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. 
Jones, T., Robinson, M., Leach, M. et al. 2017. Ultrasonic vocalisation as a measure of positive welfare in rats. Animal Technology and Welfare 16(2), 127-129.

Studies of animal welfare in laboratory animals have historically relied on the measurement of negative indicators rather than the assessment of positive indicators of welfare. Practical methods of welfare assessment are required to allow refinement...

Pasquarelli, N., Voehringer, P., Henke, J. et al. 2017. Effect of a change in housing conditions on body weight, behavior and brain neurotransmitters in male C57BL/6J mice. Behavioural Brain Research 333, 35-42.

The development of modern housing regimes such as individually ventilated cage (IVC) systems has become very popular and attractive in order to reduce spreading of pathogenic organisms and to lower the risk to develop a...

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...

Tucker, R. D. 2017. Woodchuck College. Laboratory Animal Science Professional 5(2) (June), 33-36.

Marmota monax is a valuable laboratory animal species used in studies of Hepatitis B virus (HBV), food intake, obesity, hibernation, and circannual cycles. This article describes the woodchuck’s (also known as groundhog) natural behavior and...

Makowska, I. J., Weary, D. M. 2016. Differences in anticipatory behaviour between rats (Rattus norvegicus) housed in standard versus semi-naturalistic laboratory environments. PLOS ONE 11(1), e0147595.

Laboratory rats are usually kept in relatively small cages, but research has shown that they prefer larger and more complex environments. The physiological, neurological and health effects of standard laboratory housing are well established, but...

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...

Whittaker, A. L., Lymn, K. A., Howarth, G. S. 2016. Effects of metabolic cage housing on rat behavior and performance in the social interaction test. Journal of Applied Animal Welfare Science 19(4), 363-374.

Although the metabolic cage is commonly used for housing nonhuman animals in the laboratory, it has been recognized as constituting a unique stressor. Such an environment would be expected to affect behavioral change in animals...

Byrd, C. P., Winnicker, C., Gaskill, B. N. 2016. Instituting dark-colored cover to improve central space use within guinea pig enclosure. Journal of Applied Animal Welfare Science 19(4), 408-413.

Domestic guinea pigs (Cavia aperea f. porcellus) in laboratories have been shown to actively avoid the centers of their cages. This experiment tested a novel, dark-colored “shader” placed over the central portion of a cage...

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...

Hawkins, P., Prescott, M., Carbone, L. et al. 2016. A good death? Report of the second Newcastle meeting on laboratory animal euthanasia. Animals 6(9), 50.

Millions of laboratory animals are killed each year worldwide. There is an ethical, and in many countries also a legal, imperative to ensure those deaths cause minimal suffering. However, there is a lack of consensus...

Hickman, D., Fitz, S., Bernabe, C. et al. 2016. Evaluation of low versus high volume per minute displacement CO2 methods of euthanasia in the induction and duration of panic-associated behavior and physiology. Animals 6(8), 45.

Current recommendations for the use of CO 2 as a euthanasia agent for rats require the use of gradual fill protocols (such as 10% to 30% volume displacement per minute) in order to render the...

Allen, K. P., Dwinell, M. R., Zappa, A. M. et al. 2016. Rat breeding parameters according to floor space available in cage. JAALAS 55(1), 21–24.

The cage floor space recommended for a female rat with a litter is greater in the 8th edition of the Guide for the Care and Use of Laboratory Animals than in previous editions. As a...

Makowska, I. J., Weary, D. M. 2016. The importance of burrowing, climbing and standing upright for laboratory rats. Royal Society Open Science 3, 160136.

Standard laboratory cages prevent rats (Rattus norvegicus) from performing many behaviours that they perform in the wild, but little is known about how this may affect their welfare. The aims of this study were (i)...

Zatroch, K. K., Knight, C. G., Reime, J. N. et al. 2017. Refinement of intraperitoneal injection of sodium pentobarbital for euthanasia in laboratory rats (Rattus norvegicus). BMC Veterinary Research 13, 60.

Background: The Canadian Council on Animal Care and American Veterinary Medical Association classify intraperitoneal (IP) pentobarbital as an acceptable euthanasia method in rats. However, national guidelines do not exist for a recommended dose or volume...

Gaskill, B. N., Pritchett-Corning, K. R. 2015. Effect of cage space on behavior and reproduction in CRl:CD(SD) and BN/Crl laboratory rats. JAALAS 54(5), 497-506.

The 2011 Guide for the Care and Use of Laboratory Animals contains recommendations regarding the amount of cage space for mothers with litters. Literature on cage-space use in breeding rats is sparse. We hypothesized that...

Pritchett-Corning, K. R., Gaskill, B. N. 2015. Lack of negative effects on Syrian hamsters and Mongolian gerbils housed in the same secondary enclosure. JAALAS 54(3), 261-266.

In cases where different species might be housed in the same room or secondary enclosure, the Guide for the Care and Use of Laboratory Animals recommends that the animals should be behaviorally compatible and have...

Giral, M., Amengol, C., Sanchez-Gomez, S. et al. 2015. Effects of changing to individually ventilated caging on guinea pigs (Cavia porcellus). JAALAS 54(3), 267-272.

The goal of this study was to evaluate the effect of changing to IVC housing on guinea pigs by recording several physiologic parameters in guinea pigs housed sequentially in open-top cages (OTC) and IVC. To...

Moody, C. M., Makowska, I. J., Weary, D. M. 2015. Testing three measures of mouse insensibility following induction with isoflurane or carbon dioxide gas for a more humane euthanasia. Applied Animal Behaviour Science 163, 183-87.

Laboratory mice are commonly killed via exposure to gradually increasing concentrations of isoflurane and carbon dioxide (CO2) gas. Once rendered insensible using isoflurane or CO2, a high concentration of CO2 is used to decrease time...

Boulanger Bertolus, J., Nemeth, G., Makowska, I. J. et al. 2015. Rat aversion to sevoflurane and isoflurane. Applied Animal Behaviour Science 164, 73-80.

Virtually all rodents used in research are eventually euthanized. Best practice is to anaesthetize these animals before euthanasia using a halogenated anaesthetic such as isoflurane. Exposure to isoflurane is aversive, but less so than exposure...

Wheeler, R. R., Swan, M. P., Hickman, D. L. 2015. Effect of multilevel laboratory rat caging system on the well-being of the singly-housed Sprague Dawley rat. Laboratory Animals 49(1), 10-19.

Current regulations emphasize that good husbandry practices allow animals to engage in species appropriate postural adjustments without touching the enclosure walls. This study evaluated the well-being of rats housed in a commercially available multilevel rat...

Maher, R. L., Barbash, S. M., Lynch, D. V. et al. 2015. Group housing and nest building only slightly ameliorate the cold stress of typical housing in female C57BL/6J mice. American Journal of Physiology 308(12), R1070-R1079.

Huddling and nest building are two methods of behavioral thermoregulation used by mice under cold stress. In the laboratory, mice are typically housed at an ambient temperature (Ta) of 20°C, well below the lower end...

Bayne, K. A., Beaver, B. V., Mench, J. A. et al. 2015. Laboratory animal behavior. In: Laboratory Animal Medicine, 3rd edition. Fox, J. G., Anderson, L., Otto, G., et al. (eds). Elsevier, Inc., Amsterdam, NL. pp. 1617-1651.

The study of laboratory animal behavior has increased steadily over the last decade, with expanding emphasis on a variety of commonly used species. In the United States, this trend was initially focused on species for...

Murphy, S., Fortner, J., Adusumilli, S. 2014. A comparison of soiled bedding densities and stress in sentinel mice. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 609. (Abstract #P225).

Sentinel animals are used to monitor the health status of rodents used in research. It is important to screen for potentially pathogenic viruses, parasites, and bacterial organisms to detect and rapidly respond to unwanted pathogens...

Vilminot, N. M., Patterson, K. A., Cooper, D. M. et al. 2014. Pharmacokinetics and excreta recovery of [14C]Erioglaucine to determine the impact of solid-bottom compared with wire-bottom caging in Sprague-Dawley rats. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 597 (Abstract #P183).

The Guide recommends the use of solid-bottom caging rather than wire-bottom caging in rodents for many reasons, including reduction in environmental stress, allowance for species-typical behaviors, and decreasing the incidence of pododermatitis and other types...

Burman, O., Buccarello, L., Redaelli, V. et al. 2014. The effect of two different individually ventilated cage systems on anxiety-related behaviour and welfare in two strains of laboratory mouse. Physiology & Behavior 124, 92-99.

The environment in which a laboratory animal is housed can significantly influence its behaviour and welfare, acting as a potential confounding factor for those studies in which it is utilised. This study investigated the impact...