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. 
Lavery, J. M., Mason, G. J. 2023. Mirror, mirror on the wall… How tank material and the presence of “enrichments” affect competition and agonism in zebrafish (Danio rerio). Applied Animal Behaviour Science 266, 106005.

Despite generations of rearing in a laboratory environment, zebrafish (Danio rerio) retain innate preferences for environmental features that mimic their natural habitat (e.g. plants and gravel), but the effects of such preferred housing conditions on...

Miguelena Chamorro, B., Swaminathan, G., Mundt, E. et al. 2023. Towards more translatable research: Exploring alternatives to gavage as the oral administration route of vaccines in rodents for improved animal welfare and human relevance. Lab Animal 52(9), 195–197.

Oral vaccines are gaining attention for their ease of administration and ability to activate mucosal immune responses. However, preclinical studies using this route often require the use of gavage, which has limitations. In this comment...

Munro, B. A., Merenick, D. R., Gee, J. M. et al. 2023. Use of loss of righting reflex to assess susceptibility to carbon dioxide gas in three mouse strains. JAALAS 62(6), 553–558.

Exposure to CO2 gas is a common rodent euthanasia method. CO2 activates nociceptors in rats and is painful to humans at concentrations equal to or greater than 32.5% The concentration of CO2 at which rodents...

Neville, V., Hunter, K., Benato, L. et al. 2023. Developing guidelines for pet rat housing through expert consultation. Veterinary Record 192(3), e1839.

Background Pet care guidelines play an important role in ensuring that owners are well informed about good husbandry practices, allowing them to provide the best care for their animals. However, the development of such guidelines...

Neville, V., Lind, J., Mendl, E. et al. 2023. A mapping review of refinements to laboratory rat housing and husbandry. Lab Animal 52(3), 63–74.

Refining the housing and husbandry of laboratory rats is an important goal, both for ethical reasons and to allow better quality research. We conducted a mapping review of 1,017 studies investigating potential refinements of housing...

Spain, M., Pearson, C., Rosenblatt, A. E. 2023. Social structure and habitat design affect the impact of a novel feeding enrichment for alligators. Zoo Biology 42(3), 383–389.

Providing enrichment that expands the range of behavioral opportunities associated with food acquisition and environmental exploration is an important contributing factor to the well-being of zoo animals. These behaviors can be difficult to promote in...

Truax, J., Vonk, J. 2023. Silence is golden: Auditory preferences in zoo-housed gorillas. Journal of Applied Animal Welfare Science 26(3), 404–419.

Enrichment is presented to improve the welfare of captive animals but sound is frequently presented with the assumption that it is enriching without assessing individuals’ preferences. Typically, presented sounds are unnatural and animals are unable...

Tsuchiya, Y., Yayota, M., Kashima, Y. et al. 2023. Nutritional effect of feeding enrichment using bamboo Pleioblastus spp. in zoo-kept Asian elephants Elephas maximus. Journal of Zoo and Aquarium Research 11(2), 267–273.

Many zoos use browse and other roughage as feed ingredients and enrichment tools for elephants. Amongst these are bamboo species (e.g. Pleioblastus spp.), which belong to the family of grasses. Bamboo is used in zoos...

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...

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...

McNamara, A., Ballantine, A. R., Deuchande, R. et al. 2023. Comparison of fixed and rising displacement rates of CO2 for euthanasia of aged rats. JAALAS 62(5), 453–463.

This study compared euthanasia induced by rising concentrations of CO2 in aged rats (n = 59) using different gas displacement rates. Rats were preimplanted with cardiovascular telemetry devices and had been previously used for short...

Olagbaju, T. T., Troan, B. V., Balko, J. A. 2023. Investigation of potassium chloride for euthanasia of anesthetized African clawed frogs (Xenopus laevis). JAALAS 62(4), 362–369.

Euthanasia is frequently performed in amphibians, but techniques are currently limited in number and variable in effectiveness. The current study examined the use of potassium chloride (KCl) for euthanasia of anesthetized African clawed frogs (Xenopus...

Riddell, D. L., Hyndman, T. H., Bowden, R. S. et al. 2023. Use of a low-calorie flavored gel to facilitate oral self-administration of analgesics in mice. JAALAS 62(2), 163–169.

The goals of this study were to determine whether mice would adapt to a low-calorie flavored water gel as their sole source of hydration and whether the addition of acetaminophen, tramadol, meloxicam, or buprenorphine to...

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...

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...

Vonk, J., Truax, J., McGuire, M. C. 2022. A food for all seasons: Stability of food preferences in gorillas across testing methods and seasons. Animals 12(6), 685.

Decisions about which foods to use during training and enrichment for captive animals may be based on invalid assumptions about individuals’ preferences. It is important to assess the stability of food preferences given that one-time...

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...

Martins, T., Matos, A. F., Soares, J. et al. 2022. Comparison of gelatin flavors for oral dosing of C57BL/6J and FVB/N mice. JAALAS 61(1), 89-95.

Precise oral dosing in rodents is usually achieved by intragastric gavage. If performed incorrectly due to technical difficulties, inexperience, or animal resistance, oral gavage may have animal welfare implications such as esophageal and gastric rupture...

Hickman, D. L. 2022. Evaluation of carbon dioxide euthanasia of female Sprague Dawley rats alone or with unfamiliar conspecifics. JAALAS 61(2), 195-200.

Most studies evaluating methods of euthanasia to date have focused on the euthanasia of individual animals. However, larger chambers are commonly used to euthanize multiple cages of animals at once. This study evaluated the use...

Habenicht, L. M., Staley, A. W., Clancy, B. M. et al. 2022. Characterization of a jumping stereotypy in gerbils (Meriones unguiculatus) and assessment of opaque tubing enrichment on stereotypies and breeding. JAALAS 61(2), 149-158.

Mongolian gerbils can develop stereotypic behaviors, including corner digging. At our institution, gerbils also engage in repetitive corner jumping, which we sought to characterize as a potentially novel stereotypy in gerbils. We then attempted to...