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...

Jiron, J. M., Mendieta Calle, J. L., Castillo, E. J. et al. 2019. Comparison of isoflurane, ketamine-dexmedetomidine, and ketamine-xylazine for general anesthesia during oral procedures in rice rats (Oryzomys palustris). JAALAS 58(1), 40-49.

Rice rats (Oryzomys palustris) are an unconventional laboratory species that has been used to study photoperiodicity, periodontitis, and osteonecrosis of the jaw. Interventional procedures that require anesthesia, including oral procedures, are sometimes necessary in preclinical...

Sloman, K, A., Bouyoucos, I. A., Brooks, E. J. et al. 2019. Ethical considerations in fish research. Journal of Fish Biology 94(4), 556-577.

In this review, we focus primarily on the refinement of common methods used in fish research based on emerging knowledge with the aim of improving the welfare of fish used in scientific studies. We consider...

Mechelinck, M., Kupp, C., Krüger, J. C. et al. 2019. Oxygen inhalation improves postoperative survival in ketamine-xylazine anaesthetised rats: An observational study. PLOS ONE 14(12), e0226430.

A simple but reliable and safe anaesthetic procedure is required for surgical interventions in small rodents. Combined ketamine and xylazine injections are often used in rats for less invasive surgery, possibly with spontaneous breathing and...

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...

Ehrlich, O., Karamalakis, A., Krylov, A. J. et al. 2019. Clove oil and AQUI-S efficacy for zebrafish embryo, larva, and adult anesthesia. Zebrafish 16(5), 451-459.

Since the use of the zebrafish Danio rerio genetic model organism within the scientific research community continues to grow rapidly, continued procedural refinement to support high-quality, reproducible research and improve animal welfare remains an important...

Balko, J. A., Lindemann, D. M., Allender, M. C. et al. 2019. Evaluation of the anesthetic and cardiorespiratory effects of intramuscular alfaxalone administration and isoflurane in budgerigars (Melopsittacus undulatus) and comparison with manual restraint. Journal of the American Veterinary Medical Association 254(12), 1427-1435.

OBJECTIVE To evaluate the anesthetic and cardiorespiratory effects of IM alfaxalone and isoflurane administration in budgerigars (Melopsittacus undulatus) and compare use of these agents with use of manual restraint. ANIMALS 42 healthy budgerigars. PROCEDURES For...

Dholakia, U., Seddighi, R., Odunayo, A. et al. 2019. Prolonged anesthetic recovery after continuous infusion of midazolam in 2 domestic cats (Felis catus). Comparative Medicine 69(4), 321–326.

Two healthy research cats involved in a randomized, blinded prospective pharmacodynamics study evaluating midazolam continuous-rate infusion as a means to decrease sevoflurane concentrations experienced unexpectedly prolonged recoveries. Midazolam loading doses, infusion rates, and the targeted...

Dunford, K., Hakkesteeg, J., Wilson, C. 2019. Stiff as a board: Measuring rigor mortis in zebrafish. Animal Technology and Welfare 18(3), 203-205.

Schedule one killing (S1K) methods require a two-step process: a humane method of death, typically for Zebrafish an anaesthetic overdose and confirmation of death, such as confirmation of rigor mortis. There is widespread variation of...

Thurman, C. E., Rasmussen, S., Prestia, K. A. 2019. Effect of 3 euthanasia methods on serum yield and serum cortisol concentration in zebrafish (Danio rerio). JAALAS 58(6), 823–828.

Zebrafish are an important model in neuroscience and developmental biology and are also an emerging model in hematology and immunology. Little information is available for zebrafish regarding the physiologic impact of different euthanasia methods and...

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...

Lin, C.-H., Lo, P.-Y. 2018. Simple technique for aiding thoracic CT scanning of cats without general anaesthesia. Veterinary Record 182(7), 1-3.

Thoracic CT can provide additional diagnostic information in comparison to thoracic radiography for animals with respiratory diseases; however, the requirement of general anaesthesia can be of risk and may not be possible in cats with...

ter Horst, E. N., Krijnen, P. A. J., Flecknell, P. et al. 2018. Sufentanil–medetomidine anaesthesia compared with fentanyl/fluanisone–midazolam is associated with fewer ventricular arrhythmias and death during experimental myocardial infarction in rats and limits infarct size following reperfusion. Laboratory Animals 52(3), 271-279.

To improve infarct healing following myocardial infarction in humans, therapeutic interventions can be applied during the inflammatory response. Animal models are widely used to study this process. However, induction of MI in rodents is associated...

Schuster, C. J., Pang, D. S. J. 2018. Forced-air pre-warming prevents peri-anaesthetic hypothermia and shortens recovery in adult rats. Laboratory Animals 52(2), 142-151.

General anaesthesia disrupts thermoregulation in mammals, which can cause hypothermia. Decreases in core body temperature of 1℃ cause significant postoperative complications in humans, and peri-anaesthetic hypothermia in mice increases data variability, which can potentially increase...

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...

Wallace, C. K., Bright, L. A., Marx, J. O. et al. 2018. Effectiveness of rapid cooling as a method of euthanasia for young zebrafish (Danio rerio). JAALAS 57(1), 58-63.

Despite increased use of zebrafish (Danio rerio) in biomedical research, consistent information regarding appropriate euthanasia methods, particularly for embryos, is sparse. Current literature indicates that rapid cooling is an effective method of euthanasia for adult...

Hocking, A. J., Elliot, D., Hua, J. et al. 2018. Administering fixed oral doses of curcumin to rats through voluntary consumption. JAALAS 57(5), 508–512.

Curcumin, a polyphenol derived from turmeric, has a wide variety of therapeutic benefits including antiinflammatory, antioxidative, and chemopreventative effects. Oral gavage is widely performed to administer curcumin in laboratory rodents in several experimental models. Although...

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...

Raya, J., Neves Girardi , C. E., Hipólide, D. C. 2019. Corticosterone assimilation by a voluntary oral administration in palatable food to rats. Journal of Applied Animal Welfare Science 22(1), 37-41.

Drug delivery in research on nonhuman animals in the laboratory is still challenging because it is usually invasive and stressful. Stress-free voluntary oral drug administration in water lacks precise control of dose and timing of...

Hankenson, F. C., Marx, J. O., Gordon, C. J. et al. 2018. Effects of rodent thermoregulation on animal models in the research environment. Comparative Medicine 68(6), 425–438.

To best promote animal wellbeing and the efficacy of biomedical models, scientific, husbandry, and veterinary professionals must consider the mechanisms, influences, and outcomes of rodent thermoregulation in contemporary research environments. Over the last 2 decades...

Byrd, R., Boyd, S., Buckmaster, C. 2018. Rat thunder jacket— A zen experience. Laboratory Animal Science Professional 6(3) (September), 55-57.

Germ-free rats are fairly uncommon, relative to germ-free mice, and restraining these animals safely and effectively for compound administration and blood collection can be challenging. There are many commercially available varieties of restraint devices, but...

Barker, T. H., George, R. P., Howarth, G. S. et al. 2017. Assessment of housing density, space allocation and social hierarchy of laboratory rats on behavioural measures of welfare. PLOS ONE 12(9), e0185135.

Minimum space allowances for laboratory rats are legislated based on weight and stocking rates, with the understanding that increased housing density encourages crowding stress. However, there is little evidence for these recommendations, especially when considering...

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...

Pinelli, C., Leri, F., Turner, P. 2017. Long term physiologic and behavioural effects of housing density and environmental resource provision for adult male and female Sprague Dawley rats. Animals 7(6), 44.

There is considerable interest in refining laboratory rodent environments to promote animal well-being, as well as research reproducibility. Few studies have evaluated the long term impact of enhancing rodent environments with resources and additional cagemates...