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. 
Brunt, M. W., Améndola, L., Weary, D. M. 2021. Attitudes of laboratory animal professionals and researchers towards carbon dioxide euthanasia for rodents and perceived barriers to change. Laboratory Animals 55(6), 531-539.

Evidence indicates that carbon dioxide (CO2) induces negative affective states (including anxiety, fear and distress) in laboratory rodents, but many countries still accept it for euthanasia. Alternative methods (e.g. inhalant anaesthetic) may represent a refinement...

Winn, C. B., Hwang, S. K., Morin, J. et al. 2021. Automated monitoring of respiratory rate as a novel humane endpoint: A refinement in mouse metastatic lung cancer models. PLOS ONE 16(9), e0257694.

In oncology research, while xenograft tumor models are easily visualized and humane endpoints can be clearly defined, metastatic tumor models are often based on more subjective clinical observations as endpoints. This study aimed at identifying...

Miller, A. L., Roughan, J. V. 2021. Welfare assessment, end-point refinement and the effects of non-aversive handling in C57BL/6 mice with Lewis lung cancer. Animals 12(1), 23.

Cancer-bearing mice are at risk of developing anxiety, pain, or malaise. These conditions may not only harm welfare but could also undermine data quality and translational validity in studies to develop therapeutic interventions. We aimed...

Verjat, A., Devienne, P., Rödel, H. G. et al. 2021. More exploratory house mice judge an ambiguous situation more negatively. Animal Cognition 24(1), 53–64.

Exploration tendency, one of the most investigated animal personality traits, may be driven by either positive (when seeking interesting information) or negative (to reduce the uncertainty of the environment) affective/emotional profiles. To disentangle the valence...

Talbot, S. R., Biernot, S., Bleich, A. et al. 2020. Defining body-weight reduction as a humane endpoint: A critical appraisal. Laboratory Animals 54(1), 99–110.

In many animal experiments scientists and local authorities define a body-weight reduction of 20% or more as severe suffering and thereby as a potential parameter for humane endpoint decisions. In this study, we evaluated distinct...

Składanowska-Baryza, J., Ludwiczak, A., Pruszyńska-Oszmałek, E. et al. 2020. Effect of two different stunning methods on the quality traits of rabbit meat. Animals 10(4), 700.

The aim of the study was to assess the effect of two different stunning methods on the level of blood stress indicators (cortisol, insulin, glucose) and rabbit meat quality. The experiment was conducted on crossbreds...

Frost, K., Shah, M., Leung , V. S. Y. et al. 2020. Aversion to desflurane and isoflurane in Sprague-Dawley rats (Rattus norvegicus). Animals 10(6), 950.

Carbon dioxide and isoflurane are widely used for killing rats, yet may not truly achieve “euthanasia”, because they elicit aversion. The inhalant anesthetic desflurane is faster acting than isoflurane, representing a potential refinement. Using an...

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...

Nwagwu, C. D., Defensor, E., Jiang, M. Y. et al. 2020. Endpoint in ovarian cancer xenograft model predicted by nighttime motion metrics. Lab Animal 49(8), 227–232.

Despite several therapeutics showing promise in nonclinical studies, survival from ovarian cancer remains poor. New technologies are urgently needed to optimize the translation of nonclinical studies into clinical successes. While most nonclinical settings utilize subjective...

Wilkinson, M. J. A., Selman, C., McLaughlin, L. et al. 2020. Progressing the care, husbandry and management of ageing mice used in scientific studies. Laboratory Animals 54(3) 225–238.

Driven by the longer lifespans of humans, particularly in Westernised societies, and the need to know more about ‘healthy ageing’, ageing mice are being used increasingly in scientific research. Many departments and institutes involved with...

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...

Helgers, S., Talbot, S. R., Riedesel, A. K. et al. 2020. Body weight algorithm predicts humane endpoint in an intracranial rat glioma model. Scientific Reports 10, 9020.

Humane endpoint determination is fundamental in animal experimentation. Despite commonly accepted endpoint criteria for intracranial tumour models (20% body weight loss and deteriorated clinical score) some animals still die before being euthanized in current research...

Zhang, X., Kumstel, S., Tang, G. et al. 2020. A rational approach of early humane endpoint determination in a murine model for cholestasis. ALTEX 37(2), 197-207.

Reduction of animal suffering during in vivo experiments is usually ensured by continuously monitoring the health status using a score sheet and by applying humane endpoints. However, most studies do not evaluate the plausibility of...

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...

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...

Laferriere, C. A., Leung, V. S., Pang, D. S. 2020. Evaluating intrahepatic and intraperitoneal sodium pentobarbital or ethanol for mouse euthanasia. JAALAS 59(3), 264–268.

Intraperitoneal (IP) injection of sodium pentobarbital (PB) is an accepted method of euthanasia for mice. However, this method has important drawbacks, including the potential for pain or misinjection. The objective of this prospective, randomized, blinded...

Cohen, S., Kwok, M., Huang, J. 2020. Humane euthanasia of guinea pigs (Cavia porcellus) with a penetrating spring-loaded captive bolt. Animals 10(8), 1356.

Guinea pigs (Cavia porcellus) have been used in research since the 19th century to collect data due to their physiological similarities to humans. Today, animals perform a vital role in experiments and concerns for laboratory...

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...

Do, J. P., Defensor, E. B., Ichim, C. V. et al. 2020. Automated and continuous monitoring of animal welfare through digital alerting. Comparative Medicine 70(4), 313-327.

A primary goal in preclinical animal research is respectful and responsible care aimed toward minimizing stress and discomfort while enhancing collection of accurate and reproducible scientific data. Researchers use hands-on clinical observations and measurements as...

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...

Williams, E., Carter, A., Hall, C. et al. 2019. Exploring the relationship between personality and social interactions in zoo-housed elephants: Incorporation of keeper expertise. Applied Animal Behaviour Science 221, 104876.

Individual animal personalities affect experiences of zoo environments, and thus potentially welfare. Incorporating keeper knowledge of animal personality in a reliable way has great value in optimising welfare in zoo-housed animals. Assessment of animal personality...

Stevens, C., Hawkins, P., Lovell-Badge, R. et al. 2019. Report of the 2018 RSPCA/UFAW Rodent and Rabbit Welfare Group meeting. Animal Technology and Welfare 18(2), 81-91.

The RSPCA/UFAW Rodent (and now Rabbit) Working Group has held a one-day meeting every autumn for the last 25 years, so that its members can discuss current welfare research, exchange views on welfare issues and...

Cowley, P. M., Roberts, C. R., Baker, A. J. 2019. Monitoring the health status of mice with bleomycin-induced lung injury by using body condition scoring. Comparative Medicine 69(2), 95–102.

Well-defined, humane endpoints aid in monitoring animal health status during disease development. Body condition scoring (BCS) is a method for assessing health status in mouse studies where wasting and death are potential endpoints. Whether BCS...