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. 
Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be...

Weaver, H. L., Carbaugh, C. M., Madejczyk, M. S. et al. 2024. Comparison of tricaine methanesulfonate (MS-222) and alfaxalone anesthesia in zebrafish (Danio rerio). JAALAS 63(1), 74–80.

The research use of zebrafish has risen exponentially over the past decade while anesthetic options have remained largely unchanged.6 ricaine methanesulfonate (MS-222) is widely accepted as an anesthetic for routine husbandry procedures, however it has...

Eeza, M. N. H., Singer, R., Ding, Y. et al. 2023. Probing microstructural changes in muscles of leptin-deficient zebrafish by non-invasive ex-vivo magnetic resonance microimaging. PLOS ONE 18(4), e0284215.

Leptin is a hormone that plays a key role in controlling food intake and energy homeostasis. Skeletal muscle is an important target for leptin and recent studies have shown that leptin deficiency may lead to...

Evans, L., Brooks, G. C., Anderson, M. G. et al. 2023. Environmental complexity and reduced stocking density promote positive behavioral outcomes in broiler chickens. Animals 13(13), 2074.

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD)...

Malik, A., Zavadil, J. A., Geusz, M. E. 2023. Using bioluminescence to image gene expression and spontaneous behavior in freely moving mice. PLOS ONE 18(1), e0279875.

Bioluminescence imaging (BLI) of gene expression in live animals is a powerful method for monitoring development, tumor growth, infections, healing, and other progressive, long-term biological processes. BLI remains an effective approach for reducing the number...

Palumbo, G., Kunze, L. H., Oos, R. et al. 2023. Longitudinal studies on Alzheimer disease mouse models with multiple tracer PET/CT: Application of reduction and refinement principles in daily practice to safeguard animal welfare during progressive aging. Animals 13(11), 1812.

Longitudinal studies on mouse models related to Alzheimer disease (AD) pathology play an important role in the investigation of therapeutic targets to help pharmaceutical research in the development of new drugs and in the attempt...

Sen Sarma, O., Frymus, N., Axling, F. et al. 2023. Optimizing zebrafish rearing−Effects of fish density and environmental enrichment. Frontiers in Behavioral Neuroscience 17, 1204021.

Despite its popularity in research, there is very little scientifically validated knowledge about the best practices on zebrafish (Danio rerio) husbandry, which has led to several facilities having their own husbandry protocols. This study was...

Buhr, P., Kolstrup, S., Nikolajsen, L.-L. et al. 2023. The anaesthetic effects of ketamine/xylazine/midazolam in C57Bl/6JRj mice. Scandinavian Journal of Laboratory Animal Science 49, 21–27.

We wished to improve the efficacy and safety of ketamine/xylazine anaesthesia in C57Bl/6JRj mice and achieve a surgical anaesthesia lasting 20-30 minutes, aiming at fewer anaesthesia related deaths and using the subcutaneous injection route to...

Hanh, H. Q., Phuong, N. T., Tien, N. D. et al. 2023. Effects of stocking density in group cages on egg production, profitability, and aggressive pecking of hens. Journal of Applied Animal Welfare Science 26(3), 374–385.

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We...

Webb, J. K., Keller, K. A., Chinnadurai, S. K. et al. 2023. Use of alfaxalone in bearded dragons (Pogona vitticeps): Optimizing pharmacodynamics and evaluating cardiogenic effects via echocardiography. Journal of the American Veterinary Medical Association 261(1), 126–131.

OBJECTIVE Bearded dragons (Pogona vitticeps), a popular zoological companion species, frequently require sedation for procedures. A novel formulation of alfaxalone with preservatives was FDA approved for 28-day use after the vial is breached. Research has...

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...

Mocz, F., Michel, V., Janvrot, M. et al. 2022. Positive effects of elevated platforms and straw bales on the welfare of fast-growing broiler chickens reared at two different stocking densities. Animals 12(5), 542.

In conventional rearing systems, fast-growing broiler chickens commonly experience welfare issues, such as contact dermatitis, walking difficulties or a lack of expression of species-specific behaviours. Enriching their environment may be a way to improve their...

Leyden, C., Brüggemann, T., Debinski, F. et al. 2022. Efficacy of tricaine (MS-222) and hypothermia as anesthetic agents for blocking sensorimotor responses in larval zebrafish. Frontiers in Veterinary Science 9, 864573.

Tricaine, or MS-222, is the most commonly used chemical anesthetic in zebrafish research. It is thought to act via blocking voltage-gated sodium channels, though its mechanism of action, particularly at the neuronal level, is not...

Davies, J. R., Purawijaya, D. A., Bartlett, J. M. et al. 2022. Impact of refinements to handling and restraint methods in mice. Animals 12(17), 2173.

There is increasing evidence that, compared to non-aversive handling methods (i.e., tunnel and cupping), tail handling has a negative impact on mouse welfare. Despite this evidence, there are still research organisations that continue to use...

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...

Barkus, C., Bergmann, C., Branco, T. et al. 2022. Refinements to rodent head fixation and fluid/food control for neuroscience. Journal of Neuroscience Methods 381, 109705.

The use of head fixation in mice is increasingly common in research, its use having initially been restricted to the field of sensory neuroscience. Head restraint has often been combined with fluid control, rather than...

Scariot, P. P., Gobatto, C. A., Polisel, E. E. et al. 2022. Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood. Laboratory Animals 56(4), 344-355.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging...

Chen, T., Zhou, Z.-Y., Liu, J.-Y. et al. 2022. Impact of partial bile duct ligation with or without repeated magnetic resonance imaging examinations in mice. Scientific Reports 12(1), 21014.

Partial bile duct ligation (pBDL) is considered a well-tolerated cholestatic model. Magnetic resonance imaging (MRI) is one of the most widely used tools in noninvasive imaging. However, no systematic studies have reported the possible effects...

Saraiva, J. L., Rachinas-Lopes, P., Arechavala-Lopez, P. 2022. Finding the “golden stocking density”: A balance between fish welfare and farmers’ perspectives. Frontiers in Veterinary Science 9, 930221.

The effects of stocking density on fish welfare are complex and involve many interacting parameters. This complex relationship between fish welfare, stocking density and influencing factors make it challenging to define a specific optimal (“golden”)...

Schwarzer, A., Erhard, M., Schmidt, P. et al. 2022. Effects of stocking rate and environmental enrichment on the ontogeny of pecking behavior of laying hen pullets confined in aviary compartments during the first 4 weeks of life. Animals 12(19), 2639.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first...

van der Eijk, J. A. J., Gunnink, H., Melis, M. et al. 2022. Reducing stocking density benefits behaviour of fast- and slower-growing broilers. Applied Animal Behaviour Science 257, 105754.

The broiler industry has come under sustained pressure from welfare organizations to improve broiler welfare. Breed and stocking density are important factors for broiler welfare and are often specified as criteria for higher welfare systems...

Mumm, L. E., Mans, C. 2022. Evaluation of dexmedetomidine-midazolam sedation in budgerigars (Melopsittacus undulatus). Journal of the American Veterinary Medical Association 260(10), 1194–1199.

OBJECTIVE To evaluate the sedative effects of IM administration of a high or low dose of dexmedetomidine in combination with midazolam in budgerigars (Melopsittacus undulatus). ANIMALS 20 healthy adult budgerigars. PROCEDURES In a prospective, randomized...

Huss, M. K., Pacharinsak, C. 2022. A review of long-acting parenteral analgesics for mice and rats. JAALAS 61(6), 595–602.

Appropriate analgesia is a crucial part of rodent postoperative and postprocedural pain. Providing appropriate analgesia is an ethical obligation, a regulatory requirement, and an essential element of obtaining quality scientific results and conducting reproducible data...

Owen, J. P., Kelsh, R. N. 2021. A suitable anaesthetic protocol for metamorphic zebrafish. PLOS ONE 16(3), e0246504.

Zebrafish are frequently used as a means to investigate development. These studies increasingly require repeated anaesthesia of zebrafish during juvenile (i.e. metamorphic) stages. The effects of anaesthesia during this time remain poorly studied. The aim...

Phillips, H. N., Heins, B. J. 2021. Effects of outdoor stocking density on growth, feather damage and behavior of slow-growing free-range broilers. Animals 11(3), 688.

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed...