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. 
Dinets, V. 2015. Play behavior in crocodilians. Animal Behavior and Cognition 2(1), 49–55.

Play behavior in crocodilians is not uncommon, but it remains virtually undescribed in scientific literature. I present the first overview of play behavior of three types (locomotor play, object play and social play) in crocodilians...

Buijs, S., Hermans, K., Maertens, L. et al. 2014. Effects of semi-group housing and floor type on pododermatitis, spinal deformation, and bone quality in rabbit does. Animal 8(10), 1728-1734.

The most common housing system for reproduction rabbits, individual cage housing on a wire floor, is increasingly scrutinized because of its potential detrimental impact on animal welfare. We compared three types of housing: (1) individual...

Himmler, B.T., Kisko, T.M., Euston, D.R. et al. 2014. Are 50-kHz calls used as play signals in the playful interaction of rats? I. Evidence from the timing and context of their use. Behavioural Processes 106, 60-66.

During playful interactions, rats emit increased levels of 50-kHz vocalizations. It is possible that these vocalizations are used as play signals that promote and maintain playful contact. The study investigated this possibility. It was predicted...

Baszczak, J. A. 2014. An easy solution for social housing larger guinea pigs in research. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 565 (Abstract #P61).

The standard microisolation caging for guinea pigs, Cavia porcellus, allows for group housing up to a combined weight of 350 g. However, as mandated by the USDA, research facilities must socially house guinea pigs with...

Dorman, B., Weir, D. E. 2014. From swinging single to peacefully cohabitating: A DIY way to managing rabbit socialization without breaking your budget. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 563 (Abstract #P54).

The Guide for the Care and Use of Laboratory Animals requires that all animals, without veterinary or study exemptions, be socially housed. Our current caging only allows enough floor space to house one large rabbit...

Cikanek, S. J., Nockold, S., Brown, J. L. et al. 2014. Evaluating group housing strategies for the ex-situ conservation of harlequin frogs (Atelopus spp) using behavioral and physiological indicators. PLOS ONE 9(2), e90218.

We have established ex situ assurance colonies of two endangered Panamanian harlequin frogs, Atelopus certus and Atelopus glyphus, but observed that males fought with each other when housed as a group. Housing frogs individually eliminated...

McCrossin, F. G. 2014. The effect of pair housing on the aye-aye (Daubentonia madagascariensis). American Journal of Primatology 76(S1), 54. (37th Meeting of the American Society of Primatologists Scientific Program, Abstract #52)

Aye-ayes (Daubentonia madagascariensis) are thought to be solitary animals and are often housed alone in captivity. However, for all primates sociality is known to play a major role in psychological well-being. Captive animals can develop...

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...

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...

Bartal, I. B.-A., Rodgers, D. A., Sarria, M. S. et al. 2014. Pro-social behavior in rats is modulated by social experience. eLife 3, e01385.

In mammals, helping is preferentially provided to members of one’s own group. Yet, it remains unclear how social experience shapes pro-social motivation. We found that rats helped trapped strangers by releasing them from a restrainer...

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...

Krügel, U., Fischer, J., Bauer, K. et al. 2014. The impact of social isolation on immunological parameters in rats. Archives of Toxicology 88(3), 853-855.

In various toxicological studies, single housing of rodents is preferred to standardize for regulatory purposes. However, housing conditions can have severe, often underestimated, impact on results in toxicological examinations. As different husbandry conditions have been...

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...

Turner, P. V., Sunohara-Neilson, J., Ovari, J. et al. 2014. Effects of single compared with pair housing on hypothalamic-pituitary-adrenal axis activation and low-dose heroin place conditioning in adult male Sprague-Dawley rats. JAALAS 53(2), 161-167.

Whether social isolation of adult rats under standard laboratory conditions produces significant long-term alterations in behavior and physiology is unclear. In the present study, male Sprague–Dawley rats were singly or paired-housed for 10 wk. During...

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...

Melotti, L., Bailoo, J., Murphy, E. et al. 2014. Play in rats: Association across contexts and types, and analysis of structure. Animal Behavior and Cognition 1(4), 489–501.

Play has been proposed as a promising indicator of positive animal welfare. We aimed to study play in rats across contexts (conspecific/heterospecific) and types (social: pinning, being pinned; solitary: scampering), and we investigated its structure...

Szendrö, Z., Mikó, A., Odermatt, M. et al. 2013. Comparison of performance and welfare of single-caged and group-housed rabbit does. Animal 7(3), 463-468.

Although rabbit does are generally single housed on rabbit farms worldwide, it has been suggested by some specialists and recommendation of organic rabbit production systems that group housing of does is more comfortable and similar...

Bergman, T. J., Sheehan, M. J. 2013. Social knowledge and signal in primates. American Journal of Primatology 75(7), 683-694.

Primates are notable for having a rich and detailed understanding of their social environment and there has been great interest in the evolution and function of social knowledge in primates. Indeed, primates have been shown...

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...

Less, E. H., Kuhar, C. W., Lukas, K. E. 2013. Assessing the prevalence and characteristics of hair-plucking behaviour in captive western lowland gorillas (Gorilla gorilla gorilla). Animal Welfare 22(2), 175-193.

Non-human primates occasionally exhibit behaviours thought to occur only in captivity that are considered abnormal. In particular, hair-plucking behaviour occurs across many species of mammals and birds. This study was the first to assess the...

Young, L., Lin, R. 2013. Strategies to in increase compatibility among pair-housed rabbits. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 667 (Abstract #P168).

The eighth edition of the Guide for the Care and Use of Laboratory Animals (the Guide) states that appropriate social interaction among members of the same species is essential for normal animal development and wellbeing...

Winnicker, C. 2013. Challenges and opportunities of implementing EU standards for social housing of rodents. Enrichment Record 15, 3-4.

The EU Directive on the protection of animals used for scientific purposes specifically states: Animals, except those which are naturally solitary, shall be socially housed in stable groups of compatible individuals. Even in cases where...

Valuska, A. J., Mench, J. A. 2013. Size does matter: The effect of enclosure size on aggression and affiliation between female New Zealand White rabbits during mixing. Applied Animal Behaviour Science 149(1-4), 72-76.

Social enrichment is increasingly employed to improve the welfare of laboratory animals, including rabbits. However, the high levels of injurious aggression that can occur when unfamiliar adult rabbits are introduced to one another are a...

Scott, J. A., Taylor, D. 2013. Effects of environment and enrichment on the behavior and serum corticosterone levels in Xenopus laevis. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 662 (Abstract #P145).

Xenopus laevis is a commonly used research animal for which well accepted enrichment strategies have not been established. Our overall objective was to identify enrichment strategies that are most beneficial to Xenopus as a step...

Savage, S. 2013. Kidding around in the laboratory animal facility - Goat enrichment. Enrichment Record 14, 14-15.

Goat enrichment can be incredibly rewarding, not only for the goat, but for personnel as well. In our facility, we often refer to goatenrichment tasks as technician (or vet!) enrichment. Somewhere in the evolutionary development...