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. 
Animal Welfare Institute. 2019. Let’s get serious about animal play. AWI Quarterly 68(3) Fall, 19.

This article describes the importance of providing laboratory animals with opportunities to engage in play, and provides a few practical ideas for how to do this.

Leenaars, C. H. C., Pels, E. G. M., Joosten, R. N. J. M. A. et al. 2019. Wistar rats do not show preference for either of two commonly used nutritionally sound food rewards in a T-maze. Journal of Veterinary Behavior 31, 22-27.

Food rewards are commonly used as positive reinforcement in rodent behavioral experiments. Bioserv dustless precision pellets and Noyes formula P precision pellets are both used for this purpose in behavioral experiments in multiple laboratories, as...

Eichner, M., Garcia, K. 2019. Increase in morbidity and mortality in a shipment of red-eared slider turtles (Trachemys scripta elegans). Laboratory Animals 53(6), 634–640.

A cohort of captive-bred red-eared slider turtles, Trachemys scripta, was received from a commercial vendor. Shortly after arrival, several turtles presented as lethargic with subjectively pale skin and multifocal areas of cotton-like tufts in the...

Lynch, C. A., Porter, B., Butler, T. R. 2019. Access to voluntary running wheel exercise: Prevention of anxiety-like behavior in chronically stressed rats, but potentiation of ethanol intake/preference. Physiology & Behavior 206, 118-124.

The current study tested the effect of voluntary running on future anxiety-like behavior, physiological response to stress, and ethanol intake/preference, while including a chronically stressed group and healthy group housed conspecifics. When given concurrently, voluntary...

Améndola, L., Ratuski, A., Weary, D. M. 2019. Variation in the onset of CO2-induced anxiety in female Sprague Dawley rats. Scientific Reports 9, 19007.

Carbon dioxide (CO2) is commonly used to kill laboratory rats. Rats find CO2 aversive and aversion varies between individuals, indicating that rats vary in CO2 sensitivity. Healthy humans experience feelings of anxiety at concentrations similar...

Morano, R., Hoskins, O., Smith, B. L. et al. 2019. Loss of environmental enrichment elicits behavioral and physiological dysregulation in female rats. Frontiers in Behavioral Neuroscience 12, 287.

Chronic stress drives behavioral and physiological changes associated with numerous psychiatric disease states. In rodents, the vast majority of chronic stress models involve imposition of external stressors, whereas in humans stress is often driven by...

Makowska, I. J., Weary, D. M. 2019. A good life for laboratory rodents? ILAR Journal 60(3), 373-388.

Most would agree that animals in research should be spared “unnecessary” harm, pain, or distress, and there is also growing interest in providing animals with some form of environmental enrichment. But is this the standard...

Santurtun, E., Broom, D. M., Phillips, C. J. C. 2018. A review of factors affecting the welfare of Atlantic salmon (Salmo salar). Animal Welfare 27(3), 193-204.

In the expanding salmon industry, many farmers use production methods that could result in poor welfare of the fish at various points of their lifecycle. We have reviewed methods used for producing salmon for food...

Kells, N. J., Beausoleil, N. J., Sutherland, M. A. et al. 2018. Electroencephalographic responses of anaesthetised rats to carbon dioxide inhalation. Animal Welfare 27(3), 215-223.

Exposure to high concentrations of CO2 is a common means of stunning and killing laboratory rodents. However, there is concern regarding the potential for animals to have aversive experiences, such as pain or breathlessness, prior...

Golledge, H., Carter, E. 2018. Welfare of fish farmed in the EU during transport and at slaughter. Animal Welfare 27(3), 287-288.

This Report, commissioned by the European Commission, summarises the current state of transport and slaughter practices in the aquaculture industry within eleven case-study countries in the European Economic Area (EAA). Comparisons are also made with...

Khoo, S. Y.-S., Lay, B. P. P., Joya, J. et al. 2018. Local anaesthetic refinement of pentobarbital euthanasia reduces abdominal writhing without affecting immunohistochemical endpoints in rats. Laboratory Animals 52(2), 152-162.

Sodium pentobarbital is a commonly used agent for euthanizing laboratory rats, however its high pH can cause abdominal discomfort after intraperitoneal injection. Previous studies suggest that the addition of a local anaesthetic may alleviate this...

Clarke, D., Ioannou, L. 2018. Introduction of gang caging for group housed rats. Animal Technology and Welfare 17(2), 136-137.

Using an existing gang cage designed for ferrets, we developed a version that would be suitable for housing rats. Caging consisted of 3 floors with a combined floor area of 11620m, connected by 2 ladders...

Sikora, M., Nicolas, C., Istin, M. et al. 2018. Generalization of effects of environmental enrichment on seeking for different classes of drugs of abuse. Behavioural Brain Research 341, 109-113.

Background: Addiction is a chronic disease characterized by persistent vulnerability to relapse during abstinence. In animal models of addiction, accumulating evidence suggests that exposure to environmental enrichment (EE) during periods of abstinence can have curative...

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...

Hickman D. L. 2018. Interpreting neuroendocrine hormones, corticosterone, and blood glucose to assess the wellbeing of anesthetized rats during euthanasia. JAALAS 57(6), 725–728.

Current recommendations for assessing animal wellbeing during euthanasia suggest that measuring neuroendocrine hormones—such as ACTH, noradrenaline, and adrenaline—is preferable to measuring corticosterone and blood glucose because of the sensitivity of neuroendocrine hormones to the acute...

Hickman D. L. 2018. Home cage compared with induction chamber for euthanasia of laboratory rats. JAALAS 57(6), 729–733.

This study compared behavioral and physiologic changes in Sprague–Dawley and Brown Norway rats that were euthanized by using a 30% volume displacement rate of CO2 in either their home cage or an induction chamber; rats...

Sparling, J. E., Baker, S. L., Bielajew, C. 2018. Effects of combined pre- and post-natal enrichment on anxiety-like, social, and cognitive behaviours in juvenile and adult rat offspring. Behavioural Brain Research 353, 40-50.

The pre- and post-natal periods are characterized by unrivalled growth and are sensitive to environmental changes. A correctly stimulating early environment is essential for developing natural behaviors and maintaining affective wellness. Five litters of rat...

Perdue, B. M., Beran, M. J., Washburn, D. A. 2018. A computerized testing system for primates: Cognition, welfare, and the Rumbaughx. Behavioural Processes 156, 37-50.

Innovations in apparatus technology come about for a variety of reasons such as the need to use the same methodology with various species, the opportunity to present dynamic and carefully controlled stimuli, the goal of...

Hankenson, F. C., Marx, J. O., Gordon, C. J. et al. 2018. Effects of rodent thermoregulation on animal models in the research environment. Comparative Medicine 68(6), 425–438.

To best promote animal wellbeing and the efficacy of biomedical models, scientific, husbandry, and veterinary professionals must consider the mechanisms, influences, and outcomes of rodent thermoregulation in contemporary research environments. Over the last 2 decades...

Heyworth, C., Olivo, D. 2018. Environmental and psychological enrichment for NHPs reimagined and repurposed. Laboratory Animal Science Professional 5(4) (December), 39-43.

This article describes creative enrichment ideas for nonhuman primates, including celery stalks embedded with seeds; paper rolled into tubes, braided and filled with fruit and seeds; pineapple crowns loaded with treats; dry spaghetti noodles coated...

Castelhano-Carlos, M. J., Baumans, V., Sousa, N. 2017. PhenoWorld: Addressing animal welfare in a new paradigm to house and assess rat behaviour. Laboratory Animals 51(1), 36-43.

The use of animals is essential in biomedical research. The laboratory environment where the animals are housed has a major impact on them throughout their lives and influences the outcome of animal experiments. Therefore, there...

Pinelli, C., Leri, F., Turner, P. 2017. Long term physiologic and behavioural effects of housing density and environmental resource provision for adult male and female Sprague Dawley rats. Animals 7(6), 44.

There is considerable interest in refining laboratory rodent environments to promote animal well-being, as well as research reproducibility. Few studies have evaluated the long term impact of enhancing rodent environments with resources and additional cagemates...

Boivin, G. P., Hickman, D. L., Creamer-Hente, M. A. et al. 2017. Review of CO2 as a euthanasia agent for laboratory rats and mice. JAALAS 56(5), 491-499.

Selecting an appropriate, effective euthanasia agent is controversial. Several recent publications provide clarity on the use of CO2 in laboratory rats and mice. This review examines previous studies on CO2 euthanasia and presents the current...

Brenneis, C., Westhof, A., Holschbach, J. et al. 2017. Automated tracking of motion and body weight for objective monitoring of rats in colony housing. JAALAS 56(1), 18-31.

Living together in large social communities within an enriched environment stimulates self-motivated activity in rats. We developed a modular housing system in which a single unit can accommodate as many as 48 rats and contains...

Palmer, S. 2017. Rescue-Enrich-Release: The environmental enrichment program for three species of captive primates at Colobus. Canopy 17(2), 27-30.

It is widely known that the psychological wellbeing of captive animals can become compromised by a captive environment that lacks proper environmental stimulation. Environmental enrichment programs have become the norm in captive environments yet research...