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. 
Balko, J. A., Oda, A., Posner, L. P. 2018. Use of tricaine methanesulfonate or propofol for immersion euthanasia of goldfish (Carassius auratus). Journal of the American Veterinary Medical Association 252(12), 1555-1561.

OBJECTIVE To substantiate current AVMA guidelines for immersion euthanasia of goldfish (Carassius auratus) with tricaine methanesulfonate (TMS), determine whether immersion in propofol at 5 times its immersion anesthesia concentration for 30 minutes is sufficient for...

Creamer-Hente, M. A., Lao, F. K., Dragos, Z. P. et al. 2018. Sex- and strain-related differences in the stress response of mice to CO₂ euthanasia. JAALAS 57(5), 513–519.

The 2013 edition of the AVMA Guidelines for the Euthanasia of Animals recommends a 10% to 30% volume displacement rate (VDR) per minute for CO2 euthanasia of rodents. Here we sought to evaluate behavior and...

Hickman D. L. 2018. Interpreting neuroendocrine hormones, corticosterone, and blood glucose to assess the wellbeing of anesthetized rats during euthanasia. JAALAS 57(6), 725–728.

Current recommendations for assessing animal wellbeing during euthanasia suggest that measuring neuroendocrine hormones—such as ACTH, noradrenaline, and adrenaline—is preferable to measuring corticosterone and blood glucose because of the sensitivity of neuroendocrine hormones to the acute...

Hickman D. L. 2018. Home cage compared with induction chamber for euthanasia of laboratory rats. JAALAS 57(6), 729–733.

This study compared behavioral and physiologic changes in Sprague–Dawley and Brown Norway rats that were euthanized by using a 30% volume displacement rate of CO2 in either their home cage or an induction chamber; rats...

Marquardt, N., Feja, M., Hünigen, H. et al. 2018. Euthanasia of laboratory mice: Are isoflurane and sevoflurane real alternatives to carbon dioxide? PLOS ONE 13(9), e0203793.

In the European Union (EU) millions of laboratory mice are used and killed for experimental and other scientific purposes each year. Although controversially discussed, the use of carbon dioxide (CO2) is still permitted for killing...

Köhler, A., Collymore, C., Finger-Baier, K. et al. 2017. Report of Workshop on Euthanasia for Zebrafish—A Matter of welfare and science. Zebrafish 14(6), 547-551.

The increasing importance of zebrafish as a biomedical model organism is reflected by the steadily growing number of publications and laboratories working with this species. Regulatory recommendations for euthanasia as issued in Directive 2010/63/EU are...

Peric, T., Comin, A., Corazzin, M. et al. 2017. Relocation and hair cortisol concentrations in New Zealand White rabbits. Journal of Applied Animal Welfare Science 20(1), 1-8.

To investigate how long relocation modified hair cortisol concentrations in New Zealand white rabbits, 19 rabbits were subjected to a change in their breeding facility at the beginning of the trial and then were kept...

Walsh, J., Percival, A., Turner, P. 2017. Efficacy of blunt force trauma, a novel mechanical cervical dislocation device, and a non-penetrating captive bolt device for on-farm euthanasia of pre-weaned kits, growers, and adult commercial meat rabbits. Animals 7(12), 100.

The commercial meat rabbit industry is without validated on-farm euthanasia methods, potentially resulting in inadequate euthanasia protocols. We evaluated blunt force trauma (BFT), a mechanical cervical dislocation device (MCD), and a non-penetrating captive bolt device...

Boivin, G. P., Hickman, D. L., Creamer-Hente, M. A. et al. 2017. Review of CO2 as a euthanasia agent for laboratory rats and mice. JAALAS 56(5), 491-499.

Selecting an appropriate, effective euthanasia agent is controversial. Several recent publications provide clarity on the use of CO2 in laboratory rats and mice. This review examines previous studies on CO2 euthanasia and presents the current...

de Souza Dyer, C., Brice, A. K., Marx, J. O. 2017. Intraperitoneal administration of ethanol as a means of euthanasia for neonatal mice (Mus musculus). JAALAS 56(3), 299-306.

The humane euthanasia of animals in research is of paramount importance. Neonatal mice frequently respond differently to euthanasia agents when compared with adults. The AVMA's Guidelines for the Euthanasia of Animals includes intraperitoneal injection of...

Boivin, G. P., Bottomley, M. A., Schiml, P. A. et al. 2017. Physiologic, behavioral, and histologic responses to various euthanasia methods in C57BL/6NTac male mice. JAALAS 56(1), 69-78.

Rodent euthanasia using exposure to increasing concentrations of CO2 has come under scrutiny due to concerns of potential pain during the euthanasia process. Alternatives to CO2, such as isoflurane and barbiturates, have been proposed as...

Simpson, D. 2017. Investigation of transportation on rat acclimatisation using novel cage side recording equipment (Rodent Big Brother). Animal Technology and Welfare 16(1), 1-12.

The transportation of animals from supplier to experimental facility is one of the biggest stressors to animals in research. Transportation unavoidably causes stress and when the animals arrive at the testing facility they require a...

Guedes, S. R., Valentim, A. M., Antunes, L. M. 2017. Mice aversion to sevoflurane, isoflurane and carbon dioxide using an approach-avoidance task. Applied Animal Behaviour Science 189, 91-97.

Euthanasia of laboratory animals is one of the main concerns for animal welfare, especially the use of carbon dioxide (CO2) which has been described to induce aversive-like behaviours. In order to refine mass euthanasia in...

Stevens, C. H., Croft, D. P., Paull, G. C. et al. 2017. Stress and welfare in ornamental fishes: What can be learned from aquaculture? Journal of Fish Biology 91(2), 409-428.

The ornamental fish trade is estimated to handle up to 1.5 billion fishes. Transportation and handling of fishes imposes a range of stressors that can result in mortality at rates of up to 73%. Given...

Lidster, K., Readman, G. D., Prescott, M. J. et al. 2017. International survey on the use and welfare of zebrafish Danio rerio in research. Journal of Fish Biology 90(5), 1891-1905.

A survey was conducted regarding zebrafish Danio rerio use for scientific research with a focus on: anaesthesia and euthanasia; housing and husbandry; breeding and production; refinement opportunities. A total of 98 survey responses were received...

Bermejo-Poza, R., De la Fuente, J., Pérez, C. 2016. Reducing the effect of pre-slaughter fasting on the stress response of rainbow trout (Oncorhynchus mykiss). Animal Welfare 25(3), 339-346.

Fasting is commonly used in aquaculture to empty the gut before slaughter, but little is known about how feeding frequency before fasting affects the stress response of trout. To find out more, 240 rainbow trout...

Valentim, A. M., Guedes, S. R., Pereira, A. M. et al. 2016. Euthanasia using gaseous agents in laboratory rodents. Laboratory Animals 50(4), 241-253.

Several questions have been raised in recent years about the euthanasia of laboratory rodents. Euthanasia using inhaled agents is considered to be a suitable aesthetic method for use with a large number of animals simultaneously...

Powell, K., Ethun, K., Taylor, D. K. 2016. The effect of light level, CO2 flow rate, and anesthesia on the stress response of mice during CO2 euthanasia. Lab Animal 45(10), 386-395.

Euthanasia protocols are designed to mitigate the stress experienced by animals, and an environment that induces minimal stress helps achieve that goal. A protocol that is efficient and practical in a typical animal research facility...

Hawkins, P., Prescott, M., Carbone, L. et al. 2016. A good death? Report of the second Newcastle meeting on laboratory animal euthanasia. Animals 6(9), 50.

Millions of laboratory animals are killed each year worldwide. There is an ethical, and in many countries also a legal, imperative to ensure those deaths cause minimal suffering. However, there is a lack of consensus...

Hickman, D., Fitz, S., Bernabe, C. et al. 2016. Evaluation of low versus high volume per minute displacement CO2 methods of euthanasia in the induction and duration of panic-associated behavior and physiology. Animals 6(8), 45.

Current recommendations for the use of CO 2 as a euthanasia agent for rats require the use of gradual fill protocols (such as 10% to 30% volume displacement per minute) in order to render the...

Zatroch, K. K., Knight, C. G., Reime, J. N. et al. 2017. Refinement of intraperitoneal injection of sodium pentobarbital for euthanasia in laboratory rats (Rattus norvegicus). BMC Veterinary Research 13, 60.

Background: The Canadian Council on Animal Care and American Veterinary Medical Association classify intraperitoneal (IP) pentobarbital as an acceptable euthanasia method in rats. However, national guidelines do not exist for a recommended dose or volume...

Moody, C. M., Makowska, I. J., Weary, D. M. 2015. Testing three measures of mouse insensibility following induction with isoflurane or carbon dioxide gas for a more humane euthanasia. Applied Animal Behaviour Science 163, 183-87.

Laboratory mice are commonly killed via exposure to gradually increasing concentrations of isoflurane and carbon dioxide (CO2) gas. Once rendered insensible using isoflurane or CO2, a high concentration of CO2 is used to decrease time...

Boulanger Bertolus, J., Nemeth, G., Makowska, I. J. et al. 2015. Rat aversion to sevoflurane and isoflurane. Applied Animal Behaviour Science 164, 73-80.

Virtually all rodents used in research are eventually euthanized. Best practice is to anaesthetize these animals before euthanasia using a halogenated anaesthetic such as isoflurane. Exposure to isoflurane is aversive, but less so than exposure...

Wong, D., Makowska, I. J., Weary, D. M. 2013. Rat aversion to isoflurane versus carbon dioxide. Biology Letters 9(1), 20121000.

Some experts suggest that sedation of laboratory rodents with isoflurane before euthanasia with carbon dioxide (CO2) is a humane alternative to euthanasia with CO2 alone, but little research has compared aversion with these agents. Albino...

Chisholm, J., De Rantere D., Fernandez, N. J. et al. 2013. Carbon dioxide, but not isoflurane, elicits ultrasonic vocalizations in female rats. Laboratory Animals 47(4), 324-7.

Gradual filling of a chamber with carbon dioxide is currently listed by the Canadian Council on Animal Care guidelines as a conditionally acceptable method of euthanasia for rats. Behavioural evidence suggests, however, that exposure to...