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. 
Hohlbaum, K., Bert, B., Dietze, S. et al. 2017. Severity classification of repeated isoflurane anesthesia in C57BL/6JRj mice—Assessing the degree of distress. PLOS ONE 12(6), e0179588.

According to the EU Directive 2010/63, the severity of a procedure has to be classified as mild, moderate or severe. General anesthesia is thought to be mild, but the Directive does not differentiate between single...

Freymann, J., Tsai, P.-P., Stelzer, H. D. et al. 2017. Impact of bedding volume on physiological and behavioural parameters in laboratory mice. Laboratory Animals 51(6), 601-612.

The standard housing temperature in animal facilities is substantially below the lower critical temperature of mice. This does not only endanger animal welfare, it can also jeopardize scientific research as cold stress has a major...

Robinson-Junker, A., Morin, A., Pritchett-Corning, K. et al. 2017. Sorting it out: Bedding particle size and nesting material processing method affect nest complexity. Laboratory Animals 51(2), 170-180.

As part of routine husbandry, an increasing number of laboratory mice receive nesting material in addition to standard bedding material in their cages. Nesting material improves health outcomes and physiological performance in mice that receive...

Mogil, J. S. 2017. Laboratory environmental factors and pain behavior: The relevance of unknown unknowns to reproducibility and translation. Lab Animal 46(4), 136-141.

The poor record of basic-to-clinical translation in recent decades has led to speculation that preclinical research is “irreproducible”, and this irreproducibility in turn has largely been attributed to deficiencies in reporting and statistical practices. There...

Gaskill, B. N., Stottler, A. M., Garner, J. P. et al. 2017. The effect of early life experience, environment, and genetic factors on spontaneous home-cage aggression-related wounding in male C57BL/6 mice. Lab Animal 46(4), 176-184.

Aggression is a major welfare issue in mice, particularly when mice unfamiliar to each other are first placed in cages, as happens on receipt from a vendor, and following cage cleaning. Injuries from aggression are...

Gerwin, P. M., Ricart Arbona, R. J., Riedel, E. R. et al. 2017. PCR testing of IVC filter tops as a method for detecting murine pinworms and fur mites. JAALAS 56(6), 752-761.

We evaluated PCR testing of filter tops from cages maintained on an IVC system through which exhaust air is filtered at the cage level as a method for detecting parasite-infected and -infested cages. Cages containing...

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...

Skorupski, A. M., Zhang, J., Ferguson, D. et al. 2017. Quantification of induced hypothermia from aseptic scrub applications during rodent surgery preparation. JAALAS 56(5), 562-569.

Laboratory mice (Mus musculus) are prone to develop hypothermia during anesthesia for surgery, thus potentially impeding anesthetic recovery, wound healing, and future health. The core body temperatures of isoflurane-anesthetized mice are influenced by the choice...

de Souza Dyer, C., Brice, A. K., Marx, J. O. 2017. Intraperitoneal administration of ethanol as a means of euthanasia for neonatal mice (Mus musculus). JAALAS 56(3), 299-306.

The humane euthanasia of animals in research is of paramount importance. Neonatal mice frequently respond differently to euthanasia agents when compared with adults. The AVMA's Guidelines for the Euthanasia of Animals includes intraperitoneal injection of...

Reiter, C. P., Christy, A. C., Olsen, C. H. et al. 2017. Effect of home cage bedding in the induction chamber on serum cortisol and corticosterone levels in response to isoflurane-induced anesthesia in C57BL/6J mice. JAALAS 56(2), 118-121.

Mice are routinely anesthetized with isoflurane in an induction chamber. The AVMA Guidelines for the Euthanasia of Animals states that distress should be minimized during euthanasia but does not address this point in regard to...

Janssen, C. F., Maiello, P., Wright Jr, M. J. et al. 2017. Comparison of atipamezole with yohimbine for antagonism of xylazine in mice anesthetized with ketamine and xylazine. JAALAS 56(2), 142-147.

The α2 adrenergic agonist xylazine produces a sedative effect and is typically combined with ketamine and used for anesthesia or chemical restraint of laboratory mice. Xylazine's sedative effect—and its undesirable side effects of bradycardia, hypotension...

Wilding, L. A., Hampel, J. A., Khoury, B. M. et al. 2017. Benefits of 21% oxygen compared with 100% oxygen for delivery of isoflurane to mice (Mus musculus) and rats (Rattus norvegicus). JAALAS 56(2), 148-154.

At research institutions, isoflurane delivered by precision vaporizer to a face mask is the standard for rodent surgery and for procedures with durations that exceed a few minutes. Pure oxygen is often used as the...

Gordon, C. J., Puckett, E. T., Repasky, E. S. et al. 2017. A device that allows rodents to behaviorally thermoregulate when housed in vivariums. JAALAS 56(2), 173-176.

Laboratories and vivariums typically are maintained at ambient temperatures of 20 to 24 °C, leading to cold stress in mice. When mice are inactive and sleeping during the light phase, their zone of thermoneutrality associated...

Boivin, G. P., Bottomley, M. A., Schiml, P. A. et al. 2017. Physiologic, behavioral, and histologic responses to various euthanasia methods in C57BL/6NTac male mice. JAALAS 56(1), 69-78.

Rodent euthanasia using exposure to increasing concentrations of CO2 has come under scrutiny due to concerns of potential pain during the euthanasia process. Alternatives to CO2, such as isoflurane and barbiturates, have been proposed as...

Hawkins, P., McNeilly, A., Watson, J. et al. 2017. Report of the 2016 RSPCA/UFAW Rodent and Rabbit Welfare Group meeting. Animal Technology and Welfare 16(2), 77-86.

The RSPCA/UFAW Rodent (and now Rabbit) Welfare Group held a one-day meeting on 1 November 2016 at the University of Edinburgh and was attended by 70 delegates. Presentation topics included refinements in blood sampling rodents...

Mancera, K. F., Lisle, A. Allavena, R. et al. 2017. The effects of mining machinery noise of different frequencies on the behaviour, faecal corticosterone and tissue morphology of wild mice (Mus musculus). Applied Animal Behaviour Science 197, 81-89.

Mining noise has a wide variety of frequency spectra and is a potential source of stress for wildlife. We evaluated the effects of mining machinery noise on behaviour and associated physiological parameters at two isoenergetic...

Guedes, S. R., Valentim, A. M., Antunes, L. M. 2017. Mice aversion to sevoflurane, isoflurane and carbon dioxide using an approach-avoidance task. Applied Animal Behaviour Science 189, 91-97.

Euthanasia of laboratory animals is one of the main concerns for animal welfare, especially the use of carbon dioxide (CO2) which has been described to induce aversive-like behaviours. In order to refine mass euthanasia in...

Freymann, J., Tsai, P.-P., Stelzer, H. et al. 2017. The impact of bedding volumes on laboratory mice. Applied Animal Behaviour Science 186, 72-79.

Environmental refinement is considered to be an improvement in housing conditions for laboratory animals. Previous preference tests showed that female BALB/c and C57BL/6 mice prefer deeper bedding in comparison to shallow bedding (Freymann et al...

Yin, L., Yang, H., Xu, L. et al. 2017. Feather performance, walking ability, and behavioral changes of geese in response to different stocking densities. Applied Animal Behaviour Science 196, 108-112.

In recent decades, goose production has become more specialized and widespread, and rearing geese in plastic wire-floor pens is common in China. This type of rearing pattern is more productive than other rearing patterns since...

Alves-Simoes, M., Coleman, G., Canal, M. M. 2016. Effects of type of light on mouse circadian behaviour and stress levels. Laboratory Animals 50(1), 21-29.

Light is the principal synchronizing environmental factor for the biological clock. Light quantity (intensity), and light quality (type of light source) can have different effects. The aim of this study was to determine the effects...

Norton, W. B., Scavizzi, F., Smith, C. D. et al. 2016. Refinements for embryo implantation surgery in the mouse: Comparison of injectable and inhalant anesthesias – tribromoethanol, ketamine and isoflurane – on pregnancy and pup survival. Laboratory Animals 50(5), 335-343.

An essential aspect of genetically-engineered mice (GEM) is the ability to produce live animals after the appropriate injection procedure. Animals are produced by implantation of manipulated embryos into pseudopregnant females for gestation, parturition, and growth...

López-Salesansky, N., Mazlan, N. H., Whitfield, L. E. et al. 2016. Olfaction variation in mouse husbandry and its implications for refinement and standardization: UK survey of animal scents. Laboratory Animals 50(5), 362-369.

Olfaction plays a crucial role in mouse communication, providing information about genetic identity, physiological status of conspecifics and alerting mice to potential predators. Scents of animal origin can trigger physiological and behavioural responses that could...

Valentim, A. M., Guedes, S. R., Pereira, A. M. et al. 2016. Euthanasia using gaseous agents in laboratory rodents. Laboratory Animals 50(4), 241-253.

Several questions have been raised in recent years about the euthanasia of laboratory rodents. Euthanasia using inhaled agents is considered to be a suitable aesthetic method for use with a large number of animals simultaneously...

López-Salesansky, N., Mazlan, N. H., Whitfield, L. E. et al. 2016. Olfactory variation in mouse husbandry and its implications for refinement and standardization: UK survey of non-animal scents. Laboratory Animals 50(4), 286-295.

With their highly sensitive olfactory system, the behaviour and physiology of mice are not only influenced by the scents of conspecifics and other species, but also by many other chemicals in the environment. The constraints...

Powell, K., Ethun, K., Taylor, D. K. 2016. The effect of light level, CO2 flow rate, and anesthesia on the stress response of mice during CO2 euthanasia. Lab Animal 45(10), 386-395.

Euthanasia protocols are designed to mitigate the stress experienced by animals, and an environment that induces minimal stress helps achieve that goal. A protocol that is efficient and practical in a typical animal research facility...