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. 
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...

Kruger, M. C., Morel, P. C. H. 2016. Experimental control for the ovariectomized rat model: Use of sham versus nonmanipulated animal. Journal of Applied Animal Welfare Science 19(1), 73-80.

One of 2 models required by the U.S. Food and Drug Administration for registration of a treatment for osteoporosis, the ovariectomized (OVX) rat model, is widely used in scientific studies investigating sex hormone-deficient bone loss...

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...

Mattheis, L., Jung, J.-S., Hiebl, B. et al. 2016. Perioperative support reduces mortality of obese BALB/c mice after ovariectomy. Lab Animal 45(7), 262-267.

The incidence of obesity is on the rise in most western countries and represents major risks to health. Obesity causes complex metabolic dysfunctions and can be associated with a large number of secondary diseases. To...

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...

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...

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...

Jackson, E., Demarest, K., Eckert, W. J. et al. 2015. Aspen shaving versus chip bedding: Effects on breeding and behavior. Laboratory Animals 49(1), 46-56.

The choice of laboratory cage bedding material is often based on both practical and husbandry issues, whereas behavioral outcomes rarely appear to be considered. It has been noted that a breeding success difference appears to...

Lima, F. B., de Oliveira, E. S. 2014. What is the impact of low testosterone levels on the anatomical and behavioral repertoire of long-term enriched housing of male mice? Behavioral Processes 108, 57-64.

Environmental enrichment is a strategy to improve animal welfare, providing brain plasticity with changes at cellular, molecular and behavioral levels. In order to test the long-term effects of enriched housing and the importance of testosterone...

Braden, G.C., Rasmussen, S., Tolwani, R.J. 2014. Effects of breeding configuration on behavior, reproduction, and pathology in the laboratory mouse (Mus musculus). American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 605. (Abstract #P210).

While numerous published studies have evaluated the effect of housing density on the wellbeing of laboratory mice, little is known on the effect of breeding configuration. The eighth edition of the Guide for the Care...

van Leeuwen, E. J. C., Mulenga, I. C., Chidester, D. L. 2014. Early social deprivation negatively affects social skill acquisition in chimpanzees (Pan troglodytes). Animal Cognition 17(2), 407–414.

In a highly social species like chimpanzees, the process by which individuals become attuned to their social environment may be of vital importance to their chances of survival. Typically, this socialization process, defined by all...

Lambeth, S. P., Schapiro, S. J., Bernacky, B. J. et al. 2013. Establishing 'quality of life' parameters using behavioural guidelines for humane euthanasia of captive non-human primates. Animal Welfare 22(4) 429-435.

Chronic pain and distress are universally accepted conditions that may adversely affect an animal’s quality of life (QOL) and lead to the humane euthanasia of an animal. At most research institutions and zoological parks in...

Wong, D., Makowska, I. J., Weary, D. M. 2013. Rat aversion to isoflurane versus carbon dioxide. Biology Letters 9(1), 20121000.

Some experts suggest that sedation of laboratory rodents with isoflurane before euthanasia with carbon dioxide (CO2) is a humane alternative to euthanasia with CO2 alone, but little research has compared aversion with these agents. Albino...

Chisholm, J., De Rantere D., Fernandez, N. J. et al. 2013. Carbon dioxide, but not isoflurane, elicits ultrasonic vocalizations in female rats. Laboratory Animals 47(4), 324-7.

Gradual filling of a chamber with carbon dioxide is currently listed by the Canadian Council on Animal Care guidelines as a conditionally acceptable method of euthanasia for rats. Behavioural evidence suggests, however, that exposure to...

Shair, H. N., Nunez, Y., Osman, M. M. 2012. Enrichment materials do not negatively affect reproductive success and offspring survival and weight in mice. Lab Animal 41(1), 14-19.

Environmental enrichment is designed to improve the overall welfare of laboratory animals, including mice. Few studies have directly assessed the effects of different types of enrichment on mouse offspring survival and growth. The authors examined...

Merriman, D. K., Lahvis, G., Jooss, M. et al. 2012. Current practices in a captive breeding colony of 13-lined ground squirrels (Ictidomys tridecemlineatus). Lab Animal 41(11), 315-325.

The authors provide an update to their 2006 report on the successful large-scale captive breeding of the 13-lined ground squirrel (TLGS; Ictidomys tridecemlineatus) in their colony, now a single-source supplier of purpose-bred TLGSs for several...

Coleman, K. 2012. Individual differences in temperament and behavioral management practices for nonhuman primates. Applied Animal Behaviour Science 137(3-4), 106-113.

This review will examine how individual differences in temperament might affect, or be affected by, behavioral management practices for captive primates. Measuring temperament may help us predict the outcome of social introductions. It can also...

Paula, A. A., Goyeneche, L., Crispo, M. 2011. Refining housing and husbandry techniques in transgenic mice through environmental enrichment. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 777 (Abstract #P148).

Dynamic changes in housing and husbandry techniques based on the concept of 3Rs should be included as routine practice in breeding and experimental animal facilities tending to improve animal welfare. Immunosupressed mice are susceptible to...

Neves, S. 2011. Effects of environmental enrichment on the production of C57BL/6 mice kept in different housing systems. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 788 (Abstract #P201).

The goal of this study was to evaluate the effects of environmental enrichment on the performance of C57BL/6 mice kept in conventional animal facilities (open cage; OC) and individually ventilated caging system (IVC). We analyzed...

Griess, R. S. 2011. Environmental enrichment improves fertility and pup survival. Tech Talk [The Newsletter for Laboratory Animal Science Technicians] 16(1), 2-3.

Historically, we have added approximately half a cup of shredded aspen bedding for nest making into each littering cage. This procedure was continued as we looked into additional environmental enrichment. There are many types of...

Gaskill, B., Winnicker, C. L., Garner, J. P. et al. 2011. The naked truth: Breeding performance in outbred and inbred strains of nude mice with and without nesting material. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 741 (Abstract #PS95).

In laboratories, mice are housed at ambient temperatures between 20 to 24 °C, which is below their lower critical temperature of 30 °C, but comfortable for human workers. Thus, mice are thermally stressed, which can...

Gaskill, B., Garner, J. P., Pritchett-Corning, K. 2011. Energy reallocation to breeding performance through improved behavioral thermoregulation. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 771 (Abstract #P120).

Mice are housed at temperatures which increase their basal metabolic rates and impose high energy demands to maintain core temperatures. Thus, energy may be reallocated from other biologic processes to increase heat production. We hypothesized...