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. 
Xu, L., Jiao, M., Cui, Z.-L. et al. 2023. Enriched environment during adolescence modulates lipid metabolism and emotion-related behaviors in mice. Journal of Applied Animal Welfare Science 26(2), 218–228.

Enriched environment (EE) is an important animal experimental paradigm to decipher gene-environment interaction. It is thought to be efficient in aiding recovery from certain metabolism disorders or cognitive impairments. Recently, the effects of EE during...

Cho, E., Walsh, C. A., D’Angelo-Gavrish, N. M. et al. 2023. Effects of housing density on reproductive performance, intracage ammonia, and welfare of mice continuously housed as breeders in standard mouse and rat caging. JAALAS 62(2), 116–122.

Maintaining compliance with cage density recommendations in The Guide for the Care and Use of Laboratory Animals precludes continuous trio breeding in standard-sized mouse cages. This study evaluated and compared several parameters of reproductive performance...

Clancy, B. M., Theriault, B. R., Turcios, R. et al. 2023. The effect of noise, vibration, and light disturbances from daily health checks on breeding performance, nest building, and corticosterone in mice. JAALAS 62(4), 291–302.

At our institution, the techniques that technicians use for health checks vary for mice housed in cages on individually ventilated caging (IVC) racks. If the mice cannot be adequately visualized, some technicians partially undock the...

Hickman, D. L. 2023. Euthanasia of neonatal rats and mice using carbon monoxide. JAALAS 62(3), 274–278.

Minimization of potential pain and distress of rodents undergoing euthanasia is a touchstone of veterinary clinical medicine. Evaluation of this issue in postweanling rodents has supported revisions to the AVMA (American Veterinary Medical Association) Guidelines...

LaFollette, M. R., Cloutier, S., Brady, C. M. et al. 2023. Benchmarking enrichment efforts in the US & Canada across species and enrichment categories. JAALAS 62(4), 303–316.

Enrichment is important for animal welfare and data quality. Provision of enrichment opportunities varies between species and enrichment category. However, data benchmarking these differences does not exist. Our objective was to characterize enrichment provision and...

Stuckey, J. E., Makhija, S. D., Reimer, D. C. et al. 2023. Effects of different grades of carbon dioxide on euthanasia of mice (Mus musculus). JAALAS 62(5), 430–437.

Carbon dioxide (CO2) is a conditionally acceptable method for mouse euthanasia, according to the American Veterinary Medical Association Guidelines for the Euthanasia of Animals. In a 2012 Office of Laboratory Animal Welfare (OLAW) webinar, representatives...

Brereton, J., Rose, P. 2022. An evaluation of the role of 'biological evidence' in zoo and aquarium enrichment practices. Animal Welfare 31(1), 13-26.

Evidence-based approaches are key to advancing all areas of zoo and aquarium practice. Output from empirical study must be disseminated to those within the industry so that results can support changes to husbandry and management...

Escobedo-Bonilla, C. M., Quiros-Rojas, N. M., Rudín-Salazar, E. 2022. Rehabilitation of marine turtles and welfare improvement by application of environmental enrichment strategies. Animals 12(3), 282.

Sea turtles perform various ecological services in several marine environments and are considered architects of the marine landscape. At present, they are endangered species due to anthropogenic threats, pollution and degradation of marine habitats. These...

Xu, C., Hou, M., Su, L. et al. 2022. The effect of environmental enrichment on laboratory rare minnows (Gobiocypris rarus): Growth, physiology, and behavior. Animals 12(4), 514.

Environmental enrichment is a method to increase environmental heterogeneity, which may reduce stress and improve animal welfare. Previous studies have shown that environmental enrichment can increase the growth rate, decrease aggressive and anxiety-like behaviors, improve...

Ratuski, A. S., Weary, D. M. 2022. Environmental enrichment for rats and mice housed in laboratories: A metareview. Animals 12(4), 414.

Environmental enrichment has been widely studied in rodents, but there is no consensus on what enrichment should look like or what it should achieve. Inconsistent use of the term “enrichment” creates challenges in drawing conclusions...

Diggins, R., Burrie, R., Ariel, E. et al. 2022. A review of welfare indicators for sea turtles undergoing rehabilitation, with emphasis on environmental enrichment. Animal Welfare 31(2), 219-230.

For animals undergoing rehabilitation it is vital to monitor welfare in a way that is feasible, practical, and limits stress to the animal. The industry gold standard is to assess welfare under the Five Domains...

Kapusta, J., Kruczek, M., Pochroń, E. et al. 2022. Welfare of encaged rodents: Species specific behavioral reaction of voles to new enrichment items. Applied Animal Behaviour Science 246, 105522.

The enrichment of the environment of captive animals is one of the methods applied to reduce stress of the animals and to assure their proper welfare. However, placing objects in a limited space of a...

Gatto, E., Bruzzone, M., Dal Maschio, M. et al. 2022. Effects of environmental enrichment on recognition memory in zebrafish larvae. Applied Animal Behaviour Science 247, 105552.

Zebrafish (Danio rerio) constitute a useful model for studying memory function and impairment in vertebrates and are now widely used in translational research. On the one hand, the adoption of simple, fast and reliable tests...

Perret-Thiry, C., Raulic, J., Vergneau-Grosset, C. 2022. Evaluation of prolonged immersion in tricaine methanesulfonate for juvenile goldfish (Carassius auratus) euthanasia. Journal of the American Veterinary Medical Association 260(8), 911-915.

OBJECTIVE: Doses of buffered tricaine methanesulfonate (MS-222) up to 1000 mg/L for 15 minutes are reported inefficient to produce euthanasia in goldfish. The goal of this study was to determine if goldfish can be euthanized...

Lane, S., Williams, W., Mayo, M. 2022. The impact of environmental enrichment on red-eared slider turtles (Trachemys elegans). Laboratory Animal Science Professional 10(3) (May/June), 18-20.

This study aimed to determine whether tank enrichment improved positive species-specific behaviors (those that benefit the animals' overall well-being), such as basking, and/or decreased negative behaviors (those that may indicate stress, agitation, or discomfort), such...

Hobbiesiefken, U., Mieske, P., Lewejohann, L. et al. 2021. Evaluation of different types of enrichment - their usage and effect on home cage behavior in female mice. PLOS ONE 16(12), e0261876.

Numerous studies ascertained positive effects of enriched environments on the well-being of laboratory animals including behavioral, physiological and neurochemical parameters. Conversely, such conclusions imply impaired animal welfare and health in barren husbandry conditions. Moreover, inappropriate...

Stevens, C., Dobbinson, K., Brook, E. et al. 2022. Report of the 2021 RSPCA/UFAW Rodent Welfare Group meeting. Animal Technology and Welfare 21(2), 83-91.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 28 years, so that its members can discuss current welfare research, exchange views on welfare issues and share experiences of...

Birolo, M., Trocino, A., Zuffellato, A. et al. 2022. Use of gnawing hay blocks: Effects on productive performance, behavior and reactivity of growing rabbits kept in parks with different sex-group compositions. Animals 12(9), 1212.

To improve animal welfare in collective park housing systems, this study assessed the effects of the provision of gnawing hay blocks and the group composition (F: females, M: males, FM: mixed sex) on performance, behavior...

Aldhshan, M. S., Mizuno, T. M. 2022. Effect of environmental enrichment on aggression and the expression of brain-derived neurotrophic factor transcript variants in group-housed male mice. Behavioural Brain Research 433, 113986.

Social and environmental factors influence behavior via modulation of brain physiological functions. Environmental enrichment (EE) is an animal housing technique that provides complex sensory, motor, and social stimulation, leading to modifications in the innate aggressiveness...

Davis, A. K., Garner, J. P., Chu, D. K. et al. 2022. Propofol immersion as a euthanasia method for adult zebrafish (Danio rerio). Comparative Medicine 72(3), 204-209.

The exponential rise of the zebrafish (Danio rerio) as a model organism in biomedical research has far outstripped our un- derstanding of basic husbandry and welfare for this species. As a case in point, here...

Ojelade, O. C., Durosaro, S. O., Akinde, A. O. et al. 2022. Environmental enrichment improves the growth rate, behavioral and physiological response of juveniles of Clarias gariepinus under laboratory conditions. Frontiers in Veterinary Science 9, 980364.

Environmental enrichment (EE) improves the growth rate and welfare of some cultured fishes. However, most cultured fish species are raised in non-enriched housing conditions. Clarias gariepinus is an important commercial fish species, but little is...

Mieske, P., Hobbiesiefken, U., Fischer-Tenhagen, C. et al. 2022. Bored at home?—A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice. Frontiers in Veterinary Science 9, 899219.

Boredom is an emotional state that occurs when an individual has nothing to do, is not interested in the surrounding, and feels dreary and in a monotony. While this condition is usually defined for humans...

Hickman, D. L. 2022. Minimal exposure times for irreversible euthanasia with carbon dioxide in mice and rats. JAALAS 61(3), 283-286.

When using an anesthetic overdose to euthanize laboratory rodents, a secondary method of euthanasia is recommended to ensure that the apparent death is irreversible. This secondary method usually is accomplished through the collection of tissues...

McKinney, M. M., Dupont, W. D., Corson, K. J. et al. 2022. Physiologic and behavioral effects in mice anesthetized with isoflurane in a red-tinted or a traditional translucent chamber. JAALAS 61(4), 322-332.

Isoflurane has been characterized as a distressing agent for rodents, causing both physiologic and behavioral effects. Using a "darkened home cage" has been recommended during CO2 administration for rodent euthanasia; this is arguably a similar...

Marques Maia, C., Volpato, G. L., Braithwaite, V. A. 2022. A psychological aversive condition does not change individual zebrafish preference for background color or artificial plant enrichments. Journal of Applied Animal Welfare Science 25(4), 427-438.

Information on fish preference for environmental conditions can be a useful tool to offer them what they want, an important requirement for welfare purposes. Giving that such an approach deals with psychological states of the...