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. 
Bodden, C., Wewer, M., Kästner, N. et al. 2021. Not all mice are alike: Mixed-strain housing alters social behaviour. Physiology & Behavior 228, 113220.

The use of millions of mice in scientific studies worldwide emphasises the continuing need for a reduction of sample sizes, however, not at the expense of scientific validity. Split-plot designs have been suggested to enhance...

Theil, J. H., Ahloy-Dallaire, J., Weber, E. M. et al. 2020. The epidemiology of fighting in group-housed laboratory mice. Scientific Reports 10(1), 16649.

Injurious home-cage aggression (fighting) in mice affects both animal welfare and scientific validity. It is arguably the most common potentially preventable morbidity in mouse facilities. Existing literature on mouse aggression almost exclusively examines territorial aggression...

Grífols, R., Zamora, C., Ortega-Saez, I. et al. 2020. Postweaning grouping as a strategy to reduce singly housed male mice. Animals 10(11), 2135.

Rearing laboratory mice in groups is important since social isolation after weaning induces brain alterations, which entails behavioral abnormalities in adulthood. Age is an important factor when grouping males of different litters due to inter-male...

Lefebvre, E., Granon, S., Chauveau, F. 2020. Social context increases ultrasonic vocalizations during restraint in adult mice. Animal Cognition 23(2), 351–359.

Adult mice emit many ultrasonic vocalizations (USVs) during social interaction tasks, but only a few studies have yet reported USVs in stressed adult mice. Our aim was to study which experimental conditions favor USV emission...

Nagy-Reis, M. B., Mendonça-Furtado, O., Resende, B. 2019. Do social factors related to allostatic load affect stereotypy susceptibility? Management implications for captive social animals. Animal Welfare 28(2), 183-190.

Stereotypies are frequently associated with sub-optimal captive environments and are used as welfare indicators. However, susceptibility to stereotypy can vary across individuals of the same group. As such, identifying which individuals are more susceptible to...

Melotti, L., Kästner, N., Eick, A. K. et al. 2019. Can live with ‘em, can live without ‘em: Pair housed male C57BL/6J mice show low aggression and increasing sociopositive interactions with age, but can adapt to single housing if separated. Applied Animal Behaviour Science 214, 79-88.

The basic question as to whether male laboratory mice should be singly or group housed represents a major animal welfare concern within current laboratory animal legislation and husbandry. To better understand the behavioural and physiological...

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...

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...

Nip, E., Adcock, A., Nazal, B. et al. 2019. Why are enriched mice nice? Investigating how environmental enrichment reduces agonism in female C57BL/6, DBA/2, and BALB/c mice. Applied Animal Behaviour Science 217, 73-82.

Compared to female mice raised in large, environmentally enriched (EE) cages, those from “shoebox” non-enriched (NE) cages demonstrate more stereotypic behaviour (SB) and depressive-like effects (i.e. learned helplessness; and inactive-but-awake behaviour [IBA], where a mouse...

Brajon, S., Morello, G. M., Teixeira, M. S. et al. 2019. Social environment as a cause of litter loss in laboratory mouse: A behavioural study. Applied Animal Behaviour Science 218, 104827.

Perinatal mortality is a widespread problem in laboratory mouse breeding and is often manifested by the loss of the entire litter within the first days of life. High mortality is an animal health and welfare...

Liang, F., Yang, S., Zhang, Y. et al. 2019. Social housing promotes cognitive function through enhancing synaptic plasticity in APP/PS1 mice. Behavioural Brain Research 368, 111910.

Previous studies have shown that loneliness increases the risk of AD (Alzheimer’s disease) onset, while active and frequent social housing delays the onset of cognitive impairment. The mechanism of how this occurs remains unclear. In...

Dutton III, J. W., Artwohl, J. E., Huang, X. et al. 2019. Assessment of pain associated with the injection of sodium pentobarbital in laboratory mice (Mus musculus). JAALAS 58(3), 373-379.

The AVMA Guidelines for the Euthanasia of Animals considers injection of barbiturates to be an acceptable method of euthanasia in rodents but states there is a potential for pain when administered intraperitoneally. This study examined...

Moffitt, A. D., Brignolo, L. L., Ardeshir, A. et al. 2019. The role of emotional contagion in the distress exhibited by grouped mice exposed to CO2. JAALAS 58(4), 430-437.

The 2013 AVMA Guidelines for the Euthanasia of Animals recommends a chamber volume displacement rate of 10% to 30% per minute (v/min) when euthanizing small laboratory rodents with CO2. Group euthanasia of mice is a...

Hurtado-Parrado, C., Cardona-Zea, Á, Arias-Higuera, M. et al. 2019. Behavioral patterns of laboratory Mongolian gerbils by sex and housing condition: A case study with an emphasis on sleeping patterns. Journal of Veterinary Behavior 30, 69-79.

The behavioral patterns of Mongolian gerbils (Meriones unguiculatus) housed individually and in same-sex groups (siblings) were characterized. Gerbils were continuously video-recorded 24 hours (day 1) and 120 hours (day 5) after housing conditions were established...

Azkona, G., Caballero, J. M. 2019. Implementing strategies to reduce singly housed male mice. Laboratory Animals 53(5), 508–510.

There are different husbandry situations that lead to social isolation of male mice. Besides legal considerations, single housing has a negative impact on behavioural and molecular studies. We have implemented two strategies, the ‘companion mouse’...

Sherrill, C., Kavanagh, K. 2019. Fight Club: Using housing conditions to curb male cage aggression. Laboratory Animal Science Professional 7(1) (March), 38-40.

Those who have worked with C57BL/6 males know how aggressive they can be towards their cage mates. We poured over academic journals, reading every article we could find regarding male home cage aggression. Three articles...

Lidster, K., Owen, K., Browne, W. J. et al. 2019. Cage aggression in group-housed laboratory male mice: An international data crowdsourcing project. Scientific Reports 9, 15211.

Aggression in group-housed laboratory mice is a serious animal welfare concern. Further understanding of the causes of mouse aggression could have a significant impact on a large number of laboratory animals. The NC3Rs led a...

Zidar, J., Weber, E. M., Ewaldsson, B. et al. 2019. Group and single housing of male mice: Collected experiences from research facilities in Sweden. Animals 9(12), 1010.

The mouse is the most commonly used mammal in scientific research, and housed in research facilities around the world. Mice are a social species, but when housing male mice together in a confined environment in...

Gent, T. C., Detotto, C., Vyssotski, A. L. et al. 2018. Epileptiform activity during inert gas euthanasia of mice. PLOS ONE 13(4), e0195872.

Carbon dioxide (CO2) is one of the most commonly used euthanasia agents for mice, yet it is highly aversive and nociceptive. Inert gases are a possible alternative, however there are qualitative reports of seizures resulting...

Dudley, E. S., Boivin, G. P. 2018. Evaluation of a commercially available euthanasia solution as a voluntarily ingested euthanasia agent in laboratory mice. JAALAS 57(1), 30-34.

All currently accepted methods of euthanasia for laboratory mice involve some degree of stress, fear, anxiety, or pain. We evaluated the voluntary oral administration of a euthanasia drug in 99 male and 81 female mice...

Lahger, C., Laska, M. 2018. Behavioral responses of CD-1 mice to conspecific and heterospecific blood odors and to a blood odor component. Physiology & Behavior 184, 2015-210.

The odor of blood may have both aversive and attractive properties for mammals, depending on the species of the odor donor and the species perceiving the odor. To better understand the informational content of blood...

Coke, C., Skoumbourdis, E., Rodgers, J. C. et al. 2018. Blunting/cutting canines of adult male monkeys: A discussion by the Laboratory Animal Refinement & Enrichment Forum. Animal Technology & Welfare 17(2), 105-107.

"When you keep adult Rhesus macaque (Macaca mulatta) males, adult Cynomolgus (Macaca fascicularis) males or adult Vervet males (Chlorocebus pygerythrus), in the same enclosure, is it advisable to have the canines of the males blunted...

Arakawa, H. 2018. Ethological approach to social isolation effects in behavioral studies of laboratory rodents. Behavioural Brain Research 341, 98-108.

The aim of the present review is to discuss how housing conditions affect behavioral performance in laboratory rodents from an ethological view. Commonly used laboratory rodents such as rats and mice, are originally captured animals...

Bailoo, J. D., Murphy, E., Varholick, J. A. et al. 2018. Evaluation of the effects of space allowance on measures of animal welfare in laboratory mice. Scientific Reports 8, 713.

We studied how space allowance affects measures of animal welfare in mice by systematically varying group size and cage type across three levels each in both males and females of two strains of mice (C57BL/6ByJ...

Laszlo, K., Morin, L., Veeder, C. L. 2018. Predictors of pair housing success vary in captive St. Kitts African green monkeys (Chlorocebus sabaeus) versus captive Tanzanian African green monkeys (Chlorocebus pygerythrus). American Journal of Primatology 80(S1), 45 (40th Meeting of the American Society of Primatologists Scientific Program, Abstract #143).

Though African Green Monkeys (AGMs), or vervets, are widely used in research, little is known in regards to their successful pair housing. Due to difficulties with long‐term successful social housing of same‐sex pairs, we attempted...