Animal Welfare Information Center
United States Department of Agriculture
National Agricultural Library
United States Department of Agriculture
National Agricultural Library
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Animal Welfare Information Center United States Department of Agriculture National Agricultural Library |
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Information Resources on the Care and Welfare of Rodents |
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Ago, A., T. Gonda, M. Takechi, T. Takeuchi, and K. Kawakami (2002). Preferences for paper bedding material of the laboratory mice. Experimental Animals (Tokyo) 51(2): 157-61. ISSN: 1341-1357.
Abstract: In order to identify indicators of the preferences for bedding materials, the paper bedding material preferences of laboratory mice were investigated in the present study. Four cages, each containing a different structure of paper bedding material were connected to allow free access to each cage. The preferences for paper bedding materials of laboratory mice were judged by the differences in the length of stay and sleep in each cage. The mice preferred the bedding material that allowed them to easily hide and build nests and was soft. We conclude that the comfort and well-being of laboratory mice can be increased through the appropriate selection of bedding material.
Descriptors: mice, animal husbandry, bedding material, paper, preference, comfort, well-being.
Andrade, C.S. and F.S. Guimaraes (2003). Anxiolytic-like effect of group housing on stress-induced behavior in rats. Depression and Anxiety 18(3): 149-52. ISSN: 1091-4269.
Descriptors: anti anxiety agents pharmacology, behavior, animal drug effects, diazepam pharmacology, social behavior, stress psychology, anti anxiety agents administration and dosage, diazepam administration and dosage, rats, Wistar rats.
Anonymous (2000). Draft comparison of space allowance/stocking density and the EU draft recommendations. Animal Technology 51(2): 101-109. ISSN: 0264-4754.
NAL Call Number: QL55.I5
Descriptors: laboratory animals, space requirements, floor space, mice, rats, hamsters, gerbils, guinea pigs, rabbits, dogs, cats, cages, cage size, group size, group housing.
Arakawa, H. (2005). Age dependent effects of space limitation and social tension on open-field behavior in male rats. Physiology and Behavior 84(3): 429-436. ISSN: 0031-9384.
Abstract: Cage stocking density can be manipulated by changing in cage size and group size in the cage. The effects of these two factors were investigated in three developmental stages in male rats: juvenile, post-pubertal, and adult. An open-field test was conducted to measure exploratory behavior which was influenced by levels of activity, anxiety, and exploration. When the cage size was decreased, juvenile rats displayed decreased locomotion and lower propensity for exploration, whereas such changes were not evident in post-pubertal rats. When the group size was increased, adult rats exhibited higher locomotion. However, these factors did not affect risk assessment behavior of rats in these developmental stages. Thus, it appears that the effect of stocking density differs depending on the developmental stage of the animal: Juvenile rats increased anxiety following limiting space, whereas adult rats increased activity following increase in social tension.
Descriptors: male rats, space limitation, effects, age, social tension, density, behavior, group size.
Baer, L.A., B.J. Corbin, M.F. Vasques, and R.E. Grindeland (1997). Effects of the use of filtered microisolator tops on cage microenvironment and growth rate of mice. Laboratory Animal Science 47(3): 327-329. ISSN: 0023-6764.
NAL Call Number: 410.9 P94
Descriptors: microenvironments, filters, cages, growth rate, body weight, mice.
Barrett, D., C. Keenan, J. Kimball, L. Smith, and W. Powers (1996). The effect of ad libitum feeding, group housing, and moderate dietary restriction on longevity, body weight gain, and clinical pathology parameters of Sprague-Dawley (SD) rats. Toxicologic Pathology 24(6): 788. ISSN: 0192-6233.
Descriptors: rats, feeding, group housing, adlibitum, dietary restriction, effect, weight gain, pathology.
Notes: Meeting Information: XV International Symposium of the Society of Toxicologic Pathologists, June 9-13, 1996, St. Louis, Missouri, USA.
Bartolomucci, A., P. Palanza, and S. Parmigiani (2002). Group housed mice: are they really stressed? Ethology, Ecology and Evolution 14(4): 341-350. ISSN: 0394-9370.
Descriptors: mice, group housing, stress, adrenal glands, behavior, male, group behavior, group interaction, social status, subordinate.
Bartolomucci, A., P. Palanza, P. Sacerdote, G. Ceresini, A. Chirieleison, A.E. Panerai, and S. Parmigiani (2003). Individual housing induces altered immuno-endocrine responses to psychological stress in male mice. Psychoneuroendocrinology 28(4): 540-58. ISSN: 0306-4530.
Abstract: Social isolation and lack of social support have deleterious effects on health, thus being regarded as one of the most relevant causes of diseases in human and other mammalian species. However, only few are the studies aimed at evaluating the psychoneuroimmunological functions of individually housed subjects. The present study was designed to understand how the behavior and the physiology of male house mice might be affected by individual housing. We first analyzed whether individual housing of different duration (1-42 days) would result in immuno-endocrine dysfunction (experiment 1). Then we investigated whether housing conditions would affect the reaction to an acute mild psychological stress (experiments 2 and 3). There were three main findings: first, individually housing mice for increasing time periods did not induce any major immuno-endocrine effects compared to a stable sibling group housing. Therefore, prolonged isolation does not seem to dramatically impair mice immuno-endocrine functions. Second, when exposed to a mild acute stress, i.e. forced exposure to a novel environment, isolated mice showed higher basal corticosterone and lower type 1 (IL-2) and type 2 (IL-4) cytokines as well as splenocytes proliferation compared to group housed male mice. Finally, when faced with a free choice between a novel environment and their home cage, individually housed mice showed reduced neophobic responses resulting in increased exploration of the novel environment, thus suggesting a low anxiety profile. Altogether, our findings suggest that individual housing in itself does not change immunocompetence and corticosterone level, but does affect reactivity to a stressor. In fact, individually housed mice showed high behavioral arousal, as well as altered immuno-endocrine parameters, when challenged with mild psychological novelty-stress.
Descriptors: neuroimmunomodulation physiology, social isolation psychology, psychological immunology, stress, psychological psychology, adaptation, physiological physiology, body weight physiology, corticosterone blood, dominance subordination, endocrine system physiology, housing, animal, interferon type II blood, interleukin 10 blood, mice, social environment.
Baumans, V., F. Schlingmann, M. Vonck, and H.A. Van Lith (2002). Individually ventilated cages: beneficial for mice and men? Contemporary Topics in Laboratory Animal Science 41(1): 13-9. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Abstract: Housing systems are an important element in the well-being of laboratory animals and, consequently, influence the outcomes of animal experiments. Individually ventilated cage (IVC) systems were developed to maintain low ammonia and CO(2) concentrations, to support a low relative humidity, and to reduce spread of infective agents and allergenic contaminants. However, the increased intracage ventilation rates (25 to 100 air changes/h) in these systems have animal welfare implications. In four preference studies involving a total of 36 pairs of female BALB/c mice and three different types of IVC racks, we tested the preference/avoidance of mice for the intracage ventilation rate, cage size, location of air supply, and presence of nesting material in a two-cage system. In this system, the two cages were connected by a passage with a swing-door to allow mice to move freely between the cages. We found that the mice avoided high intracage ventilation rates but that providing nesting material could counteract this avoidance. In addition, the mice preferred larger cages and an air supply in the cover. We conclude that the location of the air supply in the cage, cage size, ventilation rate and the presence of nesting material in IVC systems influence the well-being of the animals.
Descriptors: mice, animal husbandry, methods, environment, housing, ventilation methods, animal welfare.
Bazille, P.G., S.D. Walden, B.L. Koniar, and R. Gunther (2001). Commercial cotton nesting material as a predisposing factor for conjunctivitis in athymic nude mice. Lab Animal 30(5): 40-2. ISSN: 0093-7355.
NAL Call Number: QL55.A1L33
Abstract: Environmental enrichment for rodents is beneficial, but compatibility between the enrichment device and the rodent strain must also be considered. The authors present a case in which the use of a specific form of environmental enrichment--cotton bedding material--proved detrimental to the health of athymic nude mice, increasing the likelihood of conjunctivitis.
Descriptors: nude mice, animal husbandry, nesting material, cotton, conjunctivitis, adverse effects, predisposing factor, pathology.
Bell, L. (2003). Concerns about mouse housing system. Contemporary Topics in Laboratory Animal Science 42(1): 7. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: laboratory animals, housing, mice, concerns.
Benefiel, A.C. and W.T. Greenough (1998). Effects of experience and environment on the developing and mature brain: implications for laboratory animal housing. ILAR Journal 39(1): 5-11. ISSN: 1084-2020.
NAL Call Number: QL55.A1I43
Descriptors: laboratory mammals, postnatal development, stimuli, brain, nerve cells, learning, rats, pigs, environment, enrichment, adrenal glands, weight, stress response, animal housing, abnormal behavior, animal welfare, astrocytes.
Blum, C.A., A.K. Wilson, and M.H. Bhattacharyya (1999). A nest box to facilitate excreta collection from mouse dams through pregnancy, parturition, and lactation. Contemporary Topics in Laboratory Animal Science 38(3): 71-77. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: mice, dams mothers, metabolism cages, nests, feces collection, maternal behavior, defecation, urination, lactation, mutants, cadmium, pregnancy, body weight.
Bochnowicz, S., R.R. Osborn, D.W.P. Hay, and D.C. Underwood (1997). Hypoxia-induced pulmonary hypertension in an optimized environment for the guineapig. Laboratory Animals 31(4): 347-356. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Prolonged exposure to hypoxia elicits a variety of time-related morphologic and physiologic changes in the pulmonary vasculature of mammals, including humans. The study of hypoxia-induced changes in rodents generally requires a prolonged exposure to 9% oxygen for a minimum of 10 days in an airtight chamber, which has only been generally described in the literature as large (200-400 l), sealed acrylic chambers. To assist in the search for better therapies for diseases associated with chronic hypoxia using animal models, we have custom-built an airtight chamber for hypoxic exposure of rodents, and characterized the effect of chronic hypoxia on functional and morphologic changes in the pulmonary vasculature of the guineapig using this system. This chamber has been designed to alleviate any unnecessary stress related to food or water intake, cleanliness and excess illumination to the animals during the hypoxic-exposure period. Chronic exposure of the guineapig to hypoxia (0-21 days) produced time-related physiologic, morphologic, and haematologic changes. For example, after 10 days in hypoxia (9% oxygen), pulmonary artery pressure was significantly increased from 13 +/- 1 mmHg in normoxic controls (day 0, n=6) to 26 +/- 0 mmHg (day 10, n=4, P<0.01). Right ventricular hypertrophy in hypoxic animals, presented as a ratio of right ventricle free wall weight to body weight, showed a significant increase from 0.054 +/- 0.004 (day 0) to 0.069 + 0.004 on day 10 (P < 0.05 ), while age-matched normoxic animals showed no changes in right ventricular weight (day 0=0.059; day 10=0.058; P>0.05). Red blood cell count significantly increased over the same time period, from 5.9 +. 0.1 (day 0) to 6.4 +/- 0.1 (day 10, P < 0.05), as did haematocrit, 48 +/- 0.7 (day 0) to 61 +/- 0.9 (day 10, P < 0.05), and haemoglobin, 16 +/- 0.2 (day 0) to 20 +/- 0.1 (day 10, P<0.05). It is concluded that considerations for the well-being of the test animals (i.e. continuous water, ample food supplies, burrow-like hiding places, sanitation and protection from excess illumination) can easily be incorporated into a hypoxic chamber. The purpose of the present study was to explore modifications that may provide the animal with an optimized environment which will reduce anxiety and stress, as seen in their behaviour when inside the chambers, and to thoroughly characterize the morphologic and physiologic changes associated with chronic hypoxia which develop in a consistent time-related manner.
Descriptors: guinea pigs, hypoxia, hypertension, lungs, erythrocyte count, hematocrit, platelet count, animal housing, body weight, stress factors, animal welfare.
Borrello, P., E. D'Amore, A. Di Virgilio, G. Panzini, M. Valeri, and R.N. Lorenzini (1998). The use of AGI as a method to measure microbial contamination in the cage microenvironment. Animal Technology 49(2): 81-85. ISSN: 0264-4754.
NAL Call Number: QL55.I5
Abstract: The microenvironmental investigation is highly important to understand the profound relationship between laboratory animals and their environment. Until now there has been no dynamic method for air sampling inside cages that house laboratory animals. As our institutional responsibilities include air quality control in the animal facilities, a new sampling method was set up, through the use of the liquid impinger AGI 30, in order to evaluate the microbial count inside the laboratory animal cages. Temperature and the relative humidity were also monitored both inside the cages and in the animal facility room and the relationship between these two parameters and the microorganisms recovery were analysed.
Descriptors: laboratory animals, air quality, sampling, artificial ventilation, air flow, environmental temperature, relative humidity, plate count, microbial contamination, rats.
Boulukos, K.E. and P. Pognonec (2001). MICE, a program to track and monitor animals in animal facilities. BMC Genetics 2(4) ISSN: 1471-2156.
Descriptors: computerized, tracking, databases, mice, monitoring, animal facilities.
Bowen, H., T.D. Mitchell, and R.B.S. Harris (2003). Method of leptin dosing, strain, and group housing influence leptin sensitivity in high-fat-fed weanling mice. American Journal of Physiology 284(1, Part 2): R87-R100. ISSN: 0002-9513.
NAL Call Number: 447.8 Am3
Descriptors: high fat diet, food intake, energy intake, body weight, body composition, obesity, injection, group housing, strain differences, mice, weanlings, animal models, leptin resistance, juvenile diet induced obesity.
Brotto, L.A., B.B. Gorzalka, and L.A. Hanson (1998). Effects of housing conditions and 5-HT2A activation on male rat sexual behavior. Physiology and Behavior 63(4): 475-9. ISSN: 0031-9384.
Abstract: Adult male rats were housed individually or in groups for a period of 39 days. In Experiment 1, the effects of housing conditions on sexual behavior and concurrent spontaneous "wet dog shaking" (WDS) were investigated. Individual housing significantly impaired male sexual behavior and resulted in a trend toward increased WDS. In Experiment 2, the effects of housing conditions were examined following administration of the serotonergic type 2A (5-HT2A) agonist DOI. Individual housing significantly increased DOI-induced WDS. The implications of these findings are discussed in the context of stress-induced corticosterone secretion and the possible regulatory effect on 5-HT2A receptors.
Descriptors: male rats, sexual behavior, housing conditions, effects, serotonin physiology, social environment, Wistar rats, social isolation psychology.
Buda, L.A. and R.L. Corwin (2004). Rats housed in large cages gain significantly more weight than rats housed in small cages. FASEB Journal 18: 4-5 (Abst. 109.6). ISSN: 0892-6638.
Online: http://www.fasebj.org/
Descriptors: rats, housing, large cages, small cages, behavior, enrichment, food intake, body weight, social conspecifics.
Notes: Meeting Information: FASEB Meeting on Experimental Biology: Translating the Genome, April 17-21, 2004, Washington, D.C., USA.
Buddaraju, A.K.V. and R.W. Van Dyke (2003). Effect of animal bedding on rat liver endosome acidification. Comparative Medicine 53( 6): 616-621. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: Animal beddings, such as pine products, and environmental factors are known to induce liver drug-metabolizing cytochrome P450 enzymes. We observed that a change to pine-based rat bedding altered baseline and cAMP-stimulated rates of acidification in rat liver endosomes, apparently by decreasing ATP-dependent proton transport in the presence and absence of chloride. Although cAMP altered phosphorylation of protein kinase B and extracellular signal-regulated kinases 1 and 2 (ERK 1,2) and p38 mitogen-activated protein kinases, changes in housing conditions did not affect baseline or cAMP-stimulated values of these or other selected signaling molecules. We conclude that compounds in rat bedding may alter not only drug metabolism, but also aspects of endocytosis.
Descriptors: rats, litter bedding, wood chips, corn cobs, endosome acidification, effect, drug metabolism, pine.
Carissimi, A.S., L.C.A.A. Chaguri, M.A. Teixeira, C.M.C. Mori, M. Macchione, E.T.G. Sant'Anna, P.H.N. Saldiva, N.L. Souza, and J.B.L. Merusse (2000). Effects of two ventilation systems and bedding change frequency on cage environmental factors in rats (Rattus norvegicus). Animal Technology 51(3): 161-170. ISSN: 0264-4754.
NAL Call Number: QL55.I5
Descriptors: rats, laboratory animals, litter, cleaning, frequency, ventilation, ammonia, air flow, epithelium, nose, respiratory system, membrane potential, cilia, activity.
Carson, R. (1997). Adult squirrel caging. Journal of Wildlife Rehabilitation 20(2): 14. ISSN: 1071-2232.
Descriptors: squirrel, adult, caging, housing techniques, cage design.
Casey, A.M. and S.J. Casey (1998). Simple things that make a difference: design and plans for a juvenile squirrel cage. Journal of Wildlife Rehabilitation 21(2): 30-31. ISSN: 1071-2232.
Descriptors: squirrel, housing techniques, cage design, rehabilitation.
Chaguri, L.C.A.G., N.L. Souza, M.A. Teixeira, C.M.C. Mori, A.S. Carissimi, and J.L.B. Merusse (2001). Evaluation of reproductive indices in rats (Rattus norvegicus) housed under an intracage ventilation system. Contemporary Topics in Laboratory Animal Science 40(5): 25-30. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: rats, laboratory animals, animal housing, artificial ventilation, air flow, wind speed, female fertility, fecundity, litter weight, litter performance, liveweight gain, weaning weight, mortality.
Champy, M.F., M. Selloum, L. Piard, V. Zeitler, C. Caradec, P. Chambon, and J. Auwerx (2004). Mouse functional genomics requires standardization of mouse handling and housing conditions. Mammalian Genome 15(10): 768-783. ISSN: 0938-8990.
Abstract: The study of mouse models is crucial for the functional annotation of the human genome. The recent improvements in mouse genetics now moved the bottleneck in mouse functional genomics from the generation of mutant mice lines to the phenotypic analysis of these mice lines. Simple, validated, and reproducible phenotyping tests are a prerequisite to improving this phenotyping bottleneck. We analyzed here the impact of simple variations in animal handling and housing procedures, such as cage density, diet, gender, length of fasting, as well as site (retro-orbital vs. tail), timing, and anesthesia used during venipuncture, on biochemical, hematological, and metabolic/endocrine parameters in adult C57BL/6J mice. Our results, which show that minor changes in procedures can profoundly affect biological variables, underscore the importance of establishing uniform and validated animal procedures to improve reproducibility of mouse phenotypic data.
Descriptors: mouse, handling, housing, standardization, genomics, genetics, changes, model.
Clark Jr., J.A., P.H. Myers, M.F. Goelz, J.E. Thigpen, and D.B. Forsythe (1997). Pica behavior associated with buprenorphine administration in the rat. Laboratory Animal Science 47(3): 300-303. ISSN: 0023-6764.
NAL Call Number: 410.9 P94
Abstract: Marked gastric distention was observed in rats 20 h after they underwent partial hepatectomy under isoflurane anesthesia and received buprenorphine (0-3 mg/kg of body weight) after surgery. Hardwood bedding comprised the bulk of the gastric contents. A study was undertaken to determine the cause of the pica behavior (consumption of non-nutritive substances) and resultant gastric distention. Ten-week-old male Sprague Dawley rats were randomly assigned to one of six groups. Group-1 rats (n = 11) underwent laparotomy under isoflurane anesthesia, with buprenorphine (0.03 mg/kg) administered after surgery. Group-2 rats (n = 12) underwent laparotomy under isoflurane anesthesia, with buprenorphine (0.05 mg/kg) administered after surgery. Group-3 rats (n = 24) underwent laparotomy under isoflurane anesthesia, with saline administered after surgery. Isoflurane was administered at the same rate, concentration, and duration for all groups that underwent laparotomy (groups 1 to 3). Buprenorphine or saline was administered subcutaneously as a single injection when anesthesia was discontinued (groups 1 to 3). Group-4 rats (n = 6) received buprenorphine (0.3 mg/kg) only. Group-5 rats (n = 6) received buprenorphine (0.05 mg/kg) only. Group-6 rats (n = 12) received saline only. Rats not undergoing laparotomy (groups 4 to 6) received buprenorphine or saline 18 to 20 h before euthanasia. Rats were housed individually in filter-topped polycarbonate cages containing hardwood bedding. A purified, pelleted diet and water were offered ad libitum. Food and water consumption were measured over the posttreatment period. Eighteen to 20 h after treatment, rats were euthanized, each stomach and its contents were weighed, contents. were examined grossly, and wet and dry gastric content weights were recorded. All weights were significantly (P <0.05) increased in rats receiving buprenorphine administered after surgery (groups 1 and 2), compared with rats of the control group (group 3). Weights of the stomach and contents, wet gastric contents, and dry gastric contents were significantly (P <0.05) increased in rats receiving 0.3 mg of buprenorphine/kg only (group 4), compared with values for their controls (group 6). Hardwood bedding comprised the bulk of the gastric contents in all groups receiving buprenorphine. Stomachs of rats not receiving buprenorphine contained the purified diet with little or no hardwood bedding. These results indicate that a single injection of buprenorphine at a dosage of 0.05 or 0.3 mg/kg resulted in rats ingesting hardwood bedding, leading to gastric distention. It was concluded that pica behavior associated with administration of buprenorphine should be considered when evaluating experimental data from rats housed on contact bedding.
Descriptors: analgesics, opioids, pica, litter, stomach, digesta, rats, hepatectomy, laparotomy, anesthetics, postoperative complications, opioid analgesics, gastric distention, isoflurane.
Compton, S.R., F.R. Homberger, F.X. Paturzo, and J.M. Clark (2004). Efficacy of three microbiological monitoring methods in a ventilated cage rack. Comparative Medicine 54(4): 382-392. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: The use of individually ventilated caging (IVC) to house mice presents new challenges for effective microbiological monitoring. Methods that exploit the characteristics of IVC have been developed, but to the authors- knowledge, their efficacy has not been systematically investigated. Air exhausted from the IVC rack can be monitored, using sentinels housed in cages that receive rack exhaust air as their supply air, or using filters placed on the exhaust air port. To aid laboratory animal personnel in making informed decisions about effective methods for microbiological monitoring of mice in IVC, the efficacy of air monitoring methods was compared with that of contact and soiled bedding sentinel monitoring. Mice were infected with mouse hepatitis virus (MHV), mouse parvovirus (MPV), murine rotavirus (agent of epizootic diarrhea of mice [EDIM]), Sendai virus (SV), or Helicobacter spp. All agents were detected using contact sentinels. Mouse hepatitis virus was effectively detected in air and soiled bedding sentinels, and SV was detected in air sentinels only. Mouse parvovirus and Helicobacter spp. were transmitted in soiled bedding, but the efficacy of transfer was dependent on the frequency and dilution of soiled bedding transferred. Results were similar when the IVC rack was operated under positive or negative air pressure. Filters were more effective at detecting MHV and SV than they were at detecting MPV. Exposure of sentinels or filters to exhaust air was effective at detecting several infectious agents, and use of these methods could increase the efficacy of microbiological monitoring programs, especially if used with soiled bedding sentinels. In contemporary mouse colonies, a multi-faceted approach to microbiological monitoring is recommended.
Descriptors: ventilated caging, mice, microbiological monitoring, filters, sentinals, IVC, bedding.
Crabbe, J.C. and D. Wahlsten (2003). Of mice and their environments. Science 299(5611): 1313-4. ISSN: 1095-9203.
Descriptors: mice, environment, housing, behavior, animal husbandry, mutant strains, species specificity.
D'Arbe, M., R. Einstein, and N.A. Lavidis (2002). Stressful animal housing conditions and their potential effect on sympathetic neurotransmission in mice. American Journal of Physiology Regulatory, Integrative and Comparative Physiology 282(5): R1422-8. ISSN: 0363-6119.
Abstract: Although the sympathetic nervous system (SNS) plays a major role in mediating the peripheral stress response, due consideration is not usually given to the effects of prolonged stress on the SNS. The present study examined changes in neurotransmission in the SNS after exposure of mice (BALB/c) to stressful housing conditions. Focal extracellular recording of excitatory junction currents (EJCs) was used as a relative measure of neurotransmitter release from different regions of large surface areas of the mouse vas deferens. Mice were either group housed (control), isolation housed (social deprivation), group housed in a room containing rats (rat odor stress), or isolation housed in a room containing rats (concurrent stress). Social deprivation and concurrent stressors induced an increase of 30 and 335% in EJC amplitude, respectively. The success rate of recording EJCs from sets of varicosities in the concurrent stressor group was greater compared with all other groups. The present study has shown that some common animal housing conditions act as stressors and induce significant changes in sympathetic neurotransmission.
Descriptors: mice, housing conditions, stress, potential effect, sympathetic nervous system, group housed, isolation housed.
Davey, A.K., J.P. Fawcett, S.E. Lee, K.K. Chan, and J.C. Schofield (2003). Decrease in hepatic drug-metabolizing enzyme activities after removal of rats from pine bedding. Comparative Medicine 53(3): 299-302. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: Wood is often used as a contact bedding material for laboratory animals. It has been established that wood, particularly softwood, has the potential to induce hepatic drug-metabolizing enzymes. However, to the authors' knowledge, changes in enzyme activity after removal of animals from bedding have not been characterized. The purpose of the study reported here was to determine how hepatic ethoxyresorufin-O-deethylation and p-nitrophenol hydroxylation activities alter over time after removal of rats from pine bedding. Male rats, three to four months old, raised in cages containing pine bedding, were transferred to wire-bottomed cages. At various times thereafter (up to 84 days), groups of rats were euthanized and the liver was processed to obtain microsomes. The microsomal protein and total cytochrome P450 (CYP) content and enzyme activities were determined. Significant differences in total microsomal protein or total CYP values were not observed over the 84 days, but a decrease in ethoxyresorufin-O-deethylation and p-nitrophenol hydroxylation activities was detected. For p-nitrophenol hydroxylation, the decrease was exponential, with a half-life of approximately nine days, whereas for ethoxyresorufin-O-deethylation, a rapid decrease in activity in the first week was followed by a reduced rate of decrease thereafter. Enzyme activities did not stabilize for at least six weeks. Researchers using laboratory animals should, therefore, be aware that it takes several weeks for enzyme activities to stabilize once animals are removed from the bedding.
Descriptors: rats, laboratory animals, litter bedding, wood residues, gene induction, enzyme activity, cytochrome P450, liver microsomes, 7 ethoxyresorufin-O-deethylase, p-nitrophenol hydroxylation.
De Groot, M.H. and B. Rusak (2004). Housing conditions influence the expression of food-anticipatory activity in mice. Physiology and Behavior 83(3): 447-457. ISSN: 0031-9384.
Abstract: If food is presented for a limited duration once every 24 h, rats will gradually develop increased activity in the hours preceding mealtime, even if this is during a time of day when they are normally inactive. This food-anticipatory activity (FAA) is mediated by the entrainment of an endogenous self-sustaining circadian pacemaker. Mice are increasingly being used for the molecular analysis of behavior because of the large number of genetically manipulated mouse models available, but little is known about food entrainment in this species. This study assessed the impact of different housing conditions on the expression of FAA in a temporally restricted feeding paradigm. Wheel-running activity rhythms were recorded from mice (Mus musculus) undergoing food restriction while housed under one of two conditions. The results demonstrated that mice housed on open shelves showed robust FAA while those housed in isolation boxes did not. These results indicate that differences in susceptibility to food entrainment among mice (e.g., those with different genotypes) should be interpreted cautiously, since at least one strain is strongly affected by a relatively minor procedural difference that was not anticipated to have a significant impact.
Descriptors: mice, housing conditions, food anticipatory activity, influence, behavior, limited duration, isolation.
De Jager, L., L. De Bruyn, and F.J. Potgieter (1997). Effect of vermiculite bedding material on the incidence of lung malignancy: implications for case-control studies. Animal Technology 48(1): 1-6. ISSN: 0264-4754.
NAL Call Number: QL55.I5
Abstract: With the use of small animals in long-term biological research studies the microenvironment plays an important role. Vermiculite, a widely used bedding material, conforms to all the requirements of a good bedding material, but histological changes in the lungs and lung tumors have been reported. To examine the alleged carcinogenic effect of vermiculite a case-control study was undertaken. An experimental group of mice, Mus musculus, strain BALB/c, was maintained on vermiculite bedding material and a control group, kept in the same room, on cotton wool as bedding material. Both groups were sacrificed at the age of 18 months, and the lungs were examined macroscopically at autopsy. Histological preparations of the lungs were studied to detect and identify lung tumors. The incidence of diagnosed malignant tumors in both groups was recorded. White oval masses, identified histologically as alveologenic tumors of type II alveolar cell origin, were recorded in both groups. A significantly higher incidence of lung tumors was found in the experimental group. The BALB/c strain is a useful animal model for screening lung carcinogenesis because of its susceptibility to lung tumor development. In this study a higher incidence of alveologenic lung tumors in the experimental group further proves the carcinogenic effect of vermiculite. These findings could implicate misinterpretation of results in life-span and carcinogenicity studies on mice as well as detrimental health effects for human beings working with the animals.
Descriptors: mice, strains, vermiculite, litter, carcinogens, lungs, neoplasms, histopathology, carcinogenesis, occupational health, laboratory workers.
Dorshkind, K., L. Welniak, R.A. Gault, J. Hixon, E. Montecino Rodriguez, N.D. Horseman, J.M. Gertner, and W.J. Murphy (2003). Effects of housing on the thymic deficiency in dwarf mice and its reversal by growth hormone administration. Clinical Immunology 109(2): 197-202. ISSN: 1521-6616.
Abstract: Abstract Initial studies on T cell development in the Snell Dwarf (dw/dw) strain of mice, which are deficient in the production of anterior pituitary hormones, have been interpreted to indicate a clear dependence of T cell development on endocrine system-derived factors. However, normal thymopoiesis in this strain has also been reported. The aim of the present study was to reconcile these contradictory data in order to define the role of anterior pituitary hormones in the thymus. The results indicated that if female dw/dw mice are housed together with their normal-sized littermates, thymic cellularity and the frequency of CD4 super(+)CD8 super(+) thymocytes are markedly reduced. However, administration of growth hormone could reverse these decreases seen in the double-positive T progenitor cells. Taken together, the data indicate that stress is the unifying parameter that can explain the disparate dw/dw mouse literature and suggest that endocrine effects on the T cell development can best be understood by interpreting the literature in this context.
Descriptors: dwarf mice, thymic deficiency, housing effect, reversal, growth hormone, housing.
Douglas, L.A., E.I. Varlinskaya, and L.P. Spear (2004). Rewarding properties of social interactions in adolescent and adult male and female rats: impact of social versus isolate housing of subjects and partners. Developmental Psychobiology 45(3): 153-162. ISSN: 0012-1630.
Descriptors: behavior, development, social conditioned place preference, social interaction.
Engleman, E.A., C.M. Ingraham, C.E. O'Brien, W.J. McBride, and J.M. Murphy (2004). Effect of housing conditions on sulpiride-induced increases in extracellular dopamine (DA) levels in the nucleus accumbens of alcohol-preferring (P) rats. Brain Research 1022(1-2): 247-250. ISSN: 0006-8993.
Abstract: The effect of housing conditions on sulpiride-induced increases in extracellular dopamine (DA) levels was investigated in the nucleus accumbens (NAC) of P rats. Rats were double-housed (DH) in plastic tubs, or single-housed (SH) in hanging wire cages for 12 weeks. Microdialysis in the NAC showed greater sulpiride-induced DA increases in the NAC of SH vs. DH rats, with no difference in basal levels. The data indicate that housing conditions can alter DA D(2) receptor function in the NAC.
Descriptors: housing conditions, effect, sulpiride-induced increases, extracellular dopamine, rats, alcohol preferring.
Eriksson, E., F. Royo, K. Lyberg, H.E. Carlsson, and J. Hau (2004). Effect of metabolic cage housing on immunoglobulin A and corticosterone excretion in faeces and urine of young male rats. Experimental Physiology 89(4): 427-33. ISSN: 0958-0670.
Descriptors: rats, corticosterone, urine, feces, housing, immunoglobulin A, stress, male, Sprague Dawley rats, metabolic cageing.
Eskola, S. and E. Kaliste Korhonen (1999). Nesting material and number of females per cage: effects on mouse productivity in BALB/c, C57BL/6J, DBA/2 and NIH/S mice. Laboratory Animals 33(2): 122-128. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Two different materials--aspen wood-wool and paper towel--were compared as nesting material for three inbred mouse strains (BALB/c, C57BL/6J and DBA/2) housed in barrier conditions. In addition, the effect of varying the number of females per cage (one to three per cage) of these three strains and with NIH/S outbred mouse stock was studied. The number of litters, litter size and neonatal mortality were determined, as well as age, sex and weight of weanlings. The type of nesting material did not affect the characteristics monitored. In all strains, the number of weanlings per female was greatest in singly-housed females. In terms of the number of weanlings per cage, two females per cage gave the best result. In DBA/2 mice, neonatal mortality increased when several females were caged together.
Descriptors: mice, female animals, nesting, cage density, wood wool, paper, litter, strain differences, barrier husbandry, female fertility, litter size, age at weaning, weaning weight, mortality, inbreeding depression, paper towels.
Eskola, S. and E. Kaliste Korhonen (1999). Aspen wood-wool is preferred as a resting place, but does not affect intracage fighting of male BALB/c and C57BL/6J mice. Laboratory Animals 33(2): 108-121. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Aspen wood-wool, provided as nesting material, was evaluated as a possible improvement of cage environment for 10-14-week-old inbred male mice maintained in groups of six (BALB/c n = 72 and C57BL/6J n = 36). The daily behaviour of mice was video recorded and their body weight, food consumption, weights of some organs and serum corticosterone concentrations were measured. Aggressive interactions between cage mates and against a strange intruder as well as the number of wounds on the back of the animals was monitored in order to evaluate the effect of nesting material on intermale aggression. Nesting material did not affect the daily active/passive behaviour patterns of mice, although animals clearly preferred it as a resting place. BALB/c mice given nesting material showed less weight gain and smaller brown adipose tissue weights than animals without nesting material. The other characteristics measured were not affected by the presence of nesting material in either strain. The presence of nesting material had no effect on fighting in cages. C57BL/6J mice were more aggressive than BALB/c mice according to the number of wounded animals in a cage. Wounded BALB/c mice had enlarged spleens and decreased epididymal adipose tissue weights. In conclusion, the nesting material used in this study did not adversely affect the animals. On the other hand, the material was clearly preferred to conventional bedding as a resting place. These findings suggest that nesting material may improve the cage environment of laboratory mice. Furthermore, there was an indication of strain differences in aggressive behaviour. It could be suggested that C57BL/6J mice are less tolerant towards intruders and. housing six mice per cage is not suitable for this strain.
Descriptors: mice, male animals, strain differences, cages, wood wool, physical activity, nesting, aggressive behavior, body weight, liveweight gain, adrenal glands, spleen, weight, brown fat, blood serum, corticosterone, body fat, cage density, epididymal fat.
Ewaldsson, B., B. Fogelmark, R. Feinstein, L. Ewaldsson, and R. Rylander (2002). Microbial cell wall product contamination of bedding may induce pulmonary inflammation in rats. Laboratory Animals 36(3): 282-290. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: To test the hypothesis that airborne microbial cell wall components could induce an inflammatory response in the lungs, measurements were made of the amounts of bacterial endotoxin and (1 leads to 3)-beta-D-glucan in laboratory animal bedding materials. Groups of rats were exposed by inhalation to airborne endotoxin, (1 leads to 3)-beta-D-glucan or a combination of the two for 5 weeks. The results demonstrated that measurable amounts of endotoxin and (1 leads to 3)-beta-D-glucan could be detected in the different bedding materials. In contrast to animals at delivery, those kept on bedding for 5 weeks showed moderate inflammatory reactions in the lung. These were most pronounced among animals exposed to endotoxin and (1 leads to 3)-beta-D-glucan. The results suggest that further studies need to be undertaken to elucidate the role of microbial cell wall products in the development of inflammatory lung responses among research animals.
Descriptors: rats, laboratory mammals, air pollutants, aerosols, cell walls, glucans, endotoxins, litter, microbial contamination, lungs, inflammation, histiocytes, macrophages, histopathology, experimental design.
Francolin Silva, A.L. and S.S. Almeida (2004). The interaction of housing condition and acute immobilization stress on the elevated plus-maze behaviors of protein-malnourished rats. Brazilian Journal of Medical and Biological Research 37(7): 1035-1042. ISSN: 0100-879X.
Abstract: Protein malnutrition induces structural, neurochemical and functional alterations in the central nervous system, leading to behavioral alterations. In the present study, we used the elevated plus-maze (EPM) as a measure of anxiety to evaluate the interaction between acute immobilization and housing conditions on the behavior of malnourished rats. Pups (6 males and 2 females) were fed by Wistar lactating dams receiving a 6% (undernourished) or 16% (well-nourished) protein diet. After weaning, the animals continued to receive the same diets ad libitum until 49 days of age when they started to receive a regular lab chow diet. From weaning to the end of the tests on day 70, the animals were housed under two different conditions, i.e., individual or in groups of three. On the 69th day, half of the animals were submitted to immobilization for 2 h, while the other half were undisturbed, and both groups were tested 24 h later for 5 min in the EPM. Independent of other factors, protein malnutrition increased, while immobilization and social isolation per se decreased, EPM exploration. Analysis of the interaction of diet vs immobilization vs housing conditions showed that the increased EPM exploration presented by the malnourished group was reversed by acute immobilization in animals reared in groups but not in animals reared individually. The interaction between immobilization and housing conditions suggests that living for a long time in social isolation is sufficiently stressful to reduce the responses to another anxiogenic procedure (immobilization), while living in groups prompts the animals to react to acute stress. Thus, it is suggested that housing condition can modulate the effects of an anxiogenic procedure on behavioral responses of malnourished rats in the EPM.
Descriptors: rats, protein malnourished, housing condition, interaction, stress, behavior, diet, immobilization.
Gaertner, D.J., M. Batchelder, L.H. Herbst, and H.L. Kaufman (2003). Administration of vaccinia virus to mice may cause contact or bedding sentinel mice to test positive for orthopoxvirus antibodies: case report and follow-up investigation. Comparative Medicine 53(1): 85-88. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: Routine testing of bedding sentinels from a barrier room revealed one mouse seropositive to ectromelia virus (EV). Results of hemagglutination-inhibition testing and western blot analysis were confirmatory for orthopoxvirus antibodies. Additional seropositive animals were not identified. Interviews indicated that replication-competent vaccinia virus (VV), Western Reserve strain (VV-WR), recently had been given to mice. Although VV-WR was not expected to spread by contact or via fomites, the case evidence suggested transmission of vaccinia via soiled bedding. In a follow-up experiment, 15 index mice were inoculated with 107 plaque-forming units of VV by either subcutaneous or intrarectal instillation. A dedicated contact sentinel and a bedding sentinel were provided for each index mouse. All 15 index mice were positive for antibodies when tested 22 days after inoculation. One mouse, inoculated by the subcutaneous route, appeared ill and developed lesions on the proximal portion of the tail. The contact sentinel mouse housed with this index mouse was the only sentinel to seroconvert. We conclude that VV-WR can spread to contact sentinels and potentially to bedding sentinels. The ability of other VV strains to be transmitted horizontally and the susceptibility of different mouse strains to infection merit further investigation. The use of VV in animal facilities must be managed carefully since the available serologic tests do not distinguish between VV and EV, an exotic agent of major concern to laboratory animal facilities.
Descriptors: mice, laboratory animals, vaccinia virus, sentinel animals, case reports, horizontal transmission, litter, feces, seroconversion, cross reaction, barrier husbandry, myobia, disease transmission, ectromelia virus.
Galani, R., E. Duconseille, O. Bildstein, and J.C. Cassel (2001). Effects of room and cage familiarity on locomotor activity measures in rats. Physiology and Behavior 74(1-2): 1-4. ISSN: 0031-9384.
Abstract: Locomotor activity measures are often used in behavioral neuroscience. There is, however, a large variability in the protocols assessing locomotor activity which may, more or less, strongly be influenced by exploration and reactivity to novelty in unfamiliar situations. Using Long-Evans male rats, we investigated how far changes, such as placing rats in a cage physically identical to the home cage supplied with fresh sawdust but kept in a familiar room, or placing the familiar home cage with the rat inside in another (unfamiliar) room, may influence the level of locomotor activity. We showed that both changes resulted in significantly increased locomotion in the first 2 h after placing the rats in the respective test situation, but there is no significant additive effect. These changes performed right before the start of the test do not alter diurnal or nocturnal locomotor activity once the first 2 h have elapsed. The results illustrate that rats kept in an environment with stable proximal features (cage, sawdust) can react by increased activity in response to more distal novelty (experimental room), and conversely, that rats in a familiar environment react to proximal changes in the home cage.
Descriptors: Long Evans rats, cage familiarity, locomotor activity, effects, room, behavior, exploration.
Garey, J., L. Kow, W. Huynh, S. Ogawa, and D.W. Pfaff (2002). Temporal and spatial quantitation of nesting and mating behaviors among mice housed in a semi-natural environment. Hormones and Behavior 42(3): 294-306. ISSN: 0018-506X.
Descriptors: mice, nesting, mating, behavior, environment, natural, social interactions.
Garrett Beal, L.J. and S.L. Hoogstraten (2003). Managing a mouse mutant resource center...this is not your father's transgenic core. Lab Animal 32(8): 31-7. ISSN: 0093-7355.
NAL Call Number: QL55.A1L33
Abstract: Genetically engineered mice are making an increasingly valuable contribution to biomedical research, and many institutions have begun to assemble dedicated facilities for the development of transgenic animals. The authors describe the structure, function, and management of the transgenic core at NHGRI.
Descriptors: mouse, mutant resource center, transgenic, veterinary medicine, methods, disease models, regional health planning.
Georgsson, L., J. Barrett, and D. Gietzen (2001). The effects of group-housing and relative weight on feeding behaviour in rats. Scandinavian Journal of Laboratory Animal Science 28(4): 201-209. ISSN: 0901-3393.
Descriptors: rats, group housing, weight, feeding behavior, effect.
Language of Text: Swedish summary.
Gil, M.C., J.A. Aguirre, A.P. Lemoine, E.T. Segura, M. Barontini, and I. Armando (1999). Influence of age on stress responses to metabolic cage housing in rats. Cellular and Molecular Neurobiology 19(5): 625-33. ISSN: 0272-4340.
Abstract: 1. We studied the effect of isolation stress in 3- and 12-month-old rats individually housed in metabolic cages for 7 days. Urine (24 hr) was collected daily from one group of animals of each age. The other group was tested in an open field and on a hot plate on days 1 and 7. 2. Total deambulation in the open-field test was lower in young than in older rats both on day 1 (54.7 +/- 9.9 vs 80 +/- 8.9 crossings/session; P < 0.04) and on day 7 (21 +/- 9 vs 48 +/- 7 crossings per session; P < 0.04) and decreased significantly in the two groups when tested on day 7 (P < 0.03). Latency to paw-licking in the hot-plate test was longer in young than in older animals on day 1 (14 +/- 2 vs 8 +/- 4 sec; P < 0.05) but was similar in the two groups on day 7. 3. Urinary excretions of norepinephrine (NE) and epinephrine (E) were determined by HPLC with electrochemical detection. Urinary NE in day 1 was similar in young and older animals (2627 +/- 828 vs 3069 +/- 598 ng/24 hr). In young animals NE excretion decreased along the study and was significantly (P < 0.02) lower than on day 1 during the last 3 days of the study. Conversely, in older animals urinary excretion of NE remained similar throughout the study. On day 7 urinary excretion of NE in older animals was about two fold that in young rats. Urinary E was similar in young and older rats (341 +/- 127 vs 532 +/- 256 ng/24 hr) on day 1 and showed a tendency to increase throughout the study. 4. Urinary monoamine oxidase inhibitory (IMAO) activity was determined by testing the ability of urine extracts to inhibit rat liver MAO activity in vitro and was higher in young than in older animals throughout the study (day 1, 54.8 +/- 4.2 vs 25.1 +/- 5.1%; P < 0.02). In young rats excretion of IMAO was significantly higher during the last 3 days of the study than on day 1 (P < 0.05). In older animals urinary IMAO showed a tendency to increase at the end of the study. 5. Isolation stress caused by housing rats in metabolic cages results in different behavioral and metabolic responses in young and older animals. Young animals exhibit a lower locomotor and analgesic response and excrete lower amounts of NE and higher IMAO activity in the urine than older rats. The metabolic and behavioral responses to isolation stress are highly dependent on the age of the animals tested. These results should be taken into consideration when designing experiments requiring the use of metabolic cages.
Descriptors: metabolic cage housing, rats, age, influence, stress, factors, heat, social isolation, behavior.
Gordon, C.J. (2004). Effect of cage bedding on temperature regulation and metabolism of group-housed female mice. Comparative Medicine 54(1): 63-68. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: Mice are generally housed in groups in cages lined with an absorbent bedding material at ambient temperature (Ta) of 20 to 24+C, which is comfortable for humans, but cool for mice. Little is known about the effects of bedding on thermoregulation of group-housed mice. To determine whether bedding material affects thermoregulatory stability, core temperature (Tc) and motor activity (MA) were monitored by use of radiotelemetry in female CD-1 mice housed in groups of four in a standard plastic cage at Ta of 23.5+C. Ten groups were tested using three types of bedding material: a deep layer of heat-treated wood shavings (DWS) that allowed mice to burrow, a thin layer of wood shavings (TWS) just covering the bottom of the cage floor, or a layer of beta chips (BC). Mice could not burrow in the TWS or BC. The Tc and MA were affected by bedding type and time of day. Mice housed with DWS maintained a significantly higher Tc (deltaTc = 1.0+C) during the day, compared with that in mice housed with TWS and BC. During the night, Tc and MA were high in all groups and there was no effect of bedding type on Tc or MA. Effect of bedding on metabolic rate (MR) was estimated by measuring oxygen consumption for six hours in groups of four mice at Ta of 23.5+C. The Tc was significantly reduced in mice housed on the TWS and BC, but MR was unaffected by bedding type. There was a trend for higher MR in mice on BC. Compared with use of other bedding materials, housing mice on DWS and comparable materials provides an environment to burrow, thus reducing heat loss. The effects of bedding material on temperature regulation may affect rodent health and well being. Moreover, bedding will affect variability in toxicologic and pharmacologic studies whenever an endpoint is dependent on body temperature.
Descriptors: laboratory animals, group housing, thermoregulation, litter bedding, ambient temperature, body temperature, mice, temperature regulation, housing, effect, female.
Gordon, C.J., P. Becker, and J.S. Ali (1998). Behavioral thermoregulatory responses of single- and group-housed mice. Physiology and Behavior 65(2): 255-62. ISSN: 0031-9384.
Abstract: The ambient temperature (Ta) to house and study laboratory rodents is critical for nearly all biomedical studies. The ideal Ta for housing rodents and other animals should be based on their thermoregulatory requirements. However, fundamental information on the behavioral thermoregulatory responses of single- and group-housed rodents is meager. To address this issue, thermoregulatory behavior was assessed in individual and groups of CD-1 mice housed in a temperature gradient. Mice were housed in groups of five or individually while selected Ta and motor activity were monitored. Single- and group-housed mice displayed a circadian oscillation of selected Ta and motor activity with relatively warm T(a)s of approximately 29 degrees C selected during the light phase; during the dark phase selected Ta was reduced by 4 degrees C, whereas motor activity increased. Selected Ta of aged (11 months old) mice housed individually was approximately 1.0 degrees C warmer than the group-housed mice. Thermal preference of younger mice (2 months old) was similar for single- and group-housed animals. The operative Ta of mice housed in standard facilities was estimated by measuring the cooling rate of "phantom" mice modeled from aluminum cylinders. The results show that the typical housing conditions for single- and group-housed mice are cooler than their Ta for ideal thermal comfort.
Descriptors: behavior, animal physiology, body temperature regulation physiology, social isolation, aging physiology, circadian rhythm physiology, housing, animal, mice, motor activity physiology, temperature, time factors.
Hasegawa, M., S. Kagiyama, M. Tajima, K. Yoshida, Y. Minami, and T. Kurosawa (2003). Evaluation of a forced-air-ventilated micro-isolation system for protection of mice against Pasteurella pneumotropica. Experimental Animals (Tokyo) 52(2): 145-51. ISSN: 1341-1357.
Abstract: Studies to date have established that the physical environment inside cages can be controlled adequately by setting the intra-cage ventilation at 60 air changes per hour in a forced-air-ventilated micro-isolation system (FVMIS). In this study, the capability of FVMIS to prevent inter-cage transmission of microorganisms was evaluated using Pasteurella pneumotropica as a reference microorganism. One FVMIS rack and a conventional rack were used, and cages with mice positive for P. pneumotropica and those with P. pneumotropica-free mice were housed on both racks. The mice were examined for P. pneumotropica contamination every 4 weeks after initiating the experiment for 12 weeks using a polymerase chain reaction method. Some P. pneumotropica-free mice housed in open air cages in the conventional rack became positive for P. pneumotropica (four of 28 animals after 4 weeks; eight of 28 animals after 12 weeks), but all P. pneumotropica-free mice housed in the FVMIS cages remained negative for the bacterium throughout the experiment. The results demonstrate that FVMIS can prevent inter-cage transmission of P. pneumotropica when proper cage handling practice is under taken.
Descriptors: mice, Pasteurella pathogenicity, ventilation, forced air, air changes, transmission, microorganisms.
Haseman, J.K., E. Ney, A. Nyska, and G.N. Rao (2003). Effect of diet and animal care/housing protocols on body weight, survival, tumor incidences, and nephropathy severity of F344 rats in chronic studies. Toxicologic Pathology 31(6): 674-81. ISSN: 0192-6233.
Abstract: Diet is an important environmental factor affecting body weight, survival, and age-related diseases of rodents. The NIH-07 open formula diet was the diet used in the National Toxicology Program's (NTPs) rodent carcinogenicity studies from 1980 to 1994. In 1994 the NTP began using a new diet designated the NTP-2000 diet. This paper compares body weight, survival, tumor incidence, and nephropathy severity in untreated control groups of Fischer 344 (F344) rats fed the NTP-2000 or NIH-07 diets, using data from 22 separate 2-year feed and inhalation studies. The feed studies were conducted in 3 different facilities, and all the inhalation studies were conducted in a single facility. During feed studies, rats were group housed in polycarbonate cages and fed diets in powder (mash) form, while in inhalation studies, rats were housed individually in wire mesh cages, and fed diets in pelleted form. Survival was significantly (p<0.05) higher in groups fed NTP-2000 diet compared to the corresponding groups fed NIH-07 diet, irrespective of sex or housing conditions. Use of the NTP-2000 diet was also associated with a decreased incidence of pituitary gland tumors in both sexes and decreased incidences of adrenal pheochromocytoma and preputial gland tumors in males. The incidence and severity of nephropathy was also decreased in animals receiving the NTP-2000 diet, especially males. The decreased nephropathy severity and the decreased incidence of pituitary gland tumors are likely the major factors contributing to the improved survival of rats receiving the NTP-2000 diet relative to those given the NIH-07 diet. These data also support earlier findings that decreased incidences of adrenal pheochromocytoma are associated with reduced nephropathy severity in male F344 rats. Throughout the two-year study female rats receiving the NTP-2000 diet were significantly (p<0.05) lighter than those receiving the NIH-07 diet. However, it is uncertain if this difference can be attributed to the NTP-2000 diet, since implementation of this diet by the NTP approximately coincided with changes in the F344 rat production colony that resulted in somewhat lighter animals being provided to the NTP. Controls from inhalation studies and feed studies differed significantly (p<0.01) in the incidence of a variety of tumors, irrespective of diet. This suggests that differences in animal care and housing protocols may impact tumor incidence in F344 rats, most notably pituitary gland and testis tumors.
Descriptors: animal feed analysis, animal husbandry methods, body weight physiology, kidney diseases pathology, longevity physiology, neoplasms epidemiology, toxicity tests, chronic methods, food, formulated analysis, housing, animal, neoplasms pathology, rats, inbred F344 rats.
Hawkins, P., D. Anderson, K. Applebee, D. Key, J. Wallace, G. Milite, J.M. Clark, R. Hubrecht, and M. Jennings (2003). Individually ventilated cages and rodent welfare: report of the 2002 RSPCA/UFAW Rodent Welfare Group meeting. Animal Technology and Welfare 2(1): 23-34. ISSN: 0264-4754.
NAL Call Number: SF757.A62
Descriptors: rodent, animal housing, animal welfare, individually ventilated cages, laboratory animals, mice, UFAW.
Heikkilae, M., R. Sarkanen, H.M. Voipio, and T. Nevalainen (2001). Cage position preferences of rats. Scandinavian Journal of Laboratory Animal Science 28(2): 65-74. ISSN: 0901-3393.
Descriptors: rats, laboratory animals, animal husbandry, cages, behavior, animal housing, preferences, position.
Hesler, J.R., J.R. Broderson, and C.S. King (1999). Rodent quarantine: facility design and equipment for small animal containment facilities. Lab Animal 28(8): 34-40. ISSN: 0093-7355.
NAL Call Number: QL55.A1L33
Descriptors: mice, rats, laboratory mammals, transgenic animals, animal health, disease transmission, quarantine, barrier husbandry, cages, animal housing, air flow, artificial ventilation, safety at work, autoclaving, animal cubicles, airlocks, air pressure.
Hobbs, B.A., S. Herrmann, J. Muzzicato, and M. Smith (1997). Comparison of the effect of two automatic watering systems and environmental manipulations on frequency of wet bedding created by mice housed in solid-bottom suspended caging systems. Contemporary Topics in Laboratory Animal Science 36(6): 69-71. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: mice, cages, litter, water systems, automatic control, comparisons, strain differences, sex differences, age differences, in the cage automatic watering systems, out of cage automatic watering systems.
Hoglund, A.U. and A. Renstrom (2001). Evaluation of individually ventilated cage systems for laboratory rodents: cage environment and animal health aspects. Laboratory Animals 35(1): 51-57. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: The use of individually ventilated cage (IVC) systems has become an attractive housing regime of laboratory rodents. The benefits of IVC systems are, reportedly, a high degree of containment combined with relative ease of handling, and a high degree of protection from allergenes. In the present study we tested whether two IVC systems (BioZone VentiRack, IVC1 and Techniplast SealSafe, IVC2S), in which we held mature male NMRI mice, were constructed to maintain a constant differential pressure, positive or negative, during a prolonged period of time. We also measured ammonia (NH3) concentrations after about 2 weeks of use, and CO2 build-up during a 60 min simulated power failure situation. In addition, animal weight development and bite-wound frequency were recorded (Renstrom et al. 2000). From the present study it is concluded that the IVC1 air handling system provides a more uniform and balanced differential pressure than the IVC2S. Both systems effectively scavenge NH3 when bedding material is not soaked by urine. Although the IVCs are dependent on the continual function of the fans to work properly, it seems unlikely that CO2 concentrations increase to hazardous levels, as a result of a one hour power failure, with the type of cages used in this study. Differences in weight development and bite-wound occurrence were noted between the two IVC systems. Causes for these differences could not be established and need more investigation.
Descriptors: mice, laboratory mammals, cages, design, artificial ventilation, animal husbandry, liveweight gain, bites, air pollution, ammonia, carbon dioxide, animal health, cage size, social dominance.
Hosokawa, M., T. Abe, K. Higuchi, K. Shimakawa, Y. Omori, T. Matsushita, K. Kogishi, E. Deguchi, Y. Kishimoto, K. Yasuoka, and T. Takeda (1997). Management and design of the maintenance of SAM mouse strains: an animal model for accelerated senescence and age-associated disorders. Experimental Gerontology 32(1-2): 111-116. ISSN: 0531-5565.
Descriptors: SAM mouse, strains, management, design, animal model, maintenance, age, associated disorders, senescence.
Hubrecht, R. (2000). Advancing rabbit and rodent housing and husbandry research. Progress in the Reduction, Refinement and Replacement of Animal Experimentation: Proceedings of the 3rd World Congress on Alternatives and Animal Use in the Life Sciences, Bologna, Italy, p. 1257-1267.
Descriptors: rabbit, rodent, housing, husbandry, animal welfare, enrichment, research.
Hurst, J.L., C.J. Barnard, R. Hare, E.B. Wheeldon, and C.D. West (1996). Housing and welfare in laboratory rats: time-budgeting and pathophysiology in single-sex groups. Animal Behaviour 52(2): 335-360. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: rats, behavior, social behavior, single sex groups, biological differences, pathophysiology, animal welfare.
Hurst, J.L., C.J. Barnard, C.M. Nevison, and C.D. West (1998). Housing and welfare in laboratory rats: the welfare implications of social isolation and social contact among females. Animal Welfare 7(2): 121-136. ISSN: 0962-7286.
NAL Call Number: HV4701.A557
Descriptors: rats, cages, group size, welfare, females, housing, behavior, social isoloation, blood serum, corticosterone, aggressive behavior.
Hurst, J.L., C.J. Barnard, C.M. Nevison, and C.D. West (1997). Housing and welfare in laboratory rats: welfare implications of isolation and social contact among caged males. Animal Welfare 6(4): 329-347. ISSN: 0962-7286.
NAL Call Number: HV4701.A557
Descriptors: rats, animal welfare, housing, behavior, social behavior, males, behavior, isolation, social contact.
Hurst, J.L., C.J. Barnard, U. Tolladay, C.M. Nevison, and C.D. West (1999). Housing and welfare in laboratory rats: effects of cage stocking density and behavioural predictors of welfare. Animal Behaviour 58(Part 3): 563-586. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: rats, stocking density, stress response, sex differences, physiopathology, animal welfare, aggressive behavior, grooming, physical activity, escape responses, kidneys, adrenal glands, IGG, thymus gland, corticosterone, blood serum, testosterone, blood picture, blood chemistry.
Ishii, T., K. Yoshida, M. Hasegawa, S. Mizuno, M. Okamoto, M. Tajima, and T. Kurosawa (1998). Invention of a forced-air-ventilated micro-isolation cage and rack system. Environment within cages: temperature and ammonia concentration. Applied Animal Behaviour Science 59(1-3): 115-123. ISSN: 0168-1591.
NAL Call Number: QL750.A6
Descriptors: rats, laboratory rearing, cages, environmental temperature, ammonia, animal welfare, artificial ventilation, air flow, litter, paper, wood chips.
Jensen, S.P., S.J. Gray, and J.L. Hurst (2003). How does habitat structure affect activity and use of space among house mice? Animal Behaviour 66(2): 239-250. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: mice, activity, habitat structure, space use, open site, protected site, food.
Johnson, E.C., M.M. Lavail, W.O. Cepurna, L. Jia, K. Ackhavong, and J.C. Morrison (1999). Housing in low level, constant light stabilizes circadian intraocular pressure (IOP) oscillations in brown norway rats, simplifying a glaucomatous neuropathy model. IOVS 40(4): S672.
Descriptors: Norway rats, housing, low level constant light, intraocular pressure, glaucomatous, meeting abstract.
Notes: Meeting Information: Annual Meeting of the Association for Research in Vision and Ophthalmology, May 9-14, 1999, Fort Lauderdale, Florida, USA.
Karolewicz, B. and I.A. Paul (2001). Group housing of mice increases immobility and antidepressant sensitivity in the forced swim and tail suspension tests. European Journal of Pharmacology 415(2-3): 197-201. ISSN: 0014-2999.
Abstract: The forced swim test and tail suspension test are often used in laboratory practice to identify compounds that possess antidepressant-like activity. This experiment was conducted to determine whether housing conditions per se influence the response of mice in these antidepressant screening procedures. Male NIH Swiss mice were housed individually or in groups (five per cage) for 8 weeks prior to testing. After 8 weeks, the animals were exposed to the forced swim and tail-suspension tests. Group housed mice displayed high levels of immobility in the forced swim and tail suspension tests. Desipramine injection 60 min prior testing, in doses 7.5 and 15 mg/kg, produced significant reductions in the immobility time in forced swimming and tail suspension tests. Individually housed mice, when exposed to these tests, displayed lower levels of immobility with a magnitude comparable to the effect of desipramine in group housed mice. Desipramine given to individually housed mice did not reduce the duration of immobility either in the forced swim test or in the tail suspension test. These results indicate that both tests are sensitive to housing conditions. This observation suggests that long lasting group housing may be critical to the behavioral response in these preclinical screening procedures in mice.
Descriptors: antidepressive agents, tricyclic pharmacology, behavior, animal drug effects, desipramine pharmacology, housing, animal, immobilization, stress drug therapy, antidepressive agents, tricyclic therapeutic use, desipramine therapeutic use, mice.
Kawakami, K., T. Takeuchi, S. Yamaguchi, A. Ago, M. Nomura, T. Gonda, and S. Komemushi (2003). Preference of guinea pigs for bedding materials: wood shavings versus paper cutting sheet. Experimental Animals (Tokyo) 52(1): 11-5. ISSN: 1341-1357.
Abstract: The preference of guinea pigs for bedding materials, wood shavings (WS) or paper cutting sheets (PS), was studied. Animals aged 8 weeks and 20 weeks showed a similar behaviour pattern during 30 min in the light, preferring WS to PS regardless of ages. Over both light and dark periods for 24 h, guinea pigs apparently preferred WS in the light, spending much more time resting in them than in PS. In the dark, the border-crossing was significantly more frequent than in the light, and the staying time was rather longer in PS than WS. The results suggest that guinea pigs prefer different bedding materials under light and dark conditions.
Descriptors: guinea pigs, housing, bedding materials, paper, wood, preference darkness, light.
Korz, V. and R. Gattermann (1999). Housing conditions affect susceptibility to mercury in the golden hamster. Laboratory Animals 33(3): 228-233. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Individually-housed and group-housed golden hamsters (Mesocricetus auratus), aged 8 weeks, were studied with regard to their susceptibility to a single gavage of mercuric chloride (10 mg/kg body weight). Body weight and food consumption were measured for 10 days (day-9 to day 0) in a pre-application period and for 13 days (day 1 to day 13) in a post-application period. Mercuric chloride administration significantly reduced body weight gain in both isolated and grouped hamsters at day 1 compared to vehicle controls. While the individually-housed treated hamsters recovered during the post-application period, the group-housed treated hamsters showed a reduced body weight gain over the whole post-application period. Results are discussed in relation to elevated susceptibility to intoxication in group-housed hamsters triggered by high social stress. This study highlights the need to carefully consider the housing conditions which can influence the results of teratological experiments.
Descriptors: golden hamsters, mercuric chloride, body weight, liveweight gain, toxicity, susceptibility, stress, cage density, group size, feed intake.
Krohn, T.C. and A.K. Hansen (2002). Carbon dioxide concentrations in unventilated IVC cages. Laboratory Animals 36(2): 209-212. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: The use of individually ventilated cage (IVC) systems has become more common worldwide. The various systems are becoming more and more sealed in order to protect the animals against infections and the staff against allergens; which, however, may lead to problematic CO2 concentrations, if the cages are left unventilated. In this study it is shown that, depending on how tight the cage is and the number of animals housed in each cage, CO2 inside the cage within 2 h will increase to levels of between 2 and 8%.
Descriptors: mice, cages, air flow, duration, carbon dioxide, group size, animal welfare.
Krohn, T.C., A.K. Hansen, and N. Dragsted (2003). The impact of cage ventilation on rats housed in IVC systems. Laboratory Animals 37(2): 85-93. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Today the use of individually ventilated cage systems (IVC systems) is common, especially for housing transgenic rodents. Typically, in each cage a ventilation rate of 40 to 50 air changes per hour is applied, but in some systems even up to 120 air changes per hour is applied. To reach this rate, the air is blown into the cage at a relatively high speed. However, at the animal's level most systems ventilate with an air speed of approximately 0.2 m/s. In the present paper, two studies were conducted, one analysing whether an air speed below 0.2 m/s or just above 0.5 m/s affects the rats, and another study analysing whether air changes of 50, 80 and 120 times per hour affect the rats. In both studies, monitoring of preferences as well as physiological parameters such as heart rate and blood pressure, was used to show the ability of the animals to register the different parameters and to avoid them if possible. Air speeds inside the cage of as high as 0.5 m/s could not be shown to affect the rats, while the number of air changes in each cage should be kept below 80 times per hour to avoid impacts on physiology (heart rate and systolic blood pressure). Also the rats prefer cages with air changes below 80 times per hour if they have the opportunity of choosing, as shown in the preference test.
Descriptors: rats, animal husbandry, ventilation, IVC systems, impact, housing, ventilation methods, air movements, animal welfare, behavior.
Krohn, T.C. and A.K. Hansen (2004). Reduction in the spread of rodent urinary allergens during cage changing by laminar air flow cabins. Reduction in rodent allergens by LAF cabins. Scandinavian Journal of Laboratory Animal Science 31(3): 149-154. ISSN: 0901-3393.
Descriptors: rodent, urinary allergens, cage changes, laminar air flow, spread, reduction, staff protection.
Krohn, T.C. and A.K. Hansen (2002). The application of traditional behavioural and physiological methods for monitoring of the welfare impact of different flooring conditions in rodents. Scandinavian Journal of Laboratory Animal Science 29(2): 79-89. ISSN: 0901-3393.
Descriptors: rodents, flooring conditions, welfare, behavior, rats, mice, environmental impacts, grid housing.
Kuhnen, G. (1998). Reduction of fever by housing in small cages. Laboratory Animals 32(1): 42-45. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Housing conditions influence anatomy, physiology, and behaviour of animals. The aim of this study is to investigate whether the generation of fever, a defence response of the body, is also affected by housing conditions. Golden hamsters (Mesocricetus auratus) were housed in small cages, large cages, or large and enriched cages. After 9 weeks of exposure to their respective environments, the fever response to the administration of lipopolysaccharide (50 micrograms/kg from Salmonella typhosa) was tested. One hundred and twenty experiments in 30 hamsters demonstrated that housing in small cages diminished the fever responses (increase in core temperature and fever index) significantly by approximately 20%, and is likely to be due to a higher stress level. The findings demonstrate that the results of physiological experiments are not only influenced by the experimental design, but also by pre-experimental housing conditions.
Descriptors: golden hamsters, cages, size, enrichment, fever, lipopolysaccharides, Salmonella, stress, body temperature, Salmonella typhosa.
Latham, N. and G. Mason (2004). From house mouse to mouse house: the behavioural biology of free-living Mus musculus and its implications in the laboratory. Applied Animal Behaviour Science 86(3-4): 261-289. ISSN: 0168-1591.
NAL Call Number: QL750.A6
Abstract: Understanding a species' behaviour in natural conditions can give insights into its development, responses and welfare in captivity. Here, we review research and pest control literatures on the free-living house mouse (Mus musculus), analysing its sensory world, developmental processes and behaviour to suggest how laboratory environments might affect mouse welfare, normalcy, test design, and behaviour. Mouse development from foetus to weaning is influenced by prenatal stress and nutrient levels, and post-natal litter size and other factors affecting maternal care, all with lasting effects on adult bodyweight, aggression, activity levels, stress responsiveness and masculinisation. These influences may well be important in the laboratory, for example unwittingly differing between facilities leading to site-differences in phenotype. Murine senses are dominated by olfactory, auditory and tactile cues. Their hearing extends into the ultrasonic, and vision, from mid-range wavelengths to the ultraviolet. In mouse facilities, behaviour and welfare may therefore also be affected by sensory stimuli unnoticed by humans. The physical and social environment and behaviour of wild mice differ greatly from those of laboratory mice. Dispersal age varies with resource-levels and social cues, and mice often either live alone or in family groups. Mice occupy territories/ranges measuring a few square meters to several square kilometers, and which allow running, climbing, and burrowing. Mice are often active during dawn/dusk, and spend their time patrolling their territories, investigating neighbours' odour cues, foraging, finding mates and rearing litters. The potential impact of these many differences and restrictions on laboratory mouse development, normalcy and welfare has only begun to be explored.
Descriptors: mouse, behavior, natural conditions, welfare, free living, stress, biology, laboratory, captivity.
Levine, S. and A. Saltzman (1999). Effects of coprophagy on serum urea and the weight of the gastrointestinal tract of fed or fasted rats. Laboratory Animals 33(3): 265-268. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Coprophagy can be minimized by fitting rat cages with metal grids which allow faecal pellets to pass through to the floor of the cage. When bedding was omitted overnight, the extent of coprophagy could be estimated from the weight of the droppings on the cage floor or the weight of the gastrointestinal (GI) tract removed from rats housed with or without grids. The effect of coprophagy was also demonstrated by the elevation of serum urea nitrogen in rats that consumed faeces. Therefore, precautions against coprophagy, or their absence, should be specified in all experimental protocols and reports.
Descriptors: rats, coprophagy, cages, floor type, starvation, body weight, urea, blood composition, digestive tract, weight, feces, collection.
Livingston, R.S., L.K. Riley, C.L. Besch Williford, R.R. Hook Jr., and C.L. Franklin (1998). Transmission of Helicobacter hepaticus infection to sentinel mice by contaminated bedding. Laboratory Animal Science 48(3): 291-2893. ISSN: 0023-6764.
NAL Call Number: 410.9 P94
Descriptors: mice, Helicobacter, horizontal transmission, litter, sentinel animals, antibody formation, polymerase chain reaction, blood serum, ELISA.
Luketich, J.D., K.E. Michel, P.G. Curcillo II, D.A. Rigberg, M.E. Weiss, I.D. Feurer, and J.L. Mullen (1998). Automated, eight-cage indirect calorimetry in rats. Nutrition (Burbank) 14(9): 672-7. ISSN: 0899-9007.
Abstract: We have constructed an automated, eight-cage indirect calorimeter (AIC) for the measurement of energy expenditure in rats. We compared the measurements of resting energy expenditure (REE) in rats during a 30-h fast obtained with the AIC with those obtained with a manual indirect calorimetry (MIC) system. There was both a high degree of correlation between the two techniques during the initial 18 h of the fast (r = 0.90, P < 0.05) and strong intertechnique agreement. REE (AIC) decreased during the final 12 h of the 30-h fast (79.6 +/- 2.7-72.0 +/- 4.4 kcal.kg-0.75.d-1 [mean +/- SD, P < 0.01]). REE (MIC) did not show a significant decrease during this part of the fast (79.7 +/- 2.6 - 75.2 +/- 4.7 kcal.kg-0.75.d-1 [P = NS]). During the final 12 h of the fast agreement between the two systems gradually dissipated and correlation was poor (r = 0.375, P < 0.05). The frequency of animal handling necessitated by MIC may have resulted in a stress-induced increase in metabolic work that would mask the animals' adaptive response to starvation. This investigation demonstrates the advantages of the AIC and calls into question the accuracy of manual methods under long-term starvation conditions.
Descriptors: rats, calorimetry, indirect, energy metabolism, eight cage, automated, exertion, fasting physiology.
Manser, C.E., D.M. Broom, P. Overend, and T.H. Morris (1998). Operant studies to determine the strength of preference in laboratory rats for nest-boxes and nesting materials. Laboratory Animals 32(1): 36-41. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Previous work has shown that laboratory rats preferred to use nest-boxes and nesting materials rather than empty parts of the cage. In preference tests, they chose opaque or semi-opaque nest-boxes and long strips of soft paper nesting material. Choice tests to demonstrate a preference between nest-boxes and nesting material were not possible because nesting materials were carried into the nest-boxes. Furthermore, preference tests did not show how important these items were to the animals. Accordingly, operant tests were conducted, in which the rats had to lift a weighted door in order to gain access to an empty cage, or one containing a nest-box, nesting material or both items. By progressively increasing the weight of the door in subsequent trials, it was shown that the rats would carry out more work to reach a nest-box, with or without nesting material, than to reach an empty cage.
Descriptors: rats, nests, cages, paper, tests, body weight, weight, preference tests.
Masuda, J., D. Mitsushima, and F. Kimura (2004). Female rats living in small cages respond to restraint stress with both adrenocortical corticosterone release and acetylcholine release in the hippocampus. NeuroScience Letters 358(3): 169-172. ISSN: 0304-3940.
Descriptors: rats, female, stress, restraint, response, adrenocortical corticosterone, acetylcholine, hippocampus, small cages.
Matthews, D.A., N.A. Parkins, M. Underwood, and R.M. Santer (1997). Establishing and maintaining a colony of aged male Wistar rats. Animal Technology 48(2): 75-82. ISSN: 0264-4754.
NAL Call Number: QL55.I5
Descriptors: laboratory animals, rats, breeding methods, health, husbandry, maintaining, colony, aged, Wistar rats.
McGlone, J.J., D.L. Anderson, and R.L. Norman (2001). Floor space needs for laboratory mice: BALB/cJ males or females in solid-bottom cages with bedding. Contemporary Topics in Laboratory Animal Science 40(3): 21-5. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Abstract: Studies were initiated to determine the effects of restricted (32.2 cm2 per mouse), normal (96.8 cm2), or excess floor space (129.0 cm2) allowances by using a model of three mice per cage. BALB/cJ mice were bred on-site and weaned at 3 weeks of age into specially designed polycarbonate shoebox cages modified to each space allowance. Cages contained aspen shavings for bedding, and mice were fed and watered ad libitum. Body weight gains, feed and water use, and immunologic measures largely were not effected by floor space allowances. Female BALB/cJ mice were heavier and had increased lymphocyte blastogenesis to phytohemagglutinin (20 microg/mL) when given 32.2 cm2/mouse than when given 129 cm2/mouse. Female mice showed an increase in grooming and sitting behaviors when given 32.2 cm2/mouse, but male mice with restricted floor space spent more time lying down but showed no change in grooming or sitting behaviors compared to mice given more space. Among male mice, limited floor space did not significantly influence growth rates, but male mice given 32.2 cm2/mouse had less mortality than did mice given more space. We conclude that floor spaces as limited as 32.2 cm2/mouse did not cause behavior, health, immune or performance problems for BALB/cJ mice.
Descriptors: mice, male, female, floor space, bedding, solid bottom cages, space, restricted, normal, excess, effects.
Memarzadeh, F., P.C. Harrison, G.L. Riskowski, and T. Henze (2004). Comparison of environment and mice in static and mechanically ventilated isolator cages with different air velocities and ventilation designs. Contemporary Topics in Laboratory Animal Science 43(1): 7, 14-20. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Abstract: The purpose of this study was to compare environmental conditions and mice in cages with four different mechanical ventilation designs and a static isolator cage. Environmental conditions (air velocity, temperature, relative humidity, bedding weight change, airborne dust, NH3, and CO2) were compared for each cage type (n = 5 per cage). Bedding type was chipped hardwood. Mouse response in each cage type was evaluated by body weight, feed consumption, water intake, location of specific behaviors, and building of bedding mounds. Commercial polycarbonate mouse caging units (29.2 x 19.1 x 12.7 cm shoebox style, stainless-steel round wire bar lids, and 7-cm-deep isolator cage filter tops) were modified to fit the mechanical ventilation cage types and were used for the static isolator cages. Mechanically ventilated cages were fitted with forced air inlets centered 5 cm above the cage floor on the 19.1 cm-side of the cage. Inlet air velocity was either 40 or 200 feet/min (n = 10 cages each), and the air volume exchange rate was 9.3 L/min. In half of the mechanically ventilated cages, the exhaust air was forced through a filter in the isolator cage top, whereas in the remaining mechanically ventilated cages, the air was forced through a single exhaust port fixed in the narrow side of the cage top directly above the air inlet. Inlet air velocity but not exhaust design affected intracage air velocity distribution. Other environmental conditions were similar between the four mechanical ventilation designs. Relative to the mechanically ventilated cages, the static isolator cages had lower air velocities, higher relative humidities, higher NH3 levels, higher CO2 levels, lower body weight gain, and lower water consumption; temperatures, particulate levels, and feed consumption rates did not differ significantly between cage types. Locations of bedding mounds and behaviors were similar in all cage treatments.
Descriptors: mice, animal husbandry, caging, ventilation, static, mechanical, laboratory housing, eating, nesting behavior, temperature.
Notes: Comment.
Metzger, M.E. and M.K. Rust (2001). Laboratory techniques for rearing the fleas (Siphonaptera: Ceratophyllidae and Pulicidae) of California ground squirrels (Rodentia: Sciuridae) using a novel nest box. Journal of Medical Entomology 38(3): 465-70. ISSN: 0022-2585.
Abstract: Three species of fleas, Oropsylla montana (Baker), Hoplopsyllus anomalus (Baker), and Echidnophaga gallinacea (Westwood), occur seasonally on the California ground squirrel, Spermophilus beecheyi (Richardson). Few studies have focused on the biology and ecology of these fleas despite their importance in the epidemiology of sylvatic plague. To best duplicate a natural parasite-host relationship in the laboratory, a novel nest box was developed that facilitated housing wild-caught S. beecheyi, was conducive to rearing fleas, and met modern standards for laboratory animal hygiene. This flexible system allowed adult fleas with different feeding strategies to be colonized successfully while providing sufficient flea eggs for both colony maintenance and biological research. The techniques described could be adapted to work with other species of rodents and their fleas.
Descriptors: ground squirrels, fleas growth and development, techniques for rearing, nest box, biology, ecology feeding strategies.
Moragrega, I., M.C. Carrasco, P. Vicens, and R. Redolat (2003). Spatial learning in male mice with different levels of aggressiveness: effects of housing conditions and nicotine administration. Behavioural Brain Research 147(1-2): 1-8. ISSN: 0166-4328.
Abstract: The main aim of the present investigation was to evaluate the possible modulation of spatial learning ability by housing conditions and level of aggressiveness in mice, also testing whether differences in locomotion and anxiety could influence this relationship. Additionally, we have examined effects of nicotine in the acquisition and retention of a spatial learning task in groups of mice differing in these variables. NMRI male mice were either group-housed or individually housed for 30 days and then classified into mice with short (SAL) and long (LAL) attack latency after a pre-screening agonistic encounter. Locomotor activity and baseline levels of anxiety of these groups were evaluated in the actimeter and elevated plus-maze. Results indicated that SAL and LAL individually housed mice displayed higher locomotion activity than LAL group-housed mice. In the plus-maze test, SAL and LAL individually housed mice showed more total and open arm entries than group-housed LAL mice, confirming the hyperactivity of individually housed mice and suggesting that isolation had no clear anxiolytic or anxiogenic actions. In the water-maze, we compared the performance of individually housed SAL, individually housed LAL mice, and group-housed LAL mice treated with nicotine (0.35 and 0.175mg/kg) or vehicle. Nicotine did not improve acquisition in group-housed mice and even impaired it in individually housed mice. Retention of platform position was better in vehicle-treated individually housed mice in comparison with vehicle-treated group-housed mice. The present study demonstrates that housing conditions but not level of aggressiveness modify spontaneous locomotor activity and behaviors displayed on the elevated plus-maze test, and can also influence retention of a spatial learning task.
Descriptors: mice, spatial learning, housing conditions, aggressiveness, anxiety, nicotine, effect.
Morrell, J.M. (1999). Techniques of embryo transfer and facility decontamination used to improve the health and welfare of transgenic mice. Laboratory Animals 33(3): 201-206. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: 'Reduction' and Refinement' can be achieved in transgenic mouse studies by re-deriving transgenic mouse lines and subsequently maintaining them under high standards of husbandry in a unit with restricted access. This report describes the initial steps of a project to improve the health and welfare of transgenic mice at the European Molecular Biology Laboratory (EMBL), by re-deriving transgenic lines as microbiologically defined animals to be maintained in a barrier unit in a newly constructed animal facility. A pilot study showed that it was possible to transfer embryos obtained from contaminated donor mice in the old facility to specific pathogen free recipients housed in a ventilated cabinet in the new unit, without concomitant carry over of disease. The offspring born following embryo transfer were of high health status and did not show any evidence of contamination with any of the pathogens present in the mice in the old animal unit. Antibodies to various murine viruses (mouse hepatitis virus (MHV), rota virus, reo-3 virus, Theilers encephalomyelitis virus, adenovirus) and parasites were present in sentinel animals from the old animal house whereas the re-derived animals were found to be free of virus antibodies and parasites. Therefore the methods used were considered to be successful in terms of disease prevention and enhancement of welfare. The barrier unit was sterilized without the use of formaldehyde or related substances, to minimize the risks to personnel and to the environment from using potentially dangerous substances. From the results of in vitro and in vivo screening, the protocol for sterilization described here was found to be effective in achieving. microbiological sterility of the barrier unit and was cost effective.
Descriptors: mice, transgenic animals, barrier husbandry, embryo transfer, livestock numbers, animal experiments, sterilants, nematicides, benzalkonium chloride, microbial contamination.
Morrison, J.C., W.O. Cepurna, E.C. Johnson, V. Ackhavong, and L. Jia (2000). Loss of optic nerve axons in aged rats following chronic intraocular pressure (IOP) elevation due to constant light housing. IOVS 41(4): S896.
Descriptors: rats, optic nerve axons, intraocular pressure, elevation, constant light, meeting abstract.
Notes: Meeting Information: Annual Meeting of the Association for Research in Vision and Ophthalmology, April 30-May 05, 2000, Fort Lauderdale, Florida, USA.
Myers, D.D., E. Smith, I. Schweitzer, J.D. Stockwell, B.J. Paigen, R. Bates, J. Palmer, and A.L. Smith (2003). Assessing the risk of transmission of three infectious agents among mice housed in a negatively pressurized caging system. Contemporary Topics in Laboratory Animal Science 42(6): 16-21. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Abstract: Previous studies from our institution have shown that ventilated caging run at negative pressure to a mouse room dramatically reduced exposure of personnel to the major mouse allergen, Mus m 1. The current study was designed to determine whether negative cage ventilation posed an inordinate risk for spread of infectious agents between cages and/or racks. B6;129S-Tnfsf5(tm1Imx)/J (TNF) mice, which were naturally and persistently infected with Pneumocystis carinii, Helicobacter bilis, and Pasteurella pneumotropica, were used as the source of infections. Uninfected C3Smn.CB17-Prkdc(scid)/J (SCID) mice with severe combined immunodeficiency were used to detect transmission. The following methods were used to detect transmission of infections: polymerase chain reaction (PCR) amplification and histological examination of lungs for P. carinii; PCR of fecal specimens or cecal contents for H. bilis; and culture of oropharyngeal, tracheal, or vaginal swabs for P. pneumotropica. We determined whether transmission of the three agents occurred via direct contact (cohabitation), exposure to soiled bedding, and/or by handling naive SCID mice after handling infected TNF mice. During a 12-week period, all three infectious agents were readily transmitted to uninfected mice by cohabitation. Transmission was much less efficient and occurred later among mice exposed to contaminated bedding. Transmission did not occur as a result of handling. We then studied transmission of the three infectious agents among mice housed in individually ventilated cages run at negative pressure in a small, crowded mouse room. Transmission of P. carinii was detected at the end of the 12-month study in the densely populated room, probably because the exhaust from the changing station passed over soiled cages and caused aerosolization of particulates. Caging systems run at negative pressure effectively reduce personnel exposure to allergens and may also inhibit the transmission of infectious diseases.
Descriptors: mice, housing, infection, transmission, negative pressure, risk, control, exposure, ventilation.
Nagy, T.R., D. Krzywanski, J. Li, S. Meleth, and R. Desmond (2002). Effect of group vs. single housing on phenotypic variance in C57BL/6J mice. Obesity Research 10(5): 412-415. ISSN: 1071-7323.
NAL Call Number: RC628.O294
Descriptors: body composition, phenotypic variation, phenotypes, genotypes, environmental factors, animal housing, body fat, body lean mass, inbred mice strains, group housing.
Novak, G. (1997). Individually ventilated microisolation cages. Lab Animal 26(8): 54-57. ISSN: 0093-7355.
NAL Call Number: QL55.A1L33
Descriptors: cages, ventilation, air flow, transgenic animals, mice.
Olsson, I.A.S., C.M. Nevison, E.G. Patterson Kane, C.M. Sherwin, H.A. Van de Weerd, and H. Wurbel (2003). Understanding behaviour: the relevance of ethological approaches in laboratory animal science. Applied Animal Behaviour Science 81(3): 245-264. ISSN: 0168-1591.
NAL Call Number: QL750.A6
Descriptors: mice, rats, laboratory animals, animal behavior, strain differences, animal housing, cages, environmental enrichment, smell, vision, hearing, taste, touch, validity.
Olsson, I.A.S., S. Olsson, and K. Dahlborn (2002). Improving housing conditions for laboratory mice: a review of 'environmental enrichment'. Laboratory Animals 36(3): 243-270. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Laboratory animal facilities have been designed to provide a standard environment where animals can be kept in good physical health at the same time as economic and ergonomic considerations are met. Recognizing the potential welfare problem associated with behavioural restriction in such housing systems, a number of attempts have been made to improve this environment, generally described under the term 'environmental enrichment'. Modifications of cages for mice usually consist of providing material for nest building and structures which can serve as hiding places and/or for climbing. We have reviewed 40 studies carried out between 1987 and 2000, in which preferences as well as the effect of housing modifications have been studied. Mice will work for access to nesting material and make use of this material to make nests in which they rest. They prefer a more complex cage to the standard cage and will also work for access to cages with shelter and raised platforms. On the basis of present knowledge, it is recommended that mice should have access to nesting material. Strategies for future research are outlined in the article.
Descriptors: mice, laboratory mammals, enrichment, animal welfare, nesting, stress, cages, design, litter, animal behavior, male animals, aggressive behavior, territoriality, strain differences, literature reviews, animal stress, animal use refinement.
Otto, G. and R.J. Tolwani (2002). Use of microisolator caging in a risk-based mouse import and quarantine program: a retrospective study. Contemporary Topics in Laboratory Animal Science 41(1): 20-27. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: mice, laboratory mammals, quarantine, sentinel animals, mutants, cages, inbred strains, animal health, risk assessment, murine hepatitis virus, murine encephalomyelitis virus, Pasteurella, mites, syphacia, cost control.
Ouagazzal, A.M., J.L. Moreau, M. Pauly Evers, and F. Jenck (2003). Impact of environmental housing conditions on the emotional responses of mice deficient for nociceptin/orphanin FQ peptide precursor gene. Behavioural Brain Research 144(1-2): 111-7. ISSN: 0166-4328.
Abstract: Nociceptin/orphanin FQ (N/OFQ) is a newly discovered neuropeptide that has been implicated in the neurobiological regulation of the behavioral responses to stress and fear. To investigate the role of this peptide in the expression of stress/anxiety-related behaviors in mice, a gene targeting approach to disrupt N/OFQ in the pre-proN/OFQ gene was used. The impact of environmental housing conditions (single and social housing) was assessed on N/OFQ-knockout male and female mice in different experimental paradigms known to trigger distinctive types of stress and anxiety states. Neurological examination of homozygous mutant adult animals indicated that basic neurological functions (vision, audition, olfaction, tactile and pain sensitivity, motor performances) were normal. When housed individually, N/OFQ-knockout animals displayed responses similar to control animals in behavioral tests of emotional reactivity (behavioral despair, locomotor activity, light-dark preference, and acoustic startle tests). In contrast, increased emotional responses were detected when individually housed mice were crowded together (five per cage) under conditions of competitive access to food, water, space, and social contacts. Under those conditions, male mice deficient for N/OFQ developed greater home-cage aggression and increased fear/anxiety-like behaviors in the light-dark and acoustic startle tests, when compared to their wild-type littermates. Group-housed female mutants also showed higher level of anxiety in the acoustic startle test, but needed additional restrain stress to express detectable levels of anxiety in the light-dark test. These data indicate a clear environment-induced rise in fear reactions of N/OFQ-knockout mice. They further suggest that N/OFQ system is essential for development of adequate coping strategies to acute and chronic stress.
Descriptors: mice, environment, housing, conditions, impact, emotional responses, behavior, nociception orphanin, physiology, rats.
Pachowsky, U. (1999). Der Einfluss der Haltungsstandardisierung auf physiologische Merkmale bei Mausen. [The influence of the standardization of housing on physiological variants of mice]. Dissertation, Tierarztliche Hochschule Hannover: Hannover. 103 p.
NAL Call Number: DISS F1999303
Descriptors: housing, mice, varients, standardization, influence, physiology.
Language of Text: German.
Notes: Thesis (doctoral).
Patterson Kane, E.G. (2002). Cage size preference in rats in the laboratory. Journal of Applied Animal Welfare Science 5(1): 63-72. ISSN: 1088-8705.
NAL Call Number: HV4701.J68
Descriptors: rats, laboratory animals, cage size, animal behavior, group size, animal welfare, animal preferences, group housing.
Peace, T.A., A.W. Singer, N.A. Niemuth, and M.E. Shaw (2001). Effects of caging type and animal source on the development of foot lesions in Sprague Dawley rats (Rattus norvegicus). Contemporary Topics in Laboratory Animal Science 40(5): 17-21. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: rats, laboratory mammals, cages, floor type, feet, lesions, wire netting, floors, body weight, sex differences, strain differences, age differences, ulcers, edema, nontarget effects, animal welfare, solid floors.
Perez, C., J.R. Canal, E. Dominguez, J.E. Campillo, M. Guillen, and M.D. Torres (1997). Individual housing influences certain biochemical parameters in the rat. Laboratory Animals 31(4): 357-361. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Individual housing has been reported to modify animal behaviour. The present study compares the plasma levels of glucose, triglycerides and total cholesterol, weight, and food and water intake in two groups of female rats. Group A: 10 rats who remained grouped in two cages for 21 days; and Group B: 10 rats housed in two cages for 7 days, then isolated in individual cages from day 8 to day 15, and finally grouped together again for the last 7 days of the study. The results showed that the plasma values of glucose declined (P<0.05) in the Group B rats when they had been returned to group condition (4.79 +/- 0.72 mM) than when they had been isolated (5.45 +/- 0.94 mM). Plasma triglyceride levels were lower (P<0.05) in isolated rats (0.70 +/- 0.26 mM) than in any determination of the grouped rats. Group B: 1st week 1.21 +/- 0.21 mM, 3rd week 0.88 +/- 0.20 mM; and Group A: 1.22 +/- 0.20, 0.96 +/- 0.16, and 0.96 +/- 0.36 mM, in the first, second, and third week, respectively. There were no statistically significant differences in total cholesterol values as a function of the individual housing of animals. While there was no weight difference between the two groups of rats that could be ascribed to individual housing, there was a statistically significant increase (P<0.05) in the food intake of isolated rats 117.5 +/- 3.2 g) with respect to values in the same Group B animals when they were housed together (1st week, 16.6 +/- 2.8 g; 3rd week, 16.8 +/- 3.1 g). These results therefore confirm that individual housing of female rats provoke variations in certain biochemical parameters, and that if this is not taken into account in performing different scientific studies, it could give rise to unreliable or even. dubious results.
Descriptors: rats, animal housing, animal behavior, blood plasma, blood sugar, blood lipids, triacylglycerols, feed intake, water intake.
Pham, T.M. and V. Baumans (2004). Impact of group housing on post-operative recovery in mice. Animal Welfare 13, Supplement: S253. ISSN: 0962-7286.
NAL Call Number: HV4701.A557
Descriptors: mice, group housing, impact, post operative recovery, impact, animal welfare, behavior, cage enrichment.
Notes: Meeting Information: Universities Federation for Animal Welfare (UFAW) Symposium on Science in the Service of Animal Welfare, Animal Welfare, Edinburgh, UK, April 02-04, 2003.
Raje, S.S. and K.L. Stewart (2000). Group housing female guinea pigs. Lab Animal 29(8): 31-32. ISSN: 0093-7355.
NAL Call Number: QL55.A1L33
Descriptors: guinea pigs, female animals, group size, group housing, cages, space requirements, enrichment, behavior, husbandry, animal welfare.
Rao, G.N. and P.W. Crockett (2003). Effect of diet and housing on growth, body weight, survival and tumor incidences of B6C3F1 mice in chronic studies. Toxicologic Pathology 31(2): 243-50. ISSN: 0192-6233.
Abstract: Diet is one of the most important environmental factors influencing growth, body weight, survival, and age-related diseases of rodents in chronic studies. NIH-07 open formula diet was the selected diet for the NTP studies from 1980 to 1994. A new diet designated as NTP-2000 diet is the current diet for mice in the NTP studies beginning in 1994. This report is a summary of results of untreated control groups of B6C3F1 mice fed NTP-2000 or NIH-07 diet from several retrospective 2-year dosed-feed and inhalation studies for differences in growth, body weight, survival, and tumor incidences. The dosed-feed studies were conducted in 3 different facilities located in the United States, and all the inhalation studies were conducted in 1 facility. During dosed-feed studies, male and female mice housed in polycarbonate cages and fed the NTP-2000 diet had lower maximum body weights than those fed NIH-07 diet. However, during inhalation studies, mice housed in wire mesh cages and fed the NTP-2000 diet had higher maximum body weights than the mice fed NIH-07 diet. Survival was higher in groups fed NTP-2000 diet irrespective of sex, housing conditions, or body weight compared to the corresponding groups fed NIH-07 diet. Survival was higher in mice housed in polycarbonate cages irrespective of diet and sex compared to the respective sex and diet groups housed in wire mesh cages. During inhalation studies, survival of male and female mice fed NTP-2000 diet was higher than that of the groups fed NIH-07 diet, although the body weights of NTP-2000 diet groups were higher than those of the groups fed NIH-07 diet. When the NTP-2000 diet was used, male and female mice in dosed-feed studies and male mice in inhalation studies had markedly lower incidences of liver tumors than the corresponding groups fed NIH-07 diet. Significant decreases in the incidences of lung tumors were observed only in the male groups fed NTP-2000 diet during dosed-feed studies. These results suggest that body weight may not be the major contributing factor for mortality and liver tumors and that an interaction between diet and housing conditions appears to affect the growth, survival and tumor incidences of B6C3F1 mice.
Descriptors: animal feed, body weight physiology, diet, animal housing, neoplasms mortality, toxicity tests, chronic methods, carcinogenicity tests, food, formulated, mice, inbred mice strains, specific pathogen free organisms, survival rate.
Ras, T., M. Van de Ven, E.G. Patterson Kane, and K. Nelson (2002). Rats' preferences for corn versus wood-based bedding and nesting materials. Laboratory Animals 36(4): 420-5. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Corn by-products can be used as bedding and nesting products. Corn-cob bedding resists ammonia build-up and corn-husk nesting material resists dampness. It is not clear whether these advantages are at the expense of animal comfort. Corn cob was compared to aspen chip bedding, and corn husk to paper strip nesting material. Data from 20 rats with differential early bedding experience suggested that they prefer aspen chip, but are also biased towards the bedding they were raised on. Data from 10 rats with no prior nesting material experience suggested that paper strip was preferred over cornhusk. Thus, corn-cob products are not recommended except in situations where air quality and/or flooding are significant problems.
Descriptors: rats, nesting materials, corn, wood, preferences, husbandry, bedding, behavior.
Renstrom, A., G. Bjoring, and A.U. Hoglund (2001). Evaluation of individually ventilated cage systems for laboratory rodents: occupational health aspects. Laboratory Animals 35(1): 42-50. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: New ventilated caging systems for laboratory animals were compared with conventional caging regarding allergen distribution, ergonomic suitability, cage environment and animal welfare. This paper presents occupational health evaluations. Mice were placed in individually ventilated cage (IVC) systems, a ventilated cabinet, and in cages on open shelves (conventional husbandry). The IVC systems were studied at negative and positive airflow. Aeroallergens were sampled on filters (n=204, including controls) in undisturbed rooms and during cage changing. Concentrations of mouse urinary allergen (Mus m 1) in filter eluates were measured using sandwich ELISA. An ergonomic evaluation was performed with measurement of traction forces. Staff exposure during cage changing was high in all systems, range 116-4430 ng Mus m 1/m(3). In undisturbed animal rooms, allergen levels were orders of magnitude higher when using conventional caging compared with ventilated systems; P < 0.001. At positive pressure, both IVCs leaked allergen (median Mus m 1 concentration was < 0.08 ng/m(3) at negative, but 6.5 ng/m(3) (IVC 1) and 0.8 ng/m(3) (IVC2S) at positive pressure). The IVC systems had ergonomic disadvantages compared with the conventional husbandry and the ventilated cabinet, for instance with cages in unsuitable working heights. Ventilated husbandry solutions reduce levels of airborne allergen substantially at negative pressure, but are ergonomically less suitable. To prevent allergen exposure during cage changing, we propose that this procedure should be performed under ventilated conditions. Producers and users must cooperate in optimizing animal caging systems for both animals and. staff.
Descriptors: mice, rodents, cages, design, artificial ventilation, husbandry, allergens, occupational hazards, ventilated cage system, welfare, safety at work, ergonomics.
Robinson, I., T. Dowdall, and T.F. Meert (2004). Development of neuropathic pain is affected by bedding texture in two models of peripheral nerve injury in rats. NeuroScience Letters 368(1): 107-111. ISSN: 0304-3940.
Descriptors: rats, neuropathic pain, nerve injury, models, bedding texture, chemical hypersensitivity, mechanical hyperalgesia.
Rock, F.M., M.S. Landi, H.C. Hughes, and R.C. Gagnon (1997). Effects of caging type and group size on selected physiologic variables in rats. Contemporary Topics in Laboratory Animal Science 36(2): 69-72. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: rats, cages, group size, effects, housing, behavior, physiological variables, motor activity.
Royals, M.A., D.M. Getzy, and S. Vandewoude (1999). High fungal spore load in corncob bedding associated with fungal-induced rhinitis in two rats. Contemporary Topics in Laboratory Animal Science 38(1): 64-66. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: rats, rhinitis, maize cobs, litter, autoclaving, fungal spores, Aspergillus, Cladosporium, Acremonium, Penicillium, Fusarium, Basidiomycotina, case reports.
Sanford, A.N., S.E. Clark, G. Talham, M.G. Sidelsky, and S.E. Coffin (2002). Influence of bedding type on mucosal immune responses. Comparative Medicine 52(5): 429-432. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: The mucosal immune system interacts with the external environment. In the study reported here, we found that bedding materials can influence the intestinal immune responses of mice. We observed that mice housed on wood, compared with cotton bedding, had increased numbers of Peyer's patches (PP) visible under a dissecting microscope. In addition, culture of lymphoid organs revealed increased production of total and virus-specific IgA by PP and mesenteric lymph node (MLN) lymphocytes from mice housed on wood, compared with cotton bedding. However, bedding type did not influence serum virus-specific antibody responses. These observations indicate that bedding type influences the intestinal immune system and suggest that this issue should be considered by mucosal immunologists and personnel at animal care facilities.
Descriptors: mice, wood chips, cotton, immune response, Peyer's patches, Rotavirus, lymph nodes, small intestine, immunoglobulin A, immunoglobulin G, lamina propria.
Schridde, U. and G. Van Luijtelaar (2005). The role of the environment on the development of spike-wave discharges in two strains of rats. Physiology and Behavior 84(3): 379-386. ISSN: 0031-9384.
Abstract: Recently, we demonstrated that Type 1 and 2 spike-wave discharges (SWD) in the EEG of juvenile WAG/Rij rats were affected differently by housing before the period at which SWD start to occur. Here we consider possible sensitive periods by analyzing strain and housing influences before and after age of SWD onset. The effects of environment in WAG/Rij and ACI rats were investigated by manipulating housing during the period in which SWD become fully manifested in WAG/Rij rats. Rats were first housed from weaning in either an impoverished or enriched environment. Housing changed for half of the rats at three months, while for the other half housing stayed the same. EEG recordings at six months showed that enriched housing led to a worsening of seizure activity. The occurrence, number and mean duration of both types of discharges were influenced differently by strain, housing and age. Our data strengthen the strong genetic dependence of Type 1 SWD, but the mean duration seems to remain sensitive to housing during development. Type 2 SWD are more sensitive to environmental influences, especially in WAG/Rij rats. Moreover, the period after three months seems a sensitive period for housing effects on Type 2 SWD in this strain. Finally, our data further support the idea that Type 1 and 2 SWD are different phenomena, with their number and mean duration controlled by distinct mechanisms.
Descriptors: environment, spike waves, role, development, rats, strains, housing, influences.
Schridde, U. and G. Van Luijtelaar (2004). The influence of strain and housing on two types of spike-wave discharges in rats. Genes Brain and Behavior 3(1): 1-7. ISSN: 1601-1848.
Descriptors: rats, strain, housing, influence, spikewave discharges, epilepsy, convulsive seizures, enriched environment, housing influence.
Schwarting, R.K.W. and C.R. Pawlak (2003). Individual differences of pre-weaning ultrasound vocalization and effects of transient post-weaning housing in isolation on plus-maze and open field behavior in adult Wistar rats. Society for NeuroScience Abstract Viewer and Itinerary Planner: Abstract No. 837.5.
Online: http://sfn.scholarone.com
Descriptors: rats, weaning housing, isolation, open field, behavior, individual differences, ultrasound vocalization.
Notes: Meeting Information: 33rd Annual Meeting of the Society of Neuroscience, November 08-12, 2003, New Orleans, LA, USA.
Sherwin, C.M. (2004). The influences of standard laboratory cages on rodents and the validity of research data. Animal Welfare 13(Supplement): S9-15. ISSN: 0962-7286.
NAL Call Number: HV4701.A557
Descriptors: rodents, cage influence, husbandry, welfare, cages, stress, research data.
Sherwin, C.M. (1996). Preferences of individually housed TO strain laboratory mice for loose substrate or tubes for sleeping. Lab Animal 30(3): 245-251. ISSN: 0093-7355.
NAL Call Number: QL55.A1L33
Descriptors: laboratory animals, behavior, animal welfare, TO mice, sleeping, tubes, animal housing, loose substrate, preferences.
Sherwin, C.M. (2004). The motivation of group-housed laboratory mice, Mus musculus, for additional space. Animal Behaviour 67(4): 711-717. ISSN: 0003-3472.
NAL Call Number: 410 B77
Abstract: The limited amount of space that we provide for research animals can adversely influence the validity of behavioural data and animal welfare. Consumer demand studies have examined the strength of motivation that animals have for additional space; however, one problem of these studies is that the animals tested were generally of a gregarious species, but were tested in isolation. I trained a single mouse from each of six groups to perform an operant task to gain access to an additional 319, 777, or 1600cm super(2) while group-housed. As the cost of visits increased, the mice continued to gain access to the additional space, although the numbers of visits and the time in the additional space decreased. The slopes of the demand functions for the three amounts of additional space ranged between 0.64 and 0.44, indicating that the mice perceived additional space to be an important resource. The slopes of the demand functions, the areas under the demand functions and the Y-axis intercepts were not significantly different between the three sizes of additional space, thus corroborating previous similar work. These results indicate that group-housed laboratory mice in standard laboratory cages were highly motivated for additional space, but did not discriminate between the amounts offered.
Descriptors: mice, motivation, additional space, behavior, isolation, welfare, animal care, cage, space, group housing, single housing.
Sherwin, C.M. and E.F. Glen (2003). Cage colour preferences and effects of home cage colour on anxiety in laboratory mice. Animal Behaviour 66(6): 1085-1092. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: mice, behavior, cage color, effects, preferences, anxiety, sensory reception, color vision, home cage.
Sherwin, C.M. and I.A.S. Olsson (2004). Housing conditions affect self-administration of anxiolytic by laboratory mice. Animal Welfare 13(1): 33-38. ISSN: 0962-7286.
NAL Call Number: HV4701.A557
Abstract: Tests of emotionality conducted outside the home-cage show that rodents from standard laboratory housing are more anxious than animals from enriched housing; however, it is not known if this also indicates increased anxiety within the home-cage. We used a novel method, recording the self-administration of a psychoactive anxiolytic, to examine home-cage anxiety levels of laboratory mice (three per cage) in Standard (n = 10 cages), Unpredictable (n = 10 cages) and Enriched (n = 6 cages) housing. The mice were given a choice of drinking either non-drugged water or a solution of the benzodiazepine Midazolam. There was a significant effect of housing on the proportion of total fluid consumed from the bottle containing Midazolam solution (P = 0.02). Mice from Standard and Unpredictable cages drank a greater proportion than mice from Enriched cages. This indicates that mice from the Standard and Unpredictable laboratory caging may have been experiencing greater anxiety than mice from the Enriched cages. There was also a significant effect of bottle position (P = 0.002). Mice from the Standard and Unpredictable cages drank a greater proportion of total fluid from the bottle containing Midazolam solution when this was toward the rear of the cage rack, ie in a location that was less susceptible to extraneous disturbance. Monitoring self-administration of psychoactive drugs as a method of welfare assessment could be applied to a wide variety of housing conditions, husbandry practices, or experimental procedures that putatively induce negative mental states. The major finding is that standard cages for laboratory rodents may induce greater anxiety than enriched cages. This is discussed in terms of animal welfare and the validity of data from animals housed in minimalistic environments.
Descriptors: mice, housing conditions, self administration, behavior, anxiety, anxiolytic, Midazolam, enrichment, welfare, midazolam, husbandry practices.
Silva, R.C., N.R. Santos, and M.L. Brandao (2003). Influence of housing conditions on the effects of serotonergic drugs on feeding behavior in non-deprived rats. Neuropsychobiology 47(2): 98-101. ISSN: 0302-282X.
Descriptors: rats, non deprived, housing conditions, serotonergic drugs, effects, feeding behavior, serotonin.
Skalicky, M., E. Narath, and A. Viidik (2001). Housing conditions influence the survival and body composition of ageing rats. Experimental Gerontology 36(1): 159-70. ISSN: 0531-5565.
Abstract: Ad libitum fed male Sprague-Dawley rats were randomly assigned to be housed individually (n=32) or four in each cage (n=32) from five to 23 months of age. Body weight and body composition by bioimpedance analysis were monitored longitudinally. An equation for analysis of body composition was developed. Deaths and causes of death were recorded. Of the individually housed animals (H1) 16 percent died, while 44 percent of those housed four in a cage (H4) died, the most common causes of death being circulatory failure, nephritis and tumours of the hypophysis.Body weight increased in both groups over time, significantly more for H4 from 6months of age. Both fat free mass and total body fat increased in both groups over time. Fat in percent of body weight increased up to an age of 14months. H4 animals had significantly more fat from 11 to 20 months of age but lost weight, mostly fat when approaching 23months of age. The occiput-sacrum length of the animals increased up to 11months of age and stayed then constant. Animals in both groups grew also in the cross-sectional dimension. The H1 animals continued to grow all the time, while the growth of the H4 animals stopped at the age of 17 months, when the mortality started to become pronounced.It is concluded that housing conditions can modulate the outcome of the ageing of sedentary and otherwise not treated rats in long-term experiments. Further, the feasibility of monitoring body composition longitudinally with bioimpedance analysis was demonstrated.
Descriptors: rats, aging physiology, body composition, housing conditions, survival, longevity.
Smith, A.L., S.L. Mabus, J.D. Stockwell, and C. Muir (2004). Effects of housing density and cage floor space on C57BL/6J mice. Comparative Medicine 54(6): 656-663. ISSN: 1532-0820.
NAL Call Number: SF77.C65
Abstract: The Guide for the Care and Use of Laboratory Animals (The Guide) is widely accepted as the housing standard by most Institutional Animal Care and Use Committees. The recommendations are based on best professional judgment rather than experimental data. Current efforts are directed toward replacing these guidelines with data-driven, species-appropriate standards. Our studies were undertaken to determine the optimum housing density for C57BL/6J mice, the most commonly used inbred mouse strain. Four-week-old mice were housed for 8 weeks at four densities (the recommended approximately 12 in2 [ca. 77.4 cm2]/mouse down to 5.6 in2 [ca. 36.1 cm2]/mouse) in three cage types with various amounts of floor space. Housing density did not affect a variety of physiologic parameters but did affect certain micro-environmental parameters, although these remained within accepted ranges. A second study was undertaken housing C57BL/6J mice with as little as 3.2 in2/mouse (ca. 20.6 cm2). The major effect was elevated ammonia concentrations that exceeded limits acceptable in the workplace at increased housing densities; however, the nasal passages and eyeballs of the mice remained microscopically normal. On the basis of these results, we conclude that C57BL/6J mice as large as 29 g may be housed with 5.6 in2 of floor space per mouse. This area is approximately half the floor space recommended in the Guide. The role of the Guide is to ensure that laboratory animals are well treated and housed in a species-appropriate manner. Our data suggest that current policies could be altered in order to provide the optimal habitation conditions matched to this species' social needs.
Descriptors: housing, density, cage floor space, mice, effects, The Guide for the Care and Use of Laboratory Animals, C57BL 6J mice, studies.
Smith, D., J. Pedro Botet, I. Cantuti Castelvetri, B. Shukitt Hale, E.J. Schaefer, J. Joseph, and J.M. Ordovas (2001). Influence of photoperiod, laboratory caging and aging on plasma lipid response to an atherogenic diet among F1B hamsters. International Journal of Neuroscience 106(3-4): 185-94. ISSN: 0020-7454.
Abstract: The effects and interactions of photoperiod, animal caging, aging and diet on plasma lipid levels in male F1B hamsters were examined in the current study. Sixteen young and sixteen old animals were housed one or four per cage. Eight young animals from each housing group were placed in an animal room with either 12/12 h (PT-12) or 10/14 h (PT-10) light/dark cycle while the sixteen old animals were maintained under a PT-12 light cycle. Plasma cholesterol and triglyceride concentrations were determined in all animals after a 2-week period of acclimation on chow diet and following 4-week intervention on atherogenic diet. Baseline total cholesterol (TC) levels were 131+/-25 mg/dl and 142+/-39 mg/dl for young and old animals, respectively, while baseline triglyceride (Tg) levels were 202+/-48 mg/dl and 160+/-37 mg/dl respectively for the same animals. Following 4-weeks on an atherogenic diet, single-caged PT 12 animals had elevated but significantly lower TC levels than group-caged animals (161+/-30 mg/dl and 240 +/-58 mg/dl, respectively) while single and group housed PT10 animals had TC levels of 296+/-75 mg/dl and 351+/-124 mg/dl, respectively. Similarly, plasma Tg levels rose to 330+/-100 mg/dl and 486+/-200 mg/dl in single and group housed PT12 animals (respectively) and to 668+/-270 mg/dl and 545+/-199 mg/dl in single and group housed PT10 animals (respectively). No significant changes related to atherogenic diet were observed in plasma TC or Tg levels in the older animals. Although caging conditions influence the cholesterol and triglyceride response to the atherogenic diet (p<.05), light cycle photoperiod seems to exert a greater effect (p<.005). In conclusion, photoperiod length dramatically affects diet-induced plasma lipid concentrations in young male F1B hamsters, and thus needs be considered in experimental designs of animal-housed lipid research.
Descriptors: aging physiology, cholesterol blood, diet, atherogenic, housing, animal, photoperiod, triglycerides blood, hamsters.
Smith, E., J.D. Stockwell, I. Schweitzer, S.H. Langley, and A.L. Smith (2004). Evaluation of cage micro-environment of mice housed on various types of bedding materials. Contemporary Topics in Laboratory Animal Science 43(4): 12-7. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: mice, animal husbandry, environment, bedding materials, micro environment, cage, ammonia levels, ventilation.
Spangenberg, E.M., H. Augustsson, K. Dahlborn, B. Essen Gustavsson, and K. Cvek (2005). Housing-related activity in rats: effects on body weight, urinary corticosterone levels, muscle properties and performance. Laboratory Animals 39(1): 45-57. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: The cage systems commonly used for housing laboratory rats often result in sedentary and overweight animals, as a consequence of restricted opportunities for physical activity combined with ad libitum feeding. This can have implications both for animal well-being and for the experimental outcome. Physical activity has several known positive effects on health and lifespan, and physical fitness might therefore be incorporated into the animal welfare concept. The aim of this study was to investigate if and how pen housing affects the physical activity and fitness of rats. Thirty-two juvenile male Sprague-Dawley rats were randomly assigned to two different housing systems for a 4-week period. Sixteen rats were kept individually in standard Makrolon type III cages (42x26x18 cm) furnished with black plastic tubes (singly-housed, SI). The remaining rats were kept in groups of eight, housed in large floor pens (150x210 cm), which were furnished with various objects to increase environmental complexity (pen-housed, PH). The body weight gain, and food and water intake of the rats were measured. During weeks 3 or 4, home cage behaviour, urinary cortiosterone/creatinine ratios (CO/CR), and muscle strength on an inclined plane, were measured. Enzyme activities and glycogen content were measured in tissue samples from m. triceps brachii taken after euthanization at the end of the study. There were no significant differences between groups for food and water intake, but PH rats weighed 14% less than SI rats after 4 weeks, and PH rats also had a more diverse behavioural pattern than SI rats. PH rats had significantly higher oxidative capacity (28% more citrate synthase (CS)) and greater glycogen content (28%) in their muscle samples than SI rats. The PH rats performed significantly better on the inclined plane, both in the muscle strength test (mean angle 75+/-0.5 degrees for PH rats and 69+/-0.4 degrees for SI rats) and the endurance strength test (mean time 233+/-22 s for PH rats and 73+/-14 s for SI rats). There was a negative correlation between body weight and results on the inclined plane for the PH rats. There were no significant differences between housing types with respect to CO/CR ratios. In conclusion, the large pen represents an environment that stimulates physical activity and more varied behaviour, which should be beneficial for the welfare of the animal.
Descriptors: housing, activities, rats, effects, body weight, muscle properties, urinary corticosterone, performance.
Spani, D., M. Arras, B. Konig, and T. Rulicke (2003). Higher heart rate of laboratory mice housed individually vs in pairs. Laboratory Animals 37(1): 54-62. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Many studies have shown that housing mice individually over a long period significantly alters their physiology, but in most cases measurement has required human interference and restraint for sampling. Using a radio-telemetry system with implantable transmitters, we recorded heart rate (HR), motor activity (ACT) and body temperature (BT) of freely moving male mice (NMRI) housed either individually or in pairs with an ovarectomized female. Data for each parameter were collected at 5 min intervals for two consecutive 24 h periods. Even after several weeks of habituation to the social conditions, HR was increased in mice housed individually compared with mice housed in pairs, although their measured ACT did not differ. Additionally, BT tended to be reduced in individually-housed mice. When the data were analysed according to different ACT levels, HR was increased in individually-housed mice during phases of low and high, but not intermediate, motor activity. Furthermore, individually-housed mice had more, but shorter, resting bouts, indicating disruption of the normal circadian sleep pattern. Enhanced HR in individually-housed mice does not necessarily indicate stress, but might be an important physiological indicator of discomfort. The fact that individual housing alters basic physiological parameters in laboratory mice highlights the need to control for housing-dependent variation, especially in experiments that are sensitive to changes in these parameters.
Descriptors: mice, housing, pairs, individually, heart rate, telemetry, stress, physiological indicator.
Stark, D.M. (2001). Wire-bottom versus solid-bottom rodent caging issues important to scientists and laboratory animal science specialists. Contemporary Topics in Laboratory Animal Science 40(6): 11-14. ISSN: 1060-0558.
NAL Call Number: SF405.5.A23
Descriptors: rats, laboratory mammals, cages, floor type, surveys, cost analysis, litter, hygiene, animal welfare, urine, feces, feet, lesions, labor costs, animal preferences, animal use refinement.
Stefanski, V., G. Knopf, and S. Schulz (2001). Long-term colony housing in Long Evans rats: immunological, hormonal, and behavioral consequences. Journal of Neuroimmunology 114(1-2): 122-30. ISSN: 0165-5728.
Abstract: The distribution pattern and the function of blood immune cells were investigated for 10 weeks in three mixed-sex colonies of Long Evans rats. After colony formation, a despotic dominance system was established between the males. This paper focuses on differences between subdominant colony and pair-housed control males. A reduced body mass development and hormonal status in subdominant males indicate stressful colony conditions. Subdominant males had lower numbers of CD4 and CD8 T cells, pronounced granulocytosis and reduced lymphocyte proliferation rates as compared with controls. The persistency of changes in subdominant males offers the opportunity to investigate the effects of long-term immuno-modulation on health.
Descriptors: Long Evans rats, colony housing, long term, behavior, immunological, pair housed, males.
Steyermark, A.C. and P.J. Mueller (2002). Cage size affects feeding and energetics of captive rodents. Physiological and Biochemical Zoology 75(2): 209-213. ISSN: 1522-2152.
Descriptors: captive rodents, cage size, effects on feeding and energetics, weight, body mass, energy expenditure.
Stub, C., H.M. Ritskes, A.K. Olsen, T.C. Krohn, and A.K. Hansen (2004). Fluctuating asymmetry in relation to single housing versus group housing in three inbred mouse strains. Scandinavian Journal of Laboratory Animal Science 31(4): 245-249. ISSN: 0901-3393.
Descriptors: environmental stress, fluctuating asymmetry, group housing, single housing, inbred mouse strains.
Tang, X. and L.D. Sanford (2005). Home cage activity and activity-based measures of anxiety in 129P3/J, 129X1/SvJ and C57BL/6J mice. Physiology and Behavior 84(1): 105-115. ISSN: 0031-9384.
Abstract: We investigated the home cage activity and emotional behavior in mouse strains used as background for many studies of altered genes [C57BL/6J (B6, n=20), 129X1/SvJ (X1, n=20) and 129P3/J (P3, n=19)]. In their home cages, X1 and P3 mice exhibited less locomotion than did B6 mice, and the X1 mice showed significantly greater rearing than B6 and P3 mice did. A battery of three tests conducted in an open field (open field, emergence and novel object) revealed strain rankings of B6>X1>P3 or B6>X1=P3 in most activity variables. Significant correlations were found between home cage activity and activity in each of three tests, but not in all observation periods. Strain rankings on the elevated zero maze test were B6=X1>P3 in the number of stretched-attend body postures (SAPS) during the initial 6-min exposure for naive mice. Naive and nonnaive mice showed significantly different behaviors on the elevated zero maze. The results suggest that rankings on anxiety are P3>X1>B6 and that B6 mice have greater exploration in a novel environment compared with X1 and P3 mice. However, anxiety-like behaviors differed among strains in open-field-based tests and in the zero maze, and testing experience impacted performance on the zero maze. The findings illustrate that test variations and experience can influence performance and suggest the need for the consideration of how these factors interact with background strains in assessing gene-altered mice.
Descriptors: mice, home cage activity, anxiety, locomotion, behavior, X1 mice, P3 mice, B6 mice.
Tang, X. and L.D. Sanford (2002). Telemetric recording of sleep and home cage activity in mice. Sleep 25(6): 691-9. ISSN: 0161-8105.
Abstract: STUDY OBJECTIVES: This study assessed differences in spontaneous sleep and locomotor activity in inbred and hybrid mouse strains and evaluated telemetry for recording sleep in mice. DESIGN: Uninterrupted recordings of sleep and home cage activity were obtained in four mouse strains. Pre-operative and post-operative home cage activity was obtained in two strains. SETTINGS: N/A PARTICIPANTS: The subjects were mice of three inbred (C57BL/6J (B6), n=25; BALB/cJ (C), n=24; DBA/2J (D2), n=30) strains and one hybrid (CB6F1/J (CB6: C x B6), n=19) strain. INTERVENTIONS: Electroencephalogram (EEG) and activity were recorded by telemetry, and behavioral states were visually scored based on EEG and activity records. Home cage activity was determined utilizing photobeam interruptions. MEASUREMENTS AND RESULTS: 1) Among the three inbred strains: C mice had the least sleep and the greatest amount of activity; D2 mice exhibited the least non-rapid-eye-movement (NREM) sleep, the longest average NREM-bout length, and the greatest diurnal ratio of sleep and were the most inactive; B6 mice had the most sleep and an intermediate activity level; no differences among inbred strains were observed in total REM. The CB6 mice exhibited intermediate levels of total sleep and activity and had greater amounts of REM compared to its parental strains. 2) Total operative mortality was 9.3%, with all deaths occurring within 3 to 9 days after the operation; significant reductions in activity were observed after the operation. CONCLUSION: Differences in spontaneous sleep and activity exist among inbred and hybrid mouse strains. Accurate determination of sleep states in mice can be achieved with telemetrically recorded EEG and activity.
Descriptors: mice, sleep, home cage activity, telemetric recording, locomotor activity, behavior, physiology, electrocardiography.
Teixeira, M.A., I.L. Sinhorini, N.L. Souza, and J.L.B. Merusse (1999). Microenvironmental ventilation system for laboratory animal facilities with air distribution by means of plennum chambers. Animal Technology 50(3): 187-194. ISSN: 0264-4754.
NAL Call Number: QL55.I5
Descriptors: mice, cages, artificial ventilation, air flow, animal welfare, air quality, ammonia.
Tsai, P.P., D. Oppermann, H.D. Stelzer, M. Mahler, and H. Hackbarth (2003). The effects of different rack systems on the breeding performance of DBA/2 mice. Laboratory Animals 37(1): 44-53. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Abstract: Housing systems for laboratory animals have been developed over a long time. Micro-environmental systems such as positive, individually ventilated caging systems and forced-air-ventilated systems are increasingly used by many researchers to reduce cross contamination between cages. There have been many investigations of the impact of these systems on the health of animals, the light intensity, the relative humidity and temperature of cages, the concentration of ammonia and CO(2), and other factors in the cages. The aim of the present study was to compare the effects of different rack systems and to understand the influence of environmental enrichment on the breeding performance of mice. Sixty DBA/2 breeding pairs were used for this experiment. Animals were kept in three rack systems: a ventilated cabinet, a normal open rack and an individually ventilated cage rack (IVC rack) with enriched or non-enriched type II elongated Makrolon cages. Reproduction performance was recorded from 10 to 40 weeks of age. In all three rack systems there was a similar breeding index (pups/dam/week) in non-enriched groups during the long-term breeding period, but the coefficients of variation in the IVC rack were higher for most parameters. This type of enrichment seems to lead to a decrease in the number of pups born, especially in the IVC group. However, there was no significant difference in breeding index (young weaned/female/week).
Descriptors: mice, breeding performance, housing, rack systems, effects, aging, body weight, litter size, DBA 2 mice.
Van Loo, P.L., J.A. Mol, J.M. Koolhaas, B.F. Van Zutphen, and V. Baumans (2001). Modulation of aggression in male mice: influence of group size and cage size. Physiology and Behavior 72(5): 675-83. ISSN: 0031-9384.
Abstract: Aggression in group-housed male mice is known to be influenced by both cage size and group size. However, the interdependency of these two parameters has not been studied yet. In this study, the level of aggression in groups of three, five, or eight male BALB/c mice housed in cages with a floor size of either 80 or 125 cm(2)/animal was estimated weekly after cage cleaning for a period of 14 weeks. Furthermore, urine corticosterone levels, food and water intake, body weight, and number of wounds were measured weekly. At the end of the experiment, tyrosine hydroxylase (TH) activity, testosterone levels, and weight of spleen, thymus, testes, and seminal vesicles were determined. Results indicate a moderate increase of intermale aggression in larger cages when compared to the smaller cages. Aggression in groups of eight animals was considerably higher than in groups of three animals. The increase of agonistic behavior was observed both in dominant and subordinate animals. Physiological parameters indicate differences in stress levels between dominant and subordinate animals. It is concluded that aggressive behavior in group-housed male BALB/c mice is best prevented by housing the animals in small groups of three to five animals, while decreasing floor size per animal may be used as a temporary solution to decrease high levels of aggression in an existing social group.
Descriptors: mice, male, aggression, social environment, modulation, group housed, stress levels, group size, cage size.
Varlinskaya, E.I., L.P. Spear, and N.E. Spear (1999). Social behavior and social motivation in adolescent rats: role of housing conditions and partner's activity. Physiology and Behavior 67(4): 475-82. ISSN: 0031-9384.
Abstract: The present study investigated 1) the effects of individual and grouped housing on social investigation, social contact behavior, and play behavior in adolescent rats tested with low socially active (grouped) and high socially active (isolated) play partners; and 2) the effects of long-term (8 days) and short-term (24 h) isolation on social behavioral manifestations and social motivation in terms of preference or avoidance of play partners. Social isolation of adolescent rats activated play behavior and social behaviors different from play, but play was predominantly affected under the conditions of this study. Long-term isolation was more effective than short-term, and resulted in greater manifestation of play and social preference. Adolescent rats were able to modify their social behaviors in response to social activity of the play partner: in isolated animals exposed to low socially active group-housed partners, play behavior was transformed into social activities unrelated to play; exposure of group-housed adolescents to high socially active previously isolated partners resulted in an increase of play behavior. Testing that allowed avoidance of social contacts revealed a dissociation between manifestations of play behavior and social motivation: group-housed play partners of isolated animals showed elevated levels of play behavior but a tendency to avoid their isolated pairmates.
Descriptors: rats, housing, social behavior, social environment, aging, activity, social isolation, play.
Waiblinger, E. and B. Konig (2004). Refinement of gerbil housing and husbandry in the laboratory. ATLA, Alternatives to Laboratory Animals 32(Supplement 1A): 163-169. ISSN: 0261-1929.
NAL Call Number: Z7994.L3A5
Descriptors: gerbil, housing, husbandry, behavior, stereotypic, digging, chewing, refinement, welfare.
Westenbroek, C., J.A. Den Boer, M. Gerrits, and G.J. Ter Horst (2003). Chronic stress coping in isolated and socially housed male and female rats. Hormones and Behavior 44(1): 83. ISSN: 0018-506X.
Descriptors: rats, male, female, housing, isolated, socially, chronic stress, coping, behavior.
Notes: Meeting Information: Society for Behavioral Neuroendocrinology Annual Meeting, June 25-28, 2003, Cincinnati, OH, USA.
Westenbroek, C., J.A. Den Boer, M. Veenhuis, and G.J. Ter Horst (2004). Chronic stress and social housing differentially affect neurogenesis in male and female rats. Brain Research Bulletin 64(4): 303-308. ISSN: 0361-9230.
Abstract: Stress plays an important role in the development of affective disorders. Women show a higher prevalence for these disorders than men. The course of a depression is thought to be positively influenced by social support. We have used a chronic stress model in which rats received foot-shocks daily for 3 weeks. Since rats are social animals we hypothesised that 'social support' might reduce the adverse effects of chronic stress. To test this hypothesis, male and female rats were housed individually or socially in unisex groups of four rats. The proliferation marker bromodeoxyuridine (BrdU) was injected 2 weeks before the sacrifice to investigate if stress and social housing influenced the survival of proliferating cells in the dentate gyrus (DG). To investigate changes in proliferation, another group of rats was sacrificed the day after the last BrdU injection. Stress significantly decreased BrdU labelling in individually housed males and not significantly in socially housed males. In individually housed females stress increased BrdU labelling, which was prevented by social housing. The increase found in females is most likely caused by differences in survival rate, since cell proliferation was not affected by stress or housing conditions. These results indicate that social support can affect neurogenesis in both female and male rats, however in a different way.
Descriptors: chronic stress, social housing, neurogenesis, effect, rats, male, female.
Westenbroek, C., G.J. Ter Horst, M.H. Roos, S.D. Kuipers, A. Trentani, and J.A. Den Boer (2003). Gender-specific effects of social housing in rats after chronic mild stress exposure. Progress in Neuro Psychopharmacology and Biological Psychiatry 27(1): 21-30. ISSN: 0278-5846.
Abstract: Stress plays an important role in the development of affective disorders. Women show a higher prevalence for these disorders then men. The course of a depression is thought to be positively influenced by social support. The authors have used a chronic mild stress model in which rats received footshocks daily for 3 weeks. Since rats are social animals we hypothesized that 'social support' might reduce the adverse effects of chronic stress. To test this hypothesis, male and female rats were housed individually or socially in unisex groups of four rats. An open field test was repeated four times during the 3 weeks of treatment. Neuronal activation in the paraventricular nucleus of the hypothalamus (PVN) and dorsal raphe nucleus (DRN) in response to stress was measured the last day with c-fos. Chronic stress exposure increased locomotor activity in the open field, especially during the first minute. This was most pronounced in the individually housed females. In females, social housing prevented the stress-induced increase of locomotor activity, while in males social housing had no effect. Fos immunoreactive (FOS-ir) in the PVN was increased in all stress-exposed groups, except for the socially housed females due to a higher FOS-ir in controls. Individually housed males and socially housed females showed increased FOS-ir in the DRN and the increase was almost significant in socially housed males. In conclusion: These results show that social housing can enhance coping with stress in female rats, whereas in male rats group housing did not have a positive influence on stress-sensitivity.
Descriptors: sex differences, social environment, housing, stress, rats, social housing, gender effects, female, male.
Zenner, L. and J.P. Regnault (2000). Ten-year long monitoring of laboratory mouse and rat colonies in French facilities: a retrospective study. Laboratory Animals 34(1): 76-83. ISSN: 0023-6772.
NAL Call Number: QL55.A1L3
Descriptors: mice, rats, serological surveys, parainfluenza 1 virus, murine encephalomyelitis virus, parvovirus, murine hepatitis virus, murine pneumonia virus, coronavirus, SPF husbandry, disease prevalence, seroprevalence, France, Kilham's rat virus.