Deb Hickman

• DVM, MS, DACLAM, DACAW
• Global Director at AAALAC International

Neonatal rodents undergo anesthesia for numerous procedures and for euthanasia by anesthetic overdose. However, data regarding whether neonatal anesthesia is humane are limited. Hypothermia (cryoanesthesia) is the most commonly used anesthetic protocol for neonatal rats 10 d of age or younger. However, hypothermia has recently been restricted in se...

Objective: The objective of this review is to systematically map and collate the available scientific evidence on methods used to assess laboratory mouse welfare, with a focus on those methods that are non-invasive and practical for use in day-today welfare assessment. Introduction: The number of mice used globally in biomedical research is signifi...

Minimization of potential pain and distress of rodents undergoing euthanasia is a touchstone of veterinary clinical medicine. Evaluation of this issue in postweanling rodents has supported revisions to the AVMA (American Veterinary Medical Association) Guidelines on Euthanasia in 2020. However, relatively little information is available on humane a...

Neonatal rodents undergo anesthesia for numerous procedures and for euthanasia by anesthetic overdose. However, data regarding whether neonatal anesthesia is humane are limited. Hypothermia (cryoanesthesia) is the most commonly used anesthetic protocol for neonatal rats 10 d of age or younger. However, hypothermia has recently been restricted in se...

When using an anesthetic overdose to euthanize laboratory rodents, a secondary method of euthanasia is recommended to ensure that the apparent death is irreversible. This secondary method usually is accomplished through the collection of tissues that are required to complete the research project. However, frequently laboratory rodents must be eutha...

Multiple recent surveys have examined the prevalence of female first or senior authors on publications for various scientificand medical disciplines. First and senior authorships are significant achievements for purposes of professional advancement, especially in academia. Such surveys can also provide information regarding diversity and inclusion....

Survival rodent surgery requires the use of sterile instruments for each animal, which can be challenging when performing multiple surgeries on batches of animals. Glass bead sterilizers (GBS) are widely considered to facilitate this practice by sterilizing the tips of the instruments between animals. However, other disciplines have raised question...

Most studies evaluating methods of euthanasia to date have focused on the euthanasia of individual animals. However, largerchambers are commonly used to euthanize multiple cages of animals at once. This study evaluated the use of a commerciallyavailable system for euthanasia of 1, 2, or 4 cages containing an individual female Sprague-Dawley rat usi...

Background: Chronic stress and stress related pathologies such as major depressive disorder are significant risk factors for Alzheimer's disease and related dementia. Stress induced activation of the hypothalamic pituitary axis upregulate glucocorticoid (GC) secretion. Subsequent GC resistance and lack of GR mediated cellular responses has been as...

Rotational outbred adult rats, phenotypically selected to prefer drinking alcohol (“P” rats) frequently present with selfinflicted wounds and ulcerative dermatitis, similar to that seen in C57BL/6 mice. Historically, veterinary interventions used to address this clinical condition have included triple antibiotic ointment (TABO), Columbia wound powd...

The AVMA Guidelines on Euthanasia state that, to decrease potential distress of animals, the home cage should be used forthe euthanasia of mice. The current study evaluated this recommendation by comparing behavioral and physiologic changesin ICR and SJL mice that were euthanized by using a 30% volume per minute displacement rate of 100% CO2 in eit...

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 expand upon previously published work evaluating the aversiveness of CO2 by introducing an isoflurane treatment group in parallel. Aversion wa...

The use of animal models remains critical in preclinical and translational research. The reliability of the animal models and aspects of their validity is likely key to effective translation of findings to medicine. However, despite considerable uniformity in animal models brought about by control of genetics, there remain a number of social as wel...

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 of consciousness; time to loss of consciousness; best methods for use of CO2; and the availability of better alternatives. Th...

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 training and proficiency of personnel, and the safety and emotional needs of the personnel performing the euthanasia. This m...

Environmental enrichment provides physiological and emotional benefits to laboratory rodents. Red tinted shelters are a common enrichment found in laboratories that provide rodents with a hiding space shielded from bright light. Red tinting alters the light’s spectral make-up which reduces the amount of blue-green wavelengths while also reducing ov...

Although social housing of mice generally is preferred, mice must be individually housed in some situations. In these cases, enhanced attention to environmental enrichment is encouraged, but few studies assess the wellbeing of mice provided various enrichments. In this study, we used female ICR mice to evaluate enrichment strategies that encouraged...

Glucocorticoids (GCs) are steroid hormones secreted as the end-product of the neuroendocrine stress cascade. Both absence and elevated GC mediate neurotoxic responses, suggesting that a narrow window ranging from physiological to slightly high GC mediate protective responses. The beneficial effects of GC are attributed to the transactivation of reg...

The beneficial effect of music has been demonstrated in many species. Although commercially available music CDs intended for use with rabbits are available, these enrichments have not been critically evaluated to determine whether they reduce distress. In this study, we used an aging colony of male rabbits to evaluate how the provision of music enr...

Several investigators performing bone marrow transplantation studies have previously reported sporadic increases in mortality that were associated with pronounced swelling in the face, head and neck of mice. Over the past few years, we and others have noted an increasing number of experiments in which mice that have received total-body irradiation...

This study compared behavioral and physiologic changes in Sprague-Dawley and Brown Norway rats that were euthanizedby using a 30% volume displacement rate of CO2 in either their home cage or an induction chamber; rats euthanized in thehome cage were hypothesized to demonstrate a higher level of animal wellbeing. No significant differences were dete...

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 stress associated with rapid methods of euthanasia. However...

Introduction Glucocorticoid-induced leucine zipper is a regulatory protein that sequesters activated nuclear factor-kappa B p65. Previously, we showed that rationally designed analogs of the p65-binding domain of glucocorticoid-induced leucine zipper, referred to as glucocorticoid-induced leucine zipper analogs (GAs), inhibited amyloid β–induced me...

Spaceflight results in bone loss like that associated with osteoporosis or decreased weight-bearing (for example, high-energy trauma such as explosive injuries and automobile accidents). Thus, the unique spaceflight laboratory on the International Space Station presents the opportunity to test bone healing agents during weightlessness. We are colla...

This study was initiated as a component of a larger undertaking designed to study bone healing in microgravity aboard the International Space Station (ISS). Spaceflight experimentation introduces multiple challenges not seen in ground studies, especially with regard to physical space, limited resources, and inability to easily reproduce results. To...

Selection of an appropriate method of euthanasia involves balancing the wellbeing of the animal during the procedure with the intended use of the animal after death and the physical and psychologic safety of the observer or operator. The recommended practices for anesthesia as compared with euthanasia are very disparate, despite the fact that all c...

The 2013 AVMA Guidelines on Euthanasia recommend the use of very-low or low flow rates of 100% carbon dioxide to euthanize small rodents. Although inhalation of high concentrations of carbon dioxide are generally recognized as painful in humans, whether the use of these low-flow methods of euthanasia increase potential distress for rats is unclear....

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 body of knowledge on the subject. Potential areas for further investigation and recommendations are provide...

When evaluating the effect of husbandry and biomethodologies on the well-being of laboratory mice, it is critical to utilize measurements that allow the distinguishing of acute stress from chronic stress. One of the most common measurements of stress in laboratory animals is the corticosterone assessment. However, while this measurement provides a...

When designing a research plan for the exploration of a scientific hypothesis, it is critical to evaluate all available models, including in vitro and in vivo options, to ensure selection of the most appropriate model to yield the best information. Animal models are one tool that is used to support research, but in vitro and human models are also e...

This chapter provides an introduction to animals that are commonly used for research. It presents information on basic care topics such as biology, behavior, housing, feeding, sexing, and breeding of these animals. The chapter provides some insight into the reasons why these animals are used in research. It also gives an overview of techniques that...

Simple Summary Current recommendations for the use of CO2 as a euthanasia agent for rats require the use of gradual fill methods in order to render the animal insensible prior to their experience of pain. However, there is concern that the use of these gradual fill methods may increase the distress experienced by these animals. We evaluated social...

All animals need clean water to drink. At the authors' animal facility, drinking water for immunocompromised rodents is filtered by reverse osmosis, acidified during bottling and sterilized in an autoclave. Autoclaved water bottles can be stored in unopened autoclave bags for 7 d or in opened bags for 2 d; if not used during that time, they are emp...

Laboratory facilities use many varieties of contact bedding, including wood chips, paper products, and corncob, each with its own advantages and disadvantages. Corncob bedding, for example, is often used because of its high absorbency, ability to minimize detectable ammonia, and low cost. However, observations that mice eat the corncob lead to conc...

Current regulations emphasize that good husbandry practices allow animals to engage in species appropriate postural adjustments without touching the enclosure walls. This study evaluated the well-being of rats housed in a commercially available multilevel rat caging system, with or without access to the upper level of the caging. The evaluation met...

The ability to evaluate distress in laboratory animals is needed in order to ensure that husbandry and experimental procedures do not negatively impact animal welfare. Accurate measurement of acute stress and chronic stress, and distinguishing between stress that is harmful (distress) and stress that does no harm (eustress), can be challenging. Whe...

U.S. federal regulations and standards governing the care and use of research animals enacted in the mid- to late 1980s, while having positive effects on the welfare and quality of the animals, have resulted in dramatic increases in overall research costs. In addition to the expenses of housing and caring for animals according to the standards, est...

Lab Animal is a peer-reviewed journal offering information, ideas, methods, and materials for the animal research professional

Lab Animal is a peer-reviewed journal offering information, ideas, methods, and materials for the animal research professional

During a triinstitutional study to test whether individually ventilated caging systems impaired welfare and reproduction relative to static housing systems, varying numbers (2 to 7) of discoid-shaped, fleshy structures were found in utero of 17 postpartum female mice on study. Further investigation revealed these structures to be retained fetal mem...

In the majority of countries where there are legislative requirements pertaining to the use of animals in research, figures are quoted for minimum cage sizes or space allocation to be provided per animal. These figures are generally based on professional judgement and are in common usage. However, there is a growing trend and expectation that welfa...

Periparturient manipulation of mice is a valuable tool for modern research facilities. Although fostering and Caesarian section frequently are used to eradicate pathogens, an often overlooked use is to rescue poorly breeding strains of mice. Here we characterized the weaning success rates after fostering outbred pups of variable ages (younger than...

Dissection of living brain tissue for in vitro experiments requires the use of a rapid euthanasia method. However, the method must not subject animals to unnecessary pain and must be aesthetically acceptable to experimenters. The purposes of the current study were to assess the aesthetics of 6 euthanasia methods, measure the procedure duration, and...

Lab Animal is a peer-reviewed journal offering information, ideas, methods, and materials for the animal research professional

Imaging studies that use rodents sometimes involve intraperitoneal administration of pharmacological compounds. To facilitate such studies, the authors developed a simple and easily mastered technique for placing an intraperitoneal catheter in a conscious mouse. This technique eliminates the need to remove the animal from the scanner to administer...

Simple and noninvasive methods of assessing health and wellbeing are valuable when performing clinical evaluation of rodents used in biomedical research. Body condition score (BCS) techniques have been described for a variety of species, including mice. This method can be a sensitive objective assessment of weight loss in animal models where organ...

Accurate, rapid, and noninvasive health assessments are required to establish more appropriate endpoints in mouse cancer models where tumor size is not easily measured. We evaluated potential endpoints in mice with experimentally induced peritoneal lymphoma, an abdominal tumor model, by comparing body weight, body condition, and behavior with those...

Rodent pinworm infestations are common in modern animal facilities, and treatments to eradicate these nematodes are often costly and labor-intensive. The authors describe a method they developed to treat rodents with ivermectin using the automatic watering system available at their facility. This delivery method proved an efficacious and cost-effec...

Lab Animal is a peer-reviewed journal offering information, ideas, methods, and materials for the animal research professional

Nine of 24 ovariectomized nude mice developed ulcerative skin lesions 28 d after implantation with human breast cancer cells and slow-release estrogen pellets. Aerobic culture of samples from the skin lesions yielded Staphylococcus intermedius. By day 45 postimplantation, all mice displayed ulcerative skin lesions, and 5 mice exhibited hunched post...

When mice are used in studies where wasting and death are potential complications, practical, rapid, and noninvasive methods for assessing health status and establishing endpoints are needed. Tumor growth studies are often very challenging as the growth of the tumor may mask one of the more commonly used endpoints - loss of weight. In 1999, body co...

Preparation for the specialty board examination for the American College of Laboratory Animal Medicine (ACLAM) is an intensive process that is facilitated by geographic regions where many people studying for the exam are located in close proximity. However, many people work at institutions that are distant from these 'study centers'. Approximately...

This chapter describes the most important anatomical and physiological features of the laboratory rat. The body of a normal, healthy Norway rat is long and slender. The tail is hairless and may be as long as 85% of the total body. The tail is proportionately longer in females than in males. Growth rates and maturation times for rats varies by strai...

Steps were taken to eradicate endemic mouse coronavirus from a colony that was part of a behavioral project characterizing the genetics of alcohol sensitivity. This behavioral study was conducted to determine whether changing the uterine or rearing environment (as is integral to common rederivation methods) would have a significant effect on the ex...

Two replicate lines of mice, selected for hyperactivity and hypoactivity after ethanol administration, had been enzootically infected with mouse hepatitis virus (MHV) for over a decade. A cessation of breeding program (also known as a "burnout") was implemented to eradicate the virus and was successful in only one of the four lines. Subsequent inve...

Infections with mouse coronavirus (also known as mouse hepatitis virus, MHV) are common and prompt concern because the adverse research effects of infection have been well documented. The animal facility we describe had contained an enzootic infection of mouse coronavirus for more than a decade. Eradication of the virus had been tried with limited...

Infections with mouse coronavirus (also known as mouse hepatitis virus, MHV) are common and prompt concern because the adverse research effects of infection have been well documented. The animal facility we describe had contained an enzootic infection of mouse coronavirus for more than a decade. Eradication of the virus had been tried with limited...

Lab Animal is a peer-reviewed journal offering information, ideas, methods, and materials for the animal research professional

The ability to manipulate mouse pre-implantation embryos in vitro has become a valuable tool in many scientific disciplines. However, fewer embryos maintain viability following in vitro manipulation compared with embryos in vivo. It has been suggested that use of dynamic medium environments may improve viability by simulating in utero environment....