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. 
Prior, H., Blunt, H., Crossman, L. et al. 2021. Refining procedures within regulatory toxicology studies: Improving animal welfare and data. Animals 11(11), 3057.

During the development of potential new medicines or agrochemicals, an assessment of the safety profile to humans and environmental species is conducted using a range of different in silico and in vitro techniques in conjunction...

Zemanova, M. A. 2021. Noninvasive genetic assessment is an effective wildlife research tool when compared with other approaches. Genes 12(11), 1672.

Wildlife research has been indispensable for increasing our insight into ecosystem functioning as well as for designing effective conservation measures under the currently high rates of biodiversity loss. Genetic and genomic analyses might be able...

de A. P. Ramos, G., de Azevedo, C. S., Jardim, T. H. A. et al. 2021. Temperament in captivity, environmental enrichment, flight ability, and response to humans in an endangered parrot species. Journal of Applied Animal Welfare Science 24(4), 379-391.

Temperament assessment is useful in reintroduction programs. Reactivity to humans and flight ability are also important behavioral aspects for captive parrots candidates to reintroduction. The study aimed: a) to evaluate if behavioral responses to environmental...

Brunt, M. W., Améndola, L., Weary, D. M. 2021. Attitudes of laboratory animal professionals and researchers towards carbon dioxide euthanasia for rodents and perceived barriers to change. Laboratory Animals 55(6), 531-539.

Evidence indicates that carbon dioxide (CO2) induces negative affective states (including anxiety, fear and distress) in laboratory rodents, but many countries still accept it for euthanasia. Alternative methods (e.g. inhalant anaesthetic) may represent a refinement...

Frost, K., Shah, M., Leung , V. S. Y. et al. 2020. Aversion to desflurane and isoflurane in Sprague-Dawley rats (Rattus norvegicus). Animals 10(6), 950.

Carbon dioxide and isoflurane are widely used for killing rats, yet may not truly achieve “euthanasia”, because they elicit aversion. The inhalant anesthetic desflurane is faster acting than isoflurane, representing a potential refinement. Using an...

Ballantine, A., Rodgers, D., Watts, C. et al. 2020. The cotton rat – a new challenge. Animal Technology and Welfare 19(1), 92-95.

This poster describes how the Animal Technologists at Envigo adapted their current practices and procedures for a new species at their laboratory: the cotton rat. The paper describes cotton rat biology and behaviour; housing; environmental...

Améndola, L., Weary, D. M. 2020. Understanding rat emotional responses to CO2. Translational Psychiatry 10, 253.

The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO2) exposure. The studies reviewed show that CO2 exposure is aversive to rats, and that rats respond to CO2...

Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss...

Shomer, N. H., Allen-Worthington, K. H., Hickman, D. L. et al. 2020. Review of rodent euthanasia methods. JAALAS 59(3), 242–253.

The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the...

Laferriere, C. A., Pang, D. S. 2020. Review of intraperitoneal injection of sodium pentobarbital as a method of euthanasia in laboratory rodents. JAALAS 59(3), 254–263.

Euthanasia is one of the most commonly performed procedures in biomedical research, involving tens of millions of animals in North America and Europe every year. The use of sodium pentobarbital, injected intraperitoneally, for killing rodents...

Bessa Ferreira, V. H., De Paiva Fonseca, E., Chagas, Correia Santos Das, A. C. et al. 2020. Personality traits modulate stress responses after enclosure change of captive capuchin monkeys (Sapajus libidinosus). Applied Animal Behaviour Science 232, 105111.

Husbandry procedures may cause behavioral and physiological changes to animals living in captivity. However, an individual’s reaction is not uniform and may be related to different coping strategies. In this study, we analyzed whether and...

Tilley, C. A., Carreño Gutierrez, H., Sebire, M. et al. 2020. Skin swabbing is a refined technique to collect DNA from model fish species. Scientific Reports 10(1), 18212.

Model fish species such as sticklebacks and zebrafish are frequently used in studies that require DNA to be collected from live animals. This is typically achieved by fin clipping, a procedure that is simple and...

Cohen, S., Kwok, M., Huang, J. 2020. Humane euthanasia of guinea pigs (Cavia porcellus) with a penetrating spring-loaded captive bolt. Animals 10(8), 1356.

Guinea pigs (Cavia porcellus) have been used in research since the 19th century to collect data due to their physiological similarities to humans. Today, animals perform a vital role in experiments and concerns for laboratory...

Kulkarni, S., Hickman, D. 2020. Isoflurane and carbon dioxide elicit similar behavioral responses in rats. Animals 10(8), 1431.

Euthanasia in rodents is an ongoing topic of debate due to concerns regarding the aversive nature of gases with anesthetic properties such as carbon dioxide (CO2) and isoflurane. The aim of this study was to...

Van Wijk, H., Haida, D., Duncan, C. et al. 2020. Surgery refinements improve success rates in rat bile collection. Animal Technology and Welfare 19(3), 251-254.

This poster compares the model success rates using 2 different housing regimes during recovery from surgery. Catheters were placed in the bile duct to collect bile; a second catheter was secured into the duodenum where...

Stanger, K. J., Kells, N. J., Fisher, A. D. et al. 2019. Evaluation of euthanasia of sheep with intravenous saturated salt solutions to enable the collection of whole, intact brains. Animal Welfare 28(4), 397-406.

Captive bolts or firearms are unsuitable for euthanasia of livestock when an intact brain is required for diagnostics. Injectable barbiturates can be used, but this method carries risk of poisoning animals eating the carcase. Intravenous...

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...

Domingues, R. R., Garrone-Neto, D., Hilsdorf, A. W. S. et al. 2019. Use of mucus as a non-invasive sampling method for DNA barcoding of stingrays and skates (batoid elasmobranchs). Journal of Fish Biology 94(3), 512-516.

In this study we tested the use of mucus from five species of Neotropical marine batoid elasmobranchs to extract genomic DNA for barcoding and phylogenetic analysis. The DNA from all individuals sampled was successfully amplified...

Anders, N., Roth, B., Grimsbø, E. et al. 2019. Assessing the effectiveness of an electrical stunning and chilling protocol for the slaughter of Atlantic mackerel (Scomber scombrus). PLOS ONE 14(9), e0222122.

Inducing unconsciousness in fish using electrical stunning prior to slaughter may improve fish welfare and fillet quality if such practises can be disseminated into wild capture fisheries. The objectives of this study were to: 1)...

Améndola, L., Ratuski, A., Weary, D. M. 2019. Variation in the onset of CO2-induced anxiety in female Sprague Dawley rats. Scientific Reports 9, 19007.

Carbon dioxide (CO2) is commonly used to kill laboratory rats. Rats find CO2 aversive and aversion varies between individuals, indicating that rats vary in CO2 sensitivity. Healthy humans experience feelings of anxiety at concentrations similar...

Kells, N. J., Beausoleil, N. J., Sutherland, M. A. et al. 2018. Electroencephalographic responses of anaesthetised rats to carbon dioxide inhalation. Animal Welfare 27(3), 215-223.

Exposure to high concentrations of CO2 is a common means of stunning and killing laboratory rodents. However, there is concern regarding the potential for animals to have aversive experiences, such as pain or breathlessness, prior...

Golledge, H., Carter, E. 2018. Welfare of fish farmed in the EU during transport and at slaughter. Animal Welfare 27(3), 287-288.

This Report, commissioned by the European Commission, summarises the current state of transport and slaughter practices in the aquaculture industry within eleven case-study countries in the European Economic Area (EAA). Comparisons are also made with...

Khoo, S. Y.-S., Lay, B. P. P., Joya, J. et al. 2018. Local anaesthetic refinement of pentobarbital euthanasia reduces abdominal writhing without affecting immunohistochemical endpoints in rats. Laboratory Animals 52(2), 152-162.

Sodium pentobarbital is a commonly used agent for euthanizing laboratory rats, however its high pH can cause abdominal discomfort after intraperitoneal injection. Previous studies suggest that the addition of a local anaesthetic may alleviate this...

Grist, A., Lines, J., Knowles, T. et al. 2018. The use of a mechanical non-penetrating captive bolt device for the euthanasia of neonate lambs. Animals 8(4), 49.

A non-penetrating captive bolt device, powered by a 1-grain 0.22″ cartridge delivering a calculated kinetic energy of 47 Joules was tested as a euthanasia method on 200 neonate lambs (Ovis aries) of 4.464 kg (SD...