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. 
Lupfer, G., Brandenburger, A., Machado, M. et al. 2023. Ultrasonic vocalizations near 30 kHz may indicate excitement rather than distress in female Wistar rats. Applied Animal Behaviour Science 261, 105881.

Rats emit ultrasonic vocalizations (USVs), sometimes referred to as 50-kHz vocalizations, during activities such as play and lower-frequency USVs, sometimes referred to as 22-kHz vocalizations, when experiencing distress. Definitions of 22-kHz vocalizations vary in terms...

Broadfoot, C. K., Lenell, C., Kelm-Nelson, C. A. et al. 2023. Effects of social isolation on 50-kHz ultrasonic vocalizations, affective state, cognition, and neurotransmitter concentrations in the ventral tegmental and locus coeruleus of adult rats. Behavioural Brain Research 437, 114157.

Vocal communication, cognition, and affective state are key features of sustained health and wellness, and because vocalizations are often socially-motivated, social experience likely plays a role in these behaviors. The monoaminergic systems of the ventral...

Núñez-Murrieta, M. A., Coria-Avila, G. A., Martínez, A. J. et al. 2023. Preterm rat survival is enhanced by gestational environmental enrichment. Behavioural Processes 205, 104820.

Throughout the last decade, the estimated global human preterm birth rate was 10.6 %, with higher rates in Asia, South America, and Africa. Preterm individuals, even in adulthood, are more likely to develop cardiorespiratory, renal...

Shanazz, K., Nalloor, R., Vazdarjanova, A. 2023. A mild stressor induces short-term anxiety and long-term phenotypic changes in trauma-related behavior in female rats. Frontiers in Behavioral Neuroscience 17.

IntroductionAnxiety and anxiety-influenced disorders are sexually dimorphic with women being disproportionately affected compared to men. Given the increased prevalence in women and the documented differences in anxiety and trauma behavior between male and female rats...

Zevnik, B., Jerchow, B., Buch, T. 2022. 3R measures in facilities for the production of genetically modified rodents. Lab Animal 51(6), 162-177.

Sociocultural changes in the human–animal relationship have led to increasing demands for animal welfare in biomedical research. The 3R concept is the basis for bringing this demand into practice: Replace animal experiments with alternatives where...

Tivey, E. K. L., Martin, J. E., Brown, S. M. et al. 2022. Sex differences in 50 kHz call subtypes emitted during tickling-induced playful behaviour in rats. Scientific Reports 12(1), 15323.

‘Tickling’ induces positive affective states in laboratory rats as evidenced by the production of 50-kHz ultrasonic vocalisations (USVs), although this has mostly been investigated in males. Juvenile rats emit distinctive 50-kHz USV subtypes. Frequency-modulated (FM)...

Hatcher, N. 2022. The effects of enrichment on an abnormal behaviour in naked mole rats (Heterocephalus glaber) at Tilgate Nature Centre. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 49(4), 15-18.

The naked mole rat (Heterocephalus glaber) is a relatively rare mammal in zoological collections with only nine zoos in the United Kingdom holding colonies of varying sizes at the time of study. This study aims...

Sørensen, D., Cloutier, S., Gaskill, B. (Eds.). 2021. Animal-centric Care and Management - Enhancing Refinement in Biomedical Research. CRC Press, Boca Raton, FL.

The concept of the 3Rs (Refinement, Reduction and Replacement) has been used as a framework for improving the welfare of laboratory animals for the last half century. By establishing an animal-centric view on housing and...

Seidisarouei, M., van Gurp, S., Pranic, N. M. et al. 2021. Distinct profiles of 50 kHz vocalizations differentiate between social versus non-social reward approach and consumption. Frontiers in Behavioral Neuroscience 15, 693698.

Social animals tend to possess an elaborate vocal communication repertoire, and rats are no exception. Rats utilize ultrasonic vocalizations (USVs) to communicate information about a wide range of socially relevant cues, as well as information...

Ypsilantis, P., Souftas, V., Vyza, V. et al. 2021. Magnetic resonance imaging for early pregnancy diagnosis in the laboratory rat. Laboratory Animals 55(3), 262-269.

Pregnancy diagnosis and embryo counting are important end points in reproductive, developmental biology and toxicology studies. The purpose of the present study was to assess the feasibility and efficacy of magnetic resonance imaging (MRI) for...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Henderson, S. 2020. Development of a sifting cage change method for rats to improve welfare. Animal Technology and Welfare 19(2), 145-148.

This poster describes the development of a sifting cage change method for rats to improve welfare. I came up with the idea after seeing how skittish and stressed the rats in my unit were and...

King, J. 2018. Report of the Enrichment; Awareness and Uptake Workshop 2018 on 26th June at College Court, Leicester. Animal Technology and Wefare 17(3), 163-167. [Meeting Report]

The point of the session was to have a collaborative discussion about environmental enrichment. The organisers wanted to know people’s experiences with enrichment, the barriers they have faced, if they have overcome any, and also...

King, J. 2019. Team awesome: Why we can be proud. Animal Technology and Welfare 18(2), 127-131.

The presentation I gave at IAT Congress 2019 was based on the changes and refinements the University of Dundee, Medical School Resource Unit (MSRU) has made over the past 18 months. These changes, described in...

Brudzynski, S. M. 2019. Emission of 22 kHz vocalizations in rats as an evolutionary equivalent of human crying: Relationship to depression. Behavioural Brain Research 363, 1-12.

There is no clear relationship between crying and depression based on human neuropsychiatric observations. This situation originates from lack of suitable animal models of human crying. In the present article, an attempt will be made...

Stramek, A. K., Johnson, M. L., Taylor, V. J. 2019. Improved timed-mating, non-invasive method using fewer unproven female rats with pregnancy validation via early body mass increases. Laboratory Animals 53(2), 148–159.

For studies requiring accurate conception-timing, reliable, efficient methods of detecting oestrus reduce time and costs, whilst improving welfare. Standard methods use vaginal cytology to stage cycle, and breeders are paired-up using approximately five proven females...

McMillan, F. D. (ed). 2019. Mental Health and Well-being in Animals (2nd ed). CABI, Wallingford, UK.

This second edition is fully revised, expanded, and comprehensively updated with the most current knowledge about the full array of mental health issues seen in animals. Written by key opinion leaders, internationally-recognized experts and specialists...

Wang, R., Hausknechta, K. A., Haj-Dahmane, S. et al. 2018. Decreased environmental complexity during development impairs habituation of reinforcer effectiveness of sensory stimuli. Behavioural Brain Research 337, 53-60.

Previous research has shown that rats reared in simple/impoverished environments demonstrate greater repetitive responding for sensory reinforcers (e.g., light onset). Moreover, the brains of these rats are abnormally developed, compared to brains of rats reared...

Faraji, J., Karimi, M., Soltanpour, N. et al. 2018. Intergenerational sex-specific transmission of maternal social experience. Scientific Reports 8, 10529.

The social environment is a major determinant of individual stress response and lifetime health. The present study shows that (1) social enrichment has a significant impact on neuroplasticity and behaviour particularly in females; and (2)...

Burke, C. J., Kisko, T. M., Swiftwolfe, H. et al. 2017. Specific 50-kHz vocalizations are tightly linked to particular types of behavior in juvenile rats anticipating play. PLOS ONE 12(5), e0175841.

Rat ultrasonic vocalizations have been suggested to be either a byproduct of physical movement or, in the case of 50-kHz calls, a means to communicate positive affect. Yet there are up to 14 distinct types...

Jones, T., Robinson, M., Leach, M. et al. 2017. Ultrasonic vocalisation as a measure of positive welfare in rats. Animal Technology and Welfare 16(2), 127-129.

Studies of animal welfare in laboratory animals have historically relied on the measurement of negative indicators rather than the assessment of positive indicators of welfare. Practical methods of welfare assessment are required to allow refinement...

Kruger, M. C., Morel, P. C. H. 2016. Experimental control for the ovariectomized rat model: Use of sham versus nonmanipulated animal. Journal of Applied Animal Welfare Science 19(1), 73-80.

One of 2 models required by the U.S. Food and Drug Administration for registration of a treatment for osteoporosis, the ovariectomized (OVX) rat model, is widely used in scientific studies investigating sex hormone-deficient bone loss...

Winnicker, C., Gaskill, B., Garner, J. P. et al. 2016. A Guide to the Behavior & Enrichment of Laboratory Rodents. Charles River Laboratories.

Covering species-typical behavior as well as abnormal/malfunctional behavior and stereotypes observed in mice, rats, hamsters and gerbils, this is an excellent resource for those looking to implement or enhance an existing behavioral husbandry and enrichment...

Gaskill, B. N., Pritchett-Corning, K. R. 2015. Effect of cage space on behavior and reproduction in CRl:CD(SD) and BN/Crl laboratory rats. JAALAS 54(5), 497-506.

The 2011 Guide for the Care and Use of Laboratory Animals contains recommendations regarding the amount of cage space for mothers with litters. Literature on cage-space use in breeding rats is sparse. We hypothesized that...

Kisko, T. M., Himmler, B. T., Himmler, S. M. et al. 2015. Are 50-kHz calls used as play signals in the playful interactions of rats? II. Evidence from the effects of devocalization. Behavoural Processes 111, 25-33.

During playful interactions, juvenile rats emit many 50-kHz ultrasonic vocalizations, which are associated with a positive affective state. In addition, these calls may also serve a communicative role – as play signals that promote playful...