts to improve and enhance the quality of life of our NHPs used in research. A part of this effort is to continue to improve our environmental enrichment program, promoting the...

Qi, K., De-mi, S., Chuan, Q. 2014. Current understanding and use of environmental enrichment in China. Enrichment Record 20, 8-11.

In practice, consideration is given to providing most of the species used in research,testing and education withsome level of environmental enrichment. However, although the current level of awareness and understanding about the benefits of environmental...

Rommers, J. M., Reuvekamp, B. J. F., Gunnink, H. et al. 2014. Effect of hiding places, straw and territory on aggression in group-housed rabbit does. Applied Animal Behaviour Science 157, 117-126.

Group-housing of rabbit does may be preferred from welfare point of view. However, group-housing causes agonistic behaviour which may cause severe injuries. Severe injuries may be prevented by offering hiding places for attacked does. Providing...

Nicholson, G., Sheldon, E. L., Hamilton, J. et al. 2014. Sand pools as a novel enrichment for rabbits. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 571. (Abstract #P83).

For anyone who has housed rabbits in an artificial plastic environment, what to provide as a nonfood enrichment can be an issue. Nonfood enrichment, or environmental enrichment, can be any toy, engaging sights or sounds...

Lidfors, L., Wichman, A., Ewaldsson, B. et al. 2014. Enriched cages for groups of laboratory male rats and their effects on behaviour, weight gain and adrenal glands. Laboratory Animals 48, 36-49.

We investigated if there were any negative effects on the behaviour and physiology of rats housed in groups of five in two types of enriched cages and compared them with paired-housed rats housed in traditional...

Escribano, B., Quero, I., Feijóo, M. et al. 2014. Role of noise and music as anxiety modulators: Relationship with ovarian hormones in the rat. Applied Animal Behaviour Science 152, 73-82.

This work aims to verify the role of noise and music as anxiety modulators and their relationship with ovarian hormones. For this purpose, female Wistar rats were used and treated, forming different experimental groups, with...

Ditewig, A. C., Bratcher, N. A., Davila, D. R. et al. 2014. Enrichment with wood blocks does not affect toxicity assessment in an exploratory toxicology model using Sprague-Dawley rats. JAALAS 53(3), 246-260.

Environmental enrichment in rodents may improve animal well-being but can affect neurologic development, immune system function, and aging. We tested the hypothesis that wood block enrichment affects the interpretation of traditional and transcriptomic endpoints in...

Callan, T. 2014. Primates Presents. Enrichment Record 18, 5-6.

In the world of enrichment, ideas can be limitless. Sometimes, you just have to think outside the box... or in this case, "inside the box"! Who doesn't love a present with the colorful exterior and...

Hori, M., Yamada, K., Ohnishi, J. et al. 2014. Tickling during adolescence alters fear-related and cognitive behaviors in rats after prolonged isolation. Physiology & Behavior 131, 62-67.

Social interactions during adolescence are important especially for neuronal development and behavior. We recently showed that positive emotions induced by repeated tickling could modulate fear-related behaviors and sympatho-adrenal stress responses. In the present study, we...

Sharp, J., Azar, T., Lawson, D. 2014. Effects of a complex housing environment on heart rate and blood pressure of rats at rest and after stressful challenges. JAALAS 53(1), 52-60.

Housing enrichment for rodents continues to be a discussion topic within the animal care community. The objective of this study was to determine the extent to which a complex housing environment affects heart rate, blood...

Abou-Ismail, U. A., Darwish, R. A., Ramadan, S. G. A. 2014. Should cages of laboratory rats be enriched physically or socially? Global Veterinaria 13(4), 570-582.

Experiments of environmental enrichment usually compare between group-housed rats in enriched and unenriched cages or between group-housed rats in enriched cages and single-housed rats in unenriched cages. This bias is mainly to maximize the chance...

Alworth, L. C., Buerkle, S. C. 2013. The effects of music on animal physiology, behavior and welfare. Lab Animal 42(2), 54-61.

Physiological and psychological effects of listening to music have been documented in humans. The changes in physiology, cognition and brain chemistry and morphology induced by music have been studied in animal models, providing evidence that...

Reinhardt, V. (ed.) 2013. Compassion Makes a Difference - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume III. Animal Welfare Institute, Washington, DC.

This is the third volume of discussions that took place on the Laboratory Animal Refinement & Enrichment Forum (LAREF). This forum is dedicated to the exchange of personal experiences of refining the conditions under which...

Pierre, P. J., Torres, N. A., Rosga, M. D. et al. 2013. Colony-wide assessment of the foraging devices: Refinement of delivery practices, cost and the caloric content delivered via foraging devices. American Journal of Primatology 75(S1), 82. (36th Meeting of the American Society of Primatologists Scientific Program, Abstract #163)

Foraging opportunities are a key component of enrichment in captive nonhuman primates (NHP) providing manipulative opportunities in which animals can engage in species-typical behaviors. Recent studies suggest captive NHP populations have increased body weight over...

Wren, M. A., Dauchy, R. T., Hill, S. M. et al. 2013. Colored enrichment devices influence behavior and circadian metabolism and physiology in Sprague-Dawley rats. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 608 (Abstract #PS2).

Enrichment devices and strategies, as currently endorsed by the Guide, are used to improve laboratory animal health and wellbeing. Many conclusions supporting this premise, however, are based primarily on observational studies with minimal consideration for...

Wasko, K., Acklin, C. J. 2013. Fresh façades for rodent homes: Revisiting enrichment naturally. Enrichment Record 16, 9-11.

Currently, enrichment consists of a variety of plastic toys to promote natural behaviors, but why use artificial devices when you could use natural materials like the animals experience in their native environment? ... From these...

Hrapkiewicz, K., Colby, L. A., Denison, P. 2013. Clinical Laboratory Animal Medicine: An Introduction (4th Ed). Wiley-Blackwell, Ames, IA.

Clinical Laboratory Animal Medicine: An Introduction, Fourth Edition offers a user-friendly guide to the unique anatomy and physiology, care, common diseases, and treatment of small mammals and nonhuman primates. Carefully designed for ease of use...