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. 
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...

Dutton III, J. W., Artwohl, J. E., Huang, X. et al. 2019. Assessment of pain associated with the injection of sodium pentobarbital in laboratory mice (Mus musculus). JAALAS 58(3), 373-379.

The AVMA Guidelines for the Euthanasia of Animals considers injection of barbiturates to be an acceptable method of euthanasia in rodents but states there is a potential for pain when administered intraperitoneally. This study examined...

Moffitt, A. D., Brignolo, L. L., Ardeshir, A. et al. 2019. The role of emotional contagion in the distress exhibited by grouped mice exposed to CO2. JAALAS 58(4), 430-437.

The 2013 AVMA Guidelines for the Euthanasia of Animals recommends a chamber volume displacement rate of 10% to 30% per minute (v/min) when euthanizing small laboratory rodents with CO2. Group euthanasia of mice is a...

Windsor, Z., Bate, S. T. 2019. Assessing the safety and suitability of nesting material for singly housed mice with surgically fitted head plates. Heliyon 5(7), e02097.

Nesting material, for example shredded paper, is a common form of enrichment for laboratory mice. However, there has been limited research performed regarding its apparent safety when given to mice fitted with exteriorised devices such...

Gjendal, K., Lund Ottesen, J., Olsson, I. A. S. et al. 2019. Burrowing and nest building activity in mice after exposure to grid floor, isoflurane or ip injections. Physiology & Behavior 206, 59-66.

Burrowing and nest building are examples of highly motivated innate behaviours in rodents. Assessments based on these behaviours can be used as non-invasive indicators of pain, distress and suffering. In this study, we investigated the...

Gent, T. C., Detotto, C., Vyssotski, A. L. et al. 2018. Epileptiform activity during inert gas euthanasia of mice. PLOS ONE 13(4), e0195872.

Carbon dioxide (CO2) is one of the most commonly used euthanasia agents for mice, yet it is highly aversive and nociceptive. Inert gases are a possible alternative, however there are qualitative reports of seizures resulting...

Dudley, E. S., Boivin, G. P. 2018. Evaluation of a commercially available euthanasia solution as a voluntarily ingested euthanasia agent in laboratory mice. JAALAS 57(1), 30-34.

All currently accepted methods of euthanasia for laboratory mice involve some degree of stress, fear, anxiety, or pain. We evaluated the voluntary oral administration of a euthanasia drug in 99 male and 81 female mice...

Lahger, C., Laska, M. 2018. Behavioral responses of CD-1 mice to conspecific and heterospecific blood odors and to a blood odor component. Physiology & Behavior 184, 2015-210.

The odor of blood may have both aversive and attractive properties for mammals, depending on the species of the odor donor and the species perceiving the odor. To better understand the informational content of blood...

Galvin, M., Lallo, A., Brown, S. et al. 2018. Refinement of tumour passage by optimisation of the tissue disaggregation protocol. Animal Technology and Welfare 17(2), 101-103.

Surgical implantation of tumour pieces has been used regularly in the passage of tumour models. This involves an invasive surgical procedure, carried out under anaesthesia, ensuring mice have adequate pain relief and peri-operative care. The...

Allen, L. 2018. Refinements to animal husbandry for continuous infusion dosing in Beagle dogs. Animal Technology and Welfare 17(2), 126-127.

At Envigo we are contracted by our customers to conduct studies, usually to evaluate the safety of new drugs and chemicals. A rodent and non-rodent species are usually involved in this testing with the method...

Fisher, P. 2018. Improving safety assessment studies by the introduction of a refined ECG vest for dogs. Animal Technology and Welfare 17(1), 48-49.

This study describes a refined/modified vest and jacket worn by dogs to capture ECG data after they are given a compound of interest. The modified vest and jacket prevents dogs from chewing the leads and...

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...

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...

Deckers, N., Ruigrok, C. A., Verhoeve, H. P. et al. 2018. Comparison of pain response after subcutaneous injection of two maropitant formulations to beagle dogs. Veterinary Record Open 5(1), e000262.

The antiemetic maropitant, with metacresol as preservative (Cerenia, Zoetis), has been associated with pain after subcutaneous injection in dogs and cats. Recently, a generic formulation containing benzyl alcohol was authorised (Prevomax, Le Vet). Benzyl alcohol...

Tavera-Mendoza, L. E., Brown, M. 2017. A less invasive method for orthotopic injection of breast cancer cells into the mouse mammary gland. Laboratory Animals 51(1), 85-88.

Breast cancer is the most common type of cancer diagnosed in women, and the second most common cause of cancer-related deaths in women in North America. The use of laboratory mice in research is an...

Larsen, R. A., Peveler, J. L., Klutzke, J. B. et al. 2017. Effects of daily restraint with and without injections on skeletal properties in C57BL/6NHsd mice. Lab Animal 46(7), 299-301.

Studies typically involve groups of animals that are injected with placebo compounds. As there are studies that demonstrate that restraint and injection can affect behavior and corticosteroid levels in rodents, the basis of such placebo...

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...

Hubbard, J. S., Chen, P. H., Boyd, K. L. 2017. Effects of repeated intraperitoneal injection of pharmaceutical-grade and nonpharmaceutical-grade corn oil in female C57BL/6J mice. JAALAS 56(6), 779-785.

Due to potential adverse effects on animal wellbeing, the use of nonpharmaceutical-grade substances in animal research must be scientifically justified in cases where a pharmaceutical-grade version of the substance exists. This requirement applies to all...

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...

Bailey, C. 2017. Refinements in housing during data capture in long term Safety Pharmacology dogs. Animal Technology and Welfare 16(2), 147-149.

Dogs are individually housed when collecting data for ECG studies to avoid any cross talk between transmitted signals (generally for a 24 hour recording period). Each implant is set at a certain frequency which transmits...

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...

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...

Jang, Y., Park, Y. E., Yun, C.-W. et al. 2016. The vest-collar as a rodent collar to prevent licking and scratching during experiments. Laboratory Animals 50(4), 296-304.

Various types of restraint collars have been used for research animals, and the Elizabethan collar (E-collar) is the most commonly used. However, animals can be choked by the E-collar or they tend to remove it...