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. 
Améndola, L., Ratuski, A., Weary, D. M. 2021. Individual differences in rat sensitivity to CO2. PLOS ONE 16(1), e0245347.

Feelings of fear, anxiety, dyspnea and panic when inhaling carbon dioxide (CO2) are variable among humans, in part due to differences in CO2 sensitivity. Rat aversion to CO2 consistently varies between individuals; this variation in...

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...

Conte, F., Voslarova, E., Vecerek, V. et al. 2021. Humane slaughter of edible decapod crustaceans. Animals 11(4), 1089.

Vast numbers of crustaceans are produced by aquaculture and caught in fisheries to meet the increasing demand for seafood and freshwater crustaceans. Simultaneously, the public is increasingly concerned about current methods employed in their handling...

Merkies, K., Franzin, O. 2021. Enhanced understanding of horse–human interactions to optimize welfare. Animals 11(5), 1347.

Horses (Equus caballus) have been domesticated for millennia and are regularly utilized for work, sport, and companionship. Enhanced understanding of human–horse interactions can create avenues to optimize their welfare. This review explores the current research...

Bombail, V., Brown, S. M., Hammond, T. J. et al. 2021. Crying with laughter: Adapting the tickling protocol to address individual differences among rats in their response to playful handling. Frontiers in Veterinary Science 8, 677872.

In this Opinion paper, we consider whether current methods of tickling overemphasize the use of pinning (Figure 1) to which there may be a wider response variation than commonly acknowledged. We do not dispute that...

Kelly, K. J., McDuffee, L. A., Mears, K. 2021. The effect of human–horse interactions on equine behaviour, physiology, and welfare: A scoping review. Animals 11(10), 2782.

Human–horse interactions (HHIs) are diverse and prominent in the equine industry. Stakeholders have an invested interest in making sure that HHIs are humane. Assessment of equine welfare goes beyond physical health and includes assessment of...

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...

Andreasen, S. N., Sandøe, P., Waiblinger, S. et al. 2020. Negative attitudes of Danish dairy farmers to their livestock correlates negatively with animal welfare. Animal Welfare 29(1), 89-98.

Positive stockperson attitudes to his or her animals is associated with a positive behavioural response in the animals and in other indicators assumed to reflect a high level of welfare as well as increased productivity...

Schrimpf, A., Single, M., Nawroth, C. 2020. Social referencing in the domestic horse. Animals 10(1), 164.

Dogs and cats use human emotional information directed to an unfamiliar situation to guide their behavior, known as social referencing. It is not clear whether other domestic species show similar socio-cognitive abilities in interacting with...

Gehlen, H., Loschelder, J., Merle, R. et al. 2020. Evaluation of stress response under a standard euthanasia protocol in horses using analysis of heart rate variability. Animals 10(3), 485.

The effects of a standard protocol for euthanasia on heart rate variability (HRV) as a consequence of stress response were analyzed in this prospective clinical study. The HRV was determined in 40 horses undergoing euthanasia...

Stomp, M., Masson, A., Henry, S. et al. 2020. Could snorts inform us on how horses perceive riding? Behavioural Processes 172, 104041.

Several previous studies have shown that working conditions (including riding) can induce stress in horses. Riders’ actions and postures, when inappropriate, induce stress and conflict behaviours during riding and welfare impairment and negative emotional states...

Costa, R., Leite Tamascia, M., Sanches, A. et al. 2020. Tactile stimulation of adult rats modulates hormonal responses, depression-like behaviors, and memory impairment induced by chronic mild stress: Role of angiotensin II. Behavioural Brain Research 379, 112250.

Physical touch can help to decrease the effects of stress. The aim of this study was to evaluate the influence of tactile stimulation on the hormonal and behavioral responses of young adult rats submitted to...

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...

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...

Okabe, S., Takayanagi, Y., Yoshida, M. et al. 2020. Gentle stroking stimuli induce affiliative responsiveness to humans in male rats. Scientific Reports 10, 9135.

Gentle tactile stimuli have been shown to play an important role in the establishment and maintenance of affiliative social interactions. Oxytocin has also been shown to have similar actions. We investigated the effects of gentle...

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...

Sabiniewicz, A., Tarnowska, K., Świątek, R. et al. 2020. Olfactory-based interspecific recognition of human emotions: Horses (Equus ferus caballus) can recognize fear and happiness body odour from humans (Homo sapiens). Applied Animal Behaviour Science 230, 105072.

Emotional recognition has been demonstrated to occur between members of different species. However, the majority of studies on interspecific communication of emotions so far focused on the senses of vision and hearing while the contribution...

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...

LaFollette, M. R., Cloutier, S., Brady, C. M. et al. 2020. Changing human behavior to improve animal welfare: A longitudinal investigation of training laboratory animal personnel about heterospecific play or “rat tickling”. Animals 10(8), 1435.

Despite evidence for rat tickling’s animal welfare benefits, the technique is rarely implemented in part because of a lack of training. This study’s purpose was to determine the efficacy of online-only or online + hands-on...

Rault, J.-L., Waiblinger, S., Boivin, X. et al. 2020. The power of a positive human–animal relationship for animal welfare. Frontiers in Veterinary Science 7, 590867.

Domestic animals often seek and enjoy interacting with humans. Positive human–animal relationships can elicit positive emotions and other positive welfare outcomes. Nevertheless, our understanding of the underlying processes that govern the positive perception of humans...

Scopa, C., Greco, A., Contalbrigo, L. et al. 2020. Inside the interaction: Contact with familiar humans modulates heart rate variability in horses. Frontiers in Veterinary Science 7, 582759.

A human–animal relationship can be developed through subsequent interactions, affected by the positive or negative emotional valence of the proceeding one. Horses implement a process of categorization to classify humans with whom they interact as...