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., 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...

Kendrick, J., Stow, R., Ibbotson, N. et al. 2020. A novel welfare and scientific approach to conducting dog metabolism studies allowing dogs to be pair housed. Laboratory Animals 54(6), 588-598.

Metabolism cages are designed to conduct absorption, distribution, metabolism and excretion (ADME) studies, enabling an ‘excretion balance’ scientific objective to be met. Historically, the design of dog metabolism cages has involved single housing. This type...

Acharya, R., Rault, J.-L. 2020. Risk factors for feather-damaging behavior in companion parrots: A social media study. Journal of Veterinary Behavior 40, 43-49.

Studies on the etiology of behavioral problems often involve interference in the animal's routine or reliance on owners' self-reports like surveys. Gathering data from videos posted on social media, a technique coined ‘video mining’, offers...

Begni, V., Sanson, A., Pfeiffer, N. et al. 2020. Social isolation in rats: Effects on animal welfare and molecular markers for neuroplasticity. PLOS ONE 15(10), e0240439.

Early life stress compromises brain development and can contribute to the development of mental illnesses. A common animal model used to study different facets of psychiatric disorders is social isolation from early life on. In...

Bill, J., Rauterberg, S. L., Herbrandt, S. et al. 2020. Agonistic behavior and social hierarchy in female domestic rabbits kept in semi-groups. Journal of Veterinary Behavior 38, 21-31.

In semi-natural mixed-sex groups, rabbits (Oryctolagus cuniculus) organize their social life by forming a hierarchy, which is characterized by linearity and stability. Compared to the natural environment, many factors are different in contemporary breeding systems...

Cloutier Barbour, C., Danforth, M. D., Murphy, H. et al. 2020. Monitoring great ape heart health through innovative electrocardiogram technology: Training methodologies and welfare implications. Zoo Biology 39(6), 443-447.

Assessing and treating cardiovascular disease (or heart disease) is a growing concern for institutions housing great apes, as it is a major cause of mortality in all four taxa managed in human care. As part...

Natusch, D. J. D., Aust, P. W., Khadiejah, S. et al. 2020. Behavioral and corticosterone responses to carbon dioxide exposure in reptiles. PLOS ONE 15(10), e0240176.

The use of carbon dioxide (CO2) exposure as a means of animal euthanasia has received considerable attention in mammals and birds but remains virtually untested in reptiles. We measured the behavioral responses of four squamate...

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...

McFarland, R., Barrett, L., Fuller, A. et al. 2020. Infrared thermography cannot be used to approximate core body temperature in wild primates. American Journal of Primatology 82, e23204.

Understanding the physiological processes that underpin primate performance is key if we are to assess how a primate might respond when navigating new and changing environments. Given the connection between a mammal's ability to thermoregulate...

Yngvesson, J., Rey Torres, J. C., Lindholm, J. et al. 2019. Health and body conditions of riding school horses housed in groups or kept in conventional tie-stall/box housing. Animals 9(3), 73.

We compared welfare measures of horses among Swedish riding schools (RS) during winter where horses were kept either in group housing (n = 8) or in tie-stalls/boxes (n = 8), Health data for six previous...

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...

Dal Bosco, A., Mugnai, C., Martino, M. et al. 2019. Housing rabbit does in a combi system with removable walls: Effect on behaviour and reproductive performance. Animals 9(8), 528.

We evaluated the effects of two types of colony cages, in which rabbit does were always in a group (C1), and where they were in combi cages furnished with removable internal walls to allow both...

Trocino, A., Zomeño, C., Filiou, E. et al. 2019. The use of environmental enrichments affects performance and behavior of growing rabbits housed in collective pens. Animals 9(8), 537.

This study assessed the effects of an elevated plastic-slatted platform and/or a plastic hiding tube in collective pens with large group sizes (27 or 36 rabbits/pen; 16 rabbits/m2) on the performance and welfare of rabbits...

Euet, A., Lemarchand, J., Parias, C., Mach, N. et al. 2019. Housing horses in individual boxes is a challenge with regard to welfare. Animals 9(9), 621.

Horses are mainly housed in individual boxes. This housing system is reported to be highly detrimental with regard to welfare and could trigger the expression of four behavioural indicators of a compromised welfare state: stereotypies...

Gerencsér, Z., Matics, Z., Szabó, R. et al. 2019. Aggressiveness, mating behaviour and lifespan of group housed rabbit does. Animals 9(10), 708.

Aggressiveness is one of the main problems in group housing of rabbit does. The aim of the experiment was to investigate the frequency of aggressiveness and mating behaviour as well as the lifespan of does...

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...

Contreras-Aguilar, M. D., Henry, S., Coste, C. et al. 2019. Changes in saliva analytes correlate with horses' behavioural reactions to an acute stressor: A pilot study. Animals 9(11), 993.

Acute stress induces an array of behavioural reactions in horses that vary between individuals. Attempts to relate behavioural patterns and physiological responses have not always given clear-cut results. Here, we measured the changes in a...

Costa, J. H. C., Cantor, M. C., Adderley, N. A. et al. 2019. Key animal welfare issues in commercially raised dairy calves: social environment, nutrition, and painful procedures. Canadian Journal of Animal Science 99(4), 649-660.

Dairy calf welfare concerns are growing and new evidence suggests that the early life environment influences appropriate physical, behavioral, and cognitive development lasting into adulthood. This review highlights key evidence for the impacts of housing...

Bartley, K. A., Johnson, C. H. 2019. Human infant pants for postoperative protection during social housing of New Zealand white rabbits (Oryctolagus cuniculus). JAALAS 58(4), 510-516.

Elizabethan collars (E-collars) are commonly used in various species to safeguard healing wounds. However, E-collars inadvertently restrict the expression of normal species-typical behaviors, including coprophagy, self-grooming, and social housing. To maintain social housing in accordance...

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.

Pierard, M., McGreevy, P., Geers, R. 2019. Effect of density and relative aggressiveness on agonistic and affiliative interactions in a newly formed group of horses. Journal of Veterinary Behavior 29, 61-69.

Group housing provides horses with social contact, a lack of which is associated with health and behavior problems. Despite the benefits of group housing for horses, horse owners are concerned about aggression and resulting injuries...