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. 
Ballantine, A., Rodgers, D., Watts, C. et al. 2020. The cotton rat – a new challenge. Animal Technology and Welfare 19(1), 92-95.

This poster describes how the Animal Technologists at Envigo adapted their current practices and procedures for a new species at their laboratory: the cotton rat. The paper describes cotton rat biology and behaviour; housing; environmental...

Améndola, L., Weary, D. M. 2020. Understanding rat emotional responses to CO2. Translational Psychiatry 10, 253.

The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO2) exposure. The studies reviewed show that CO2 exposure is aversive to rats, and that rats respond to CO2...

Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss...

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...

Shomer, N. H., Allen-Worthington, K. H., Hickman, D. L. et al. 2020. Review of rodent euthanasia methods. JAALAS 59(3), 242–253.

The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the...

Laferriere, C. A., Pang, D. S. 2020. Review of intraperitoneal injection of sodium pentobarbital as a method of euthanasia in laboratory rodents. JAALAS 59(3), 254–263.

Euthanasia is one of the most commonly performed procedures in biomedical research, involving tens of millions of animals in North America and Europe every year. The use of sodium pentobarbital, injected intraperitoneally, for killing rodents...

Kulkarni, S., Hickman, D. 2020. Isoflurane and carbon dioxide elicit similar behavioral responses in rats. Animals 10(8), 1431.

Euthanasia in rodents is an ongoing topic of debate due to concerns regarding the aversive nature of gases with anesthetic properties such as carbon dioxide (CO2) and isoflurane. The aim of this study was to...

de Castro Travnik, I., de Souza Machado, D., de Silva Gonçalves, L. et al. 2020. Temperament in domestic cats: A review of proximate mechanisms, methods of assessment, its effects on human—cat relationships, and one welfare. Animals 10(9), 1516.

Temperament can be defined as interindividual differences in behavior that are stable over time and in different contexts. The terms ‘personality’, ‘coping styles’, and ‘behavioral syndromes’ have also been used to describe these interindividual differences...

Axiak Flammer, S., Eskes, C., Kohler, I. et al. 2019. Alternatives to carbon dioxide—Taking responsibility for humanely ending the life of animals. Animals 9(8), 482.

Carbon dioxide (CO2) is commonly used to kill rodents. However, a large body of research has now established that CO2 is aversive to them. A multidisciplinary symposium organized by the Swiss Federal Food Safety and...

Steiner, A. R., Axiak Flammer, S., Beausoleil, N. J. et al. 2019. Humanely ending the life of animals: Research priorities to identify alternatives to carbon dioxide. Animals 9(11), 911.

The use of carbon dioxide (CO2) for stunning and killing animals is considered to compromise welfare due to air hunger, anxiety, fear, and pain. Despite decades of research, no alternatives have so far been found...

Madureira, T. V., Costa, J. L., Malhão, F. et al. 2019. Design of a multi-parametric profile for assessing the acclimation period of juvenile brown trout after an acute transport to new housing environment. Applied Animal Behaviour Science 219, 104835.

Fish batches are often transported from aquacultures to laboratory facilities, and this fact triggers a pre-stressed condition that can cause alterations in both physiological and behavioural status of animals. The acclimation before fish trials is...

Association of Primate Veterinarians. 2019. Association of Primate Veterinarians’ guidelines for nonhuman primate restraint. JAALAS 58(3), 282-284.

The Association of Primate Veterinarians (APV) recognizes that several forms of restraint, including physical and chemical, are necessary for the safe handling of nonhuman primates (NHPs). The following guidelines aim to provide information to researchers...

Watz, J. 2019. Structural complexity in the hatchery rearing environment affects activity, resting metabolic rate and post-release behaviour in brown trout Salmo trutta. Journal of Fish Biology 95(2), 638-641.

The effects of structural enrichment in the hatchery rearing environment of brown trout Salmo trutta was linked to post-release performance. Enrichment resulted in reduced swimming activity scored in an open field test and reduced movement...

Animal Welfare Institute. 2019. A new beginning for retired laboratory rabbits. Animal Welfare Institute (AWI) Quarterly 68(4) Winter, 10-11.

This article describes the rehoming of 10 laboratory female rabbits now living as a group in a private shelter.

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...

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...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...

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...

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...

Peric, T., Comin, A., Corazzin, M., et al. 2018. Hair cortisol concentrations in New Zealand white rabbits subjected to surgery. Animal Welfare 27(1), 13-20.

The aim of this study was to assess hair cortisol concentrations in New Zealand white rabbits (Oryctolagus cuniculus) that were subjected to relocation and surgery to evaluate HPA-axis activity; in addition, we used this marker...

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...

Read, H., Perry, R. 2018. A refinement to Schedule 1. Animal Technology and Welfare 17(2), 117-120.

There are varying methods used for animal restraint and angle of injection. It remains unclear whether one method is more accurate than others. The primary objectives were to examine whether inverted restraint of rats resulted...

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...