Care and Well-Being of Laboratory Animals

A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Animal Welfare".

Deadline for manuscript submissions: 25 January 2025 | Viewed by 19566

Special Issue Editor


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Guest Editor
1. Department of Laboratory Animal Science and Animal Welfare, Justus-Liebig University, Giessen, Germany
2. 3R Centre JLU Giessen, Interdisciplinary Centre for 3Rs in Animal Research (ICAR3R), Giessen, Germany
Interests: stereotypies in laboratory rodents; assessment of suffering; 3R-Education; culture of care

Special Issue Information

Dear Colleagues, 

Animals have been attributed an intrinsic value. Ethological studies allow us to better understand the complexity of animals' sensory perceptions and suffering capacities. Thus, enormous responsibilities arise in the use and husbandry of experimental animals as sentient beings. Comprehensive measures are indispensable to continuously improve care and to provide the best possible opportunities to maintain animal welfare.

Care work describes the unpaid and paid (re-)productive activities of mindfulness and solicitude, reflecting both caring and self-care. The concept of care, thus, refers to the everyday, recurring nursing and supervision of animals by animal caretakers. In addition, however, all stakeholders are involved in a far more comprehensive way. Thus, the concept of care also extends to the knowledge, organization and responsibility required in this process.

The maintenance of well-being repeatedly poses challenges for all those involved, as laboratory animal husbandry predominantly occurs in a highly anthropogenic husbandry environment. It seems necessary to change the perspective in terms of the animals' perception to meet their needs and demands.

This Special Issue highlights the multifaceted aspects of care and well-being of laboratory animals from different professional perspectives, addressing ethical views as well as the most recent insights from practice for practice.

Prof. Dr. Stephanie Krämer
Guest Editor

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Keywords

  • animal husbandry
  • animal welfare
  • refinement
  • enrichment
  • animal ethics
  • concept of care

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Published Papers (10 papers)

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Research

Jump to: Review, Other

13 pages, 1707 KiB  
Article
Think Beyond the Room: Measuring Relative Humidity in the Home Cage and Its Impact on Reproduction in Laboratory Mice, Mus musculus
by Amanda J. Barabas, Ronald A. Conlon and Craig A. Hodges
Animals 2024, 14(22), 3164; https://doi.org/10.3390/ani14223164 - 5 Nov 2024
Viewed by 824
Abstract
Relative humidity (RH) is measured in vivaria with a broad range to accommodate seasonal fluctuations. It is assumed that measurements in the room (macroenvironment) reflect those in the cage (microenvironment). However, there is limited data comparing RH in the macroenvironment to the microenvironment [...] Read more.
Relative humidity (RH) is measured in vivaria with a broad range to accommodate seasonal fluctuations. It is assumed that measurements in the room (macroenvironment) reflect those in the cage (microenvironment). However, there is limited data comparing RH in the macroenvironment to the microenvironment and how the mice may be affected by variations in RH that fall within husbandry recommendations. This study aimed to compare RH in the macroenvironment to that of the microenvironment in various group sizes of laboratory mice; and examine how variation in microenvironmental RH impacts pup survival. Temperature and RH were measured using a temperature/humidity data logger attached to a solid top cage lid. The lid was rotated across N = 48 breeding trios and N = 33 same sex cages on a C57BL/6J background. Further, once a week, a single breeding trio was selected (N = 23) to compare RH readings to weekly rates of pup loss in a larger breeding colony. Across all cages, RH was higher in the microenvironment than the macroenvironment. RH was universally higher in the summer than in the winter, and increased with group size. For breeding cages, as microenvironmental RH increased, the proportion of pups lost each week decreased in a linear relationship. No threshold of decreased mortality could be identified. These data highlight RH as a potential extrinsic factor. While these patterns are correlational, they warrant further research focused on the causative role of RH on mouse welfare. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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15 pages, 7401 KiB  
Article
Longitudinal Study of Changes in Ammonia, Carbon Dioxide, Humidity and Temperature in Individually Ventilated Cages Housing Female and Male C57BL/6N Mice during Consecutive Cycles of Weekly and Bi-Weekly Cage Changes
by Martina Andersson, Karin Pernold, Niklas Lilja, Rafael Frias-Beneyto and Brun Ulfhake
Animals 2024, 14(18), 2735; https://doi.org/10.3390/ani14182735 - 21 Sep 2024
Viewed by 987
Abstract
Housing conditions are essential for ensuring animal welfare and high-quality research outcomes. In this study, we continuously monitored air quality—specifically ammonia, carbon dioxide, relative humidity, and temperature—in Individually Ventilated Cages (IVCs) housing five female or male C57BL/6N mice. The cages were cleaned either [...] Read more.
Housing conditions are essential for ensuring animal welfare and high-quality research outcomes. In this study, we continuously monitored air quality—specifically ammonia, carbon dioxide, relative humidity, and temperature—in Individually Ventilated Cages (IVCs) housing five female or male C57BL/6N mice. The cages were cleaned either weekly or bi-weekly, and the data were collected as the mice aged from 100 to 348 days. The survival rate remained above 96%, with body weight increasing by 35–52% during the study period. The ammonia levels rose throughout the cleaning cycle, but averaged below 25 ppm. However, in the older, heavier mice with bi-weekly cage cleaning, the ammonia levels reached between 25 and 75 ppm, particularly in the males. While circadian rhythms influenced the ammonia concentration only to a small extent, the carbon dioxide levels varied between 800 and 3000 ppm, increasing by 30–50% at night and by 1000 ppm with body weight. Humidity also correlated primarily with the circadian rhythms (10% higher at night) and, to a lesser extent, with body weight, reaching ≥70% in the middle-aged mice. The temperature variations remained minimal, within a 1 °C range. We conclude that air quality assessments in IVCs should be conducted during animals’ active periods, and both housing density and biomass must be considered to optimise welfare. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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9 pages, 2523 KiB  
Article
Optimized Depilation Method and Comparative Analysis of Hair Growth Cycle in Mouse Strains
by Joana Magalhaes, Sofia Lamas, Carlos Portinha and Elsa Logarinho
Animals 2024, 14(14), 2131; https://doi.org/10.3390/ani14142131 - 22 Jul 2024
Viewed by 1275
Abstract
In mice, hair growth follows a mosaic or wavy patterning. Therefore, synchronization of the hair growth cycle is required to adequately evaluate any trichogenic interventions pre-clinically. Depilation is the established method for synchronizing the growth phase of mouse hair follicles. When attempting to [...] Read more.
In mice, hair growth follows a mosaic or wavy patterning. Therefore, synchronization of the hair growth cycle is required to adequately evaluate any trichogenic interventions pre-clinically. Depilation is the established method for synchronizing the growth phase of mouse hair follicles. When attempting to reproduce procedures reported in the literature, C57BL/6J mice developed severe wounds. This led us not only to optimize the procedure, but also to test the procedure in other strains, namely Sv129 and the F1 generation from C57BL/6J crossed with Sv129 (B6129F1 mixed background), for which the hair growth cycle has not been ascertained yet. Here, we describe an optimized depilation procedure, using cold wax and an extra step to protect the animal skin that minimizes injury, improving experimental conditions and animal welfare in all strains. Moreover, our results show that, although hair cycle kinetics are similar in all the analyzed strains, Sv129 and B6129F1 skins are morphologically different from C57BL/6J skin, presenting an increased number and size of hair follicles in anagen, consistent to the higher hair density observed macroscopically. Altogether, the results disclose an optimized mouse depilation method that excludes the detrimental and confounding effects of skin injury in hair growth studies and reveals the hair cycle features of other mouse strains, supporting their use in hair growth pre-clinical studies. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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12 pages, 280 KiB  
Article
Humane Endpoints in Swiss Webster Mice Infected with Toxoplasma gondii RH Strain
by Igor Falco Arruda, Maria Regina Reis Amendoeira, Thamires Francisco Bonifácio, Clarissa Nascimento da Silveira Raso, Hyago da Silva Medeiros Elidio, Jhônata Willy Rocha Coelho, Luiz Cesar Cavalcanti Pereira da Silva and Isabele Barbieri dos Santos
Animals 2024, 14(9), 1326; https://doi.org/10.3390/ani14091326 - 29 Apr 2024
Cited by 1 | Viewed by 1056
Abstract
The highly virulent Toxoplasma gondii RH strain is maintained through successive passages in mice, but there is still a lack of studies that refine these procedures from a 3Rs perspective, where humanitarian ideals aim to minimize the stress, pain, or suffering of the [...] Read more.
The highly virulent Toxoplasma gondii RH strain is maintained through successive passages in mice, but there is still a lack of studies that refine these procedures from a 3Rs perspective, where humanitarian ideals aim to minimize the stress, pain, or suffering of the animals used in the research without the loss of results. The aim of this study was to establish humane endpoints in Swiss Webster mice inoculated with the T. gondii RH strain. A total of 52 mice were infected with 5 × 106 tachyzoites/mL and monitored for periods of up to 5 days. The parameters body weight; hair condition; higher than normal body temperature; hypothermia; respiratory function; pain; soft stools or diarrhea; bloody diarrhea; tense, nervous, or in distress during handling; and ascites were recorded daily in score tables. The results showed that prominent piloerection, respiratory function, pain parameters, and ascites are important clinical signs to be used as a cut-off point for implementing euthanasia. The application of this refinement method helped to avoid animal suffering and pain without compromising the number of parasites recovered. We therefore suggest adopting these parameters in research protocols that require the maintenance of the T. gondii RH strain in murine models to avoid and reduce animal suffering. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
16 pages, 10586 KiB  
Article
What Can Laboratory Animal Facility Managers Do to Improve the Welfare of Laboratory Animals and Laboratory Animal Facility Staff? A German Perspective
by Birte von der Beck, Andreas Wissmann, Rene H. Tolba, Philip Dammann and Gero Hilken
Animals 2024, 14(7), 1136; https://doi.org/10.3390/ani14071136 - 8 Apr 2024
Cited by 1 | Viewed by 2524
Abstract
Laboratory animal facility managers must ensure that animal experiments can be carried out under optimal scientific conditions, that all legal requirements are met, and that animal welfare is maximized. Animal experimentation is stressful not only for the animals involved but also for the [...] Read more.
Laboratory animal facility managers must ensure that animal experiments can be carried out under optimal scientific conditions, that all legal requirements are met, and that animal welfare is maximized. Animal experimentation is stressful not only for the animals involved but also for the people who maintain these animals or carry out the experiments. Many of those involved find themselves in a constant conflict between scientific necessity, care, and harm. Under the term Culture of Care, procedures have been developed to reduce the burden of animal experimentation on the animals and the staff involved. The focus here is on what laboratory animal facility managers can do to improve the welfare of laboratory animals and the people working with them. Exemplary measures are the improvement of the housing conditions of laboratory animals, the introduction of uniform handling measures, clear and transparent structures via a quality management system, implementation of a no-blame culture of error (e.g., via Critical Incident Reporting System in Laboratory Animal Science [CIRS-LAS]), and open and respectful communication with all parties involved in animal experimentation, including the public and representatives of the authorities (public webpage, open house policy). The 6 Rs must be considered at all times: replacement, reduction, refinement, respect, responsibility, and reproducibility. We are writing this article from the perspective of laboratory animal facility managers in Germany. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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15 pages, 2290 KiB  
Article
Potential Food Inclination of Crab-Eating Macaques in Laboratory Environments: Enhancing Positive Reinforcement Training and Health Optimization
by Ji Woon Kim, Yoon Beom Lee, Yeon Su Hong, Hoesu Jung and Gwang-Hoon Lee
Animals 2024, 14(7), 1123; https://doi.org/10.3390/ani14071123 - 7 Apr 2024
Viewed by 1533
Abstract
Positive reinforcement and training for health optimization are pivotal for successful studies with monkeys. Potential food inclination is important for studies on crab-eating macaques in laboratory environments, but evaluations remain scarce. We explored crab-eating macaques’ potential food inclination to establish a reward system [...] Read more.
Positive reinforcement and training for health optimization are pivotal for successful studies with monkeys. Potential food inclination is important for studies on crab-eating macaques in laboratory environments, but evaluations remain scarce. We explored crab-eating macaques’ potential food inclination to establish a reward system for future behavioral assessments. Twelve male and three female monkeys underwent a food inclination assessment in which they were offered four food categories—fruits, vegetables, proteins, and nuts. The monkeys exhibited a higher inclination for plant-based foods, particularly fruits and vegetables, over animal-based proteins like chicken and tuna (p < 0.0001), with a notable inclination for nuts (eaten/provided = 100%). Additionally, the consistency of potential food inclination after repeated offerings was investigated, revealing a time-dependent increase in inclination for protein items. Food consumption ratios correlated positively with caloric intake (r = 0.59, p = 0.02), implying that individuals with a regular high caloric intake and increased body weight are more likely to accept food during positive reinforcement training. Our findings suggest fruits, vegetables, protein-rich foods, and nuts can help with health optimization. However, animal-based protein-rich foods initially had a low preference, which may increase over time. Our study can provide guidelines for positive reinforcement training and health optimization. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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16 pages, 811 KiB  
Article
Rat Grimace Scale as a Method to Evaluate Animal Welfare, Nociception, and Quality of the Euthanasia Method of Wistar Rats
by Adriana Domínguez-Oliva, Adriana Olmos-Hernández, Ismael Hernández-Ávalos, Hugo Lecona-Butrón, Patricia Mora-Medina and Daniel Mota-Rojas
Animals 2023, 13(20), 3161; https://doi.org/10.3390/ani13203161 - 10 Oct 2023
Cited by 5 | Viewed by 3150
Abstract
Refinement of experimental procedures in animal research has the objective of preventing and minimizing pain/distress in animals, including the euthanasia period. This study aimed to evaluate pain associated with six methods of euthanasia in Wistar rats (injectable, inhalational, and physical), by applying the [...] Read more.
Refinement of experimental procedures in animal research has the objective of preventing and minimizing pain/distress in animals, including the euthanasia period. This study aimed to evaluate pain associated with six methods of euthanasia in Wistar rats (injectable, inhalational, and physical), by applying the Rat Grimace Scale (RGS), comparing the scores, and determining the method with the highest score that might indicate pain for laboratory rodents. Sixty adult male and female Wistar rats were used and assigned to six treatments: pentobarbital, CO2, decapitation, isoflurane, ketamine + xylazine, and ketamine + CO2. Video recording to assess the RGS scores was performed in four events: basal: 24 h before the procedure; Ti1: three minutes before the procedure; Ti2: during the application of the euthanasia method; and Ti3: immediately after the application until LORR. The main findings of this study showed that, during Ti2, decapitation and ketamine + xylazine had the highest scores (0.6 ± 0.26 and 0.6 ± 0.16, respectively) (p < 0.0001), while at Ti3, CO2 (0.9 ± 0.18) and isoflurane (1.2 ± 0.20) recorded the highest scores (p < 0.0001). According to the present results, decapitation and ketamine + xylazine elicited short-term acute pain, possibly due to tissue damage caused by both methods (injection and guillotine). In contrast, isoflurane’s RGS scores recorded during Ti3 might be associated with nociception/pain due to the pungency of the drug or to the pharmacological muscle relaxant effect of isoflurane. Further research is needed to establish a comprehensive study of pain during euthanasia, where RGS could be used minding the limitations that anesthetics might have on facial expression. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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21 pages, 1474 KiB  
Article
Reduction in Cold Stress in an Innovative Metabolic Cage Housing System Increases Animal Welfare in Laboratory Mice
by Laura Wittek, Chadi Touma, Tina Nitezki, Thomas Laeger, Stephanie Krämer and Jens Raila
Animals 2023, 13(18), 2866; https://doi.org/10.3390/ani13182866 - 9 Sep 2023
Cited by 1 | Viewed by 2332
Abstract
Housing in metabolic cages can induce a pronounced stress response. Metabolic cage systems imply housing mice on metal wire mesh for the collection of urine and feces in addition to monitoring food and water intake. Moreover, mice are single-housed, and no nesting, bedding, [...] Read more.
Housing in metabolic cages can induce a pronounced stress response. Metabolic cage systems imply housing mice on metal wire mesh for the collection of urine and feces in addition to monitoring food and water intake. Moreover, mice are single-housed, and no nesting, bedding, or enrichment material is provided, which is often argued to have a not negligible impact on animal welfare due to cold stress. We therefore attempted to reduce stress during metabolic cage housing for mice by comparing an innovative metabolic cage (IMC) with a commercially available metabolic cage from Tecniplast GmbH (TMC) and a control cage. Substantial refinement measures were incorporated into the IMC cage design. In the frame of a multifactorial approach for severity assessment, parameters such as body weight, body composition, food intake, cage and body surface temperature (thermal imaging), mRNA expression of uncoupling protein 1 (Ucp1) in brown adipose tissue (BAT), fur score, and fecal corticosterone metabolites (CMs) were included. Female and male C57BL/6J mice were single-housed for 24 h in either conventional Macrolon cages (control), IMC, or TMC for two sessions. Body weight decreased less in the IMC (females—1st restraint: −6.94%; 2nd restraint: −6.89%; males—1st restraint: −8.08%; 2nd restraint: −5.82%) compared to the TMC (females—1st restraint: −13.2%; 2nd restraint: −15.0%; males—1st restraint: −13.1%; 2nd restraint: −14.9%) and the IMC possessed a higher cage temperature (females—1st restraint: 23.7 °C; 2nd restraint: 23.5 °C; males—1st restraint: 23.3 °C; 2nd restraint: 23.5 °C) compared with the TMC (females—1st restraint: 22.4 °C; 2nd restraint: 22.5 °C; males—1st restraint: 22.6 °C; 2nd restraint: 22.4 °C). The concentration of fecal corticosterone metabolites in the TMC (females—1st restraint: 1376 ng/g dry weight (DW); 2nd restraint: 2098 ng/g DW; males—1st restraint: 1030 ng/g DW; 2nd restraint: 1163 ng/g DW) was higher compared to control cage housing (females—1st restraint: 640 ng/g DW; 2nd restraint: 941 ng/g DW; males—1st restraint: 504 ng/g DW; 2nd restraint: 537 ng/g DW). Our results show the stress potential induced by metabolic cage restraint that is markedly influenced by the lower housing temperature. The IMC represents a first attempt to target cold stress reduction during metabolic cage application thereby producing more animal welfare friendlydata. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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Review

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19 pages, 544 KiB  
Review
Research Animal Behavioral Management Programs for the 21st Century
by Patricia V. Turner and Kathryn Bayne
Animals 2023, 13(12), 1919; https://doi.org/10.3390/ani13121919 - 8 Jun 2023
Cited by 3 | Viewed by 3033
Abstract
Behavioral management programs have been developed commonly for research dogs and primates but rarely has program consideration been expanded to include all research species worked with. This is necessary to reduce animal stress and promote natural behaviors, which can promote good animal welfare [...] Read more.
Behavioral management programs have been developed commonly for research dogs and primates but rarely has program consideration been expanded to include all research species worked with. This is necessary to reduce animal stress and promote natural behaviors, which can promote good animal welfare and result in more robust and reproducible scientific data. We describe the evolution of consideration for research animal needs and define an umbrella-based model of research animal behavioral management programs, which may be used for all research species. In addition to developing a more comprehensive program, we emphasize the need for regular welfare assessments to determine whether the program is working cohesively and whether any aspects require modification. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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Other

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21 pages, 8890 KiB  
Case Report
Added Value of Sensor-Based Behavioural Monitoring in an Infectious Disease Study with Sheep Infected with Toxoplasma gondii
by Harmen P. Doekes, Ronald Petie, Rineke de Jong, Ines Adriaens, Henk J. Wisselink and Norbert Stockhofe-Zurwieden
Animals 2024, 14(13), 1908; https://doi.org/10.3390/ani14131908 - 27 Jun 2024
Viewed by 1454
Abstract
Sensor technologies are increasingly used to monitor laboratory animal behaviour. The aim of this study was to investigate the added value of using accelerometers and video to monitor the activity and drinking behaviour of three rams from 5 days before to 22 days [...] Read more.
Sensor technologies are increasingly used to monitor laboratory animal behaviour. The aim of this study was to investigate the added value of using accelerometers and video to monitor the activity and drinking behaviour of three rams from 5 days before to 22 days after inoculation with Toxoplasma gondii. We computed the activity from accelerometer data as the vectorial dynamic body acceleration (VDBA). In addition, we assessed individual drinking behaviour from video, using frame differencing above the drinker to identify drinking bouts, and Aruco markers for individual identification. Four days after inoculation, rams developed fever and activity decreased. The daytime VDBA from days 4 to 10 was 60–80% of that before inoculation. Animal caretakers scored rams as lethargic on days 5 and 6 and, for one ram, also on the morning of day 7. Video analysis showed that each ram decreased its number of visits to the drinker, as well as its time spent at the drinker, by up to 50%. The fever and corresponding sickness behaviours lasted until day 10. Overall, while we recognize the limited conclusiveness due to the small number of animals, the sensor technologies provided continuous, individual, detailed, and objective data and offered additional insights as compared to routine observations. We recommend the wider implementation of such technologies in animal disease trials to refine experiments and guarantee the quality of experimental results. Full article
(This article belongs to the Special Issue Care and Well-Being of Laboratory Animals)
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