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. 
Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Stevens, C., Finnegan, E., Clarkson, J. et al. 2020. Report of the 2019 RSPCA/UFAW Rodent Welfare meeting. Animal Technology and Welfare 19(2), 101-111.

The RSPCA/UFAW Rodent Welfare Group has held a one-day meeting every autumn for the last 26 years, so that its members can discuss current welfare research, exchange views on welfare issues, and share experiences of...

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...

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...

Butler, J. L., Kennerley, S. W. 2019. Mymou: A low-cost, wireless touchscreen system for automated training of nonhuman primates. Behaviour Research Methods 51, 2559–2572.

Training nonhuman primates (NHPs) to perform cognitive tasks is essential for many neuroscientific investigations, yet laboratory training is a time-consuming process with inherent limitations. Habituating NHPs to the laboratory staff and experimental equipment can take...

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...

Taniuchi, T., Ohgi, A., Nishikawa, M. 2019. Returning to home cage serves as an effective reward for maze learning in rats. Behavioural Processes 164, 175-177.

This study examined the effectiveness in rats of ‘returning to home cage’ as a reward for learning a Lashley III maze. Rats could return to their home cage directly (Direct HC group) or they could...

Leenaars, C. H. C., Pels, E. G. M., Joosten, R. N. J. M. A. et al. 2019. Wistar rats do not show preference for either of two commonly used nutritionally sound food rewards in a T-maze. Journal of Veterinary Behavior 31, 22-27.

Food rewards are commonly used as positive reinforcement in rodent behavioral experiments. Bioserv dustless precision pellets and Noyes formula P precision pellets are both used for this purpose in behavioral experiments in multiple laboratories, as...

Gray, H., Thiele, A., Rowe, C. 2019. Using preferred fluids and different reward schedules to motivate rhesus macaques (Macaca mulatta) in cognitive tasks. Laboratory Animals 53(4), 372–382.

Rhesus macaques (Macaca mulatta) used in behavioural neuroscience are often required to complete cognitively complex tasks, for which a high level of motivation is essential. To induce motivation, researchers may implement fluid-restriction protocols, whereby freely...

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...

Mason, S., Premereur, E., Pelekanos, V. et al. 2019. Effective chair training methods for neuroscience research involving rhesus macaques (Macaca mulatta). Journal of Neuroscience Methods 317, 82-93.

Background: Neuroscience research using macaques remains fundamental in our endeavours to understand how the human brain functions. Applying the refinement principle of the 3Rs is essential to optimise the monkeys’ welfare and still produces high...

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...

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...

Franklin, A. N., Martin, A. L., Brennan, C. R. et al. 2018. A comparison of desensitization techniques to train rhesus macaques to take food from a human. American Journal of Primatology 80(S1), 13 (40th Meeting of the American Society of Primatologists Scientific Program, Abstract #5).

Some primates express fear of or avoid interaction with humans, including accepting food. Counter‐conditioning training designed to reduce fear and increase the acceptance of food from a person's hand can reduce the stress an animal...

Coleman, K., Robertson, N. D. 2018. Training non-lactating rhesus macaques to act as foster mothers. American Journal of Primatology 80(S1), 34-35 (40th Meeting of the American Society of Primatologists Scientific Program, Abstract #94).

There can be psychological and physiological consequences resulting from nursery rearing rhesus macaques. To reduce the need for nursery rearing, orphaned infants are often placed with lactating foster mothers. Unfortunately, a supply of these lactating...

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...

Martin, A. L., Franklin, A. N., Perlman, J. E. et al. 2018. Systematic assessment of food item preference and reinforcer effectiveness: Enhancements in training laboratory-housed rhesus macaques. Behavioural Processes 157, 445-452.

The use of systematic preference assessments can enhance positive reinforcement training with captive animals. We found that the multiple stimulus without replacement (MSWO) technique identified food preferences in laboratory housed rhesus macaques, with raisins and...

Gray, H., Pearce, B., Thiele, A. 2017. The use of preferred social stimuli as rewards for rhesus macaques in behavioural neuroscience. PLOS ONE 12(5), e0178048.

Macaques are often motivated to perform in neuroscientific experiments by implementing fluid restriction protocols. Daily access to water is controlled and the monkeys are rewarded with droplets of fluid for performing correct trials in the...

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...

Kemp, C., Thatcher, H., Farningham, D. et al. 2017. A protocol for training group-housed rhesus macaques (Macaca mulatta) to cooperate with husbandry and research procedures using positive reinforcement. Applied Animal Behaviour Science 197, 90-100.

There has been increased recognition of the 3Rs in laboratory animal management over the last decade, including improvements in animal handling and housing. For example, positive reinforcement is now more widely used to encourage primates...

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...

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...