Laboratory Animal Science 

About: Laboratory Animal Science is an academic journal. The journal publishes majorly in the area(s): Virus & Antibody. It has an ISSN identifier of 0023-6764. Over the lifetime, 3407 publications have been published receiving 50190 citations.

Body condition scoring: a rapid and accurate method for assessing health status in mice.

Abstract: Practical, rapid, noninvasive methods for assessing healthstatus and establishing endpoints are needed in mouse ex-periments in which wasting and death are a potential end-point, including aging and toxicology studies, ascitesproduction, and phenotype analysis in mutant mouse colo-nies. Current methods for assessing the health status of amouse and establishing endpoints might include observa-tion of behavior, assessment of physical appearance, andmeasurement of body weight (BW). Behavioral parametersinclude observation of unprovoked behavior and responsesto external stimuli. Classic changes in physical appearanceinclude exophthalmia or enophthalmia (bulging or sunkeneyes, respectively), nasal or ocular discharge, rough coat, andhunched back. These observations, as well as additional onesparticular to an experimental procedure or to the geneticmakeup of an animal, have been suggested as standard indi-cators of ill health (1–4). These clinical indicators can bescored as degree-of-deviation-from-normal, thereby allowingan animal to be monitored over time as health declines (1–4). Decreased food and water consumption is an importantsign of deteriorating health (4), which generally results inloss of BW; support for using weight loss as an indicator ofpoor health in rodents comes from the study by Redgate etal. (5). They determined that 7 or more consecutive days ofweight loss in central nervous system tumor-bearing ratscorrelated well with irreversible progression to death. How-ever, Beynen et al. (2) found that observation of behavior andphysical appearance was largely ineffective for discriminat-ing between gallstone-bearing mice and healthy controls,and weight loss was significantly different between the twogroups of mice for the males but not the females. They con-cluded that response to palpation of the right hypochon-drium (i.e., signs of a painful response) was the bestindicator of gallstones for males and females.Twenty percent loss of rodent BW or prolonged weightloss (progressing to an emaciated state) are generally estab-lished criteria for euthanasia (3, 6). However, there are prac-tical problems with the measurement of BW, which may notyield an accurate measure of fat stores and muscle mass,because reduction of fat stores and muscle mass (as mea-sured by BW) is masked if weight loss is displaced by tumorgrowth, organ enlargement, or intraperitoneal fluid accumu-lation. Furthermore, the reference weight of a healthymouse will vary according to sex, age, body frame size, andin females, pregnancy status. Scoring body condition (BC) byobserving the amount of flesh covering bony protuberancesis largely independent of the aforementioned confoundingvariables. The technique of BC scoring as a method forevaluating animal condition and nutritional state has al-ready been validated for use in dairy cows (7–9), beef cows(10), goats (11), sheep (12), and horses (13). In cows, BC scorecorrelates with the amount of subcutaneous fat stores (7, 10)and nutritional status (14). Additionally, abnormal loss of BCwas found to be an indicator of mastitis in dairy cows (15).Our goals were to evaluate the accuracy of the BC scoringtechnique in assessing the health of mice that have organ en-largement concurrent with declining health; compare the accu-racy of this method with that of using BW for assessing healthstatus in these animals; and determine the interobserver reli-ability of the BC scoring technique. P- and E-Selectin doubledeficient (P/E

Normal Physiological Values for Conscious Pigs Used in Biomedical Research

Abstract: Although the domestic pig is rapidly becoming an animal of choice in certain areas of biomedical research requiring a large animal model, effective utilization of the species is often encumbered by a lack of reference values for common functional variables. To address this problem, normal data for over 100 physiologic or related variables were collected from conscious chronically instrumented animals that were maintained under near basal conditions. Included were measurements of body composition, fluid volumes, blood physical and biochemical characteristics, blood gas and acid-base status, plasma hormone levels, energy metabolism, renal function, hemodynamics and pulmonary function. Most porcine values were similar to those collected under comparable conditions from humans. Compared to adult man, however, pigs had higher values for extracellular space, plasma volume, arterial pH, plasma bicarbonate, cardiac output, arterial pressure, expired ventilation, heat production, and core temperature, and lower values for red cell volume, hemoglobin level, plasma osmotic and oncotic pressure, arterial O2 content, renal blood flow and glomerular filtration rate. Many of these deviations were due to immaturity. Nevertheless, we have found pigs to be an excellent large animal model for a variety of functional studies.

Phytoestrogen content of purified, open- and closed-formula laboratory animal diets.

Abstract: BACKGROUND AND PURPOSE Phytoestrogens exert estrogenic effects on the central nervous system, induce estrus, and stimulate growth of the genital tract of female animals. Over 300 plants and plant products, including some used in laboratory animal diets, contain phytoestrogens. Therefore, the source and concentration of phytoestrogens in rodent diets were determined. METHODS Twelve rodent diets and six major dietary ingredients were assayed for phytoestrogens (daidzein, genistein, formononetin, biochanin A, and coumestrol), using high-performance liquid chromatography. Three rodent diets recently formulated to reduce phytoestrogen content also were assayed. RESULTS Formononetin, biochanin A, and coumestrol were not detected. Soybean meal was the major source of daidzein and genistein; their concentrations were directly correlated to the percentage of soybean meal in each diet. CONCLUSIONS High, variable concentrations of daidzein and genistein are present in some rodent diets, and dietary phytoestrogens have the potential to alter results of studies of estrogenicity. Careful attention should be given to diet phytoestrogen content, and their concentration should be reported. A standardized, open-formula diet in which estrogenic substances have been reduced to levels that do not alter results of studies that are influenced by exogenous estrogens is recommended.

Dietary intake, energy metabolism, and excretory losses of adult male germfree Wistar rats

Abstract: Adult germfree rats excreted 87% more calories with the feces than comparable conventional rats, but this loss was compensated by an 18% higher intake. As a result, energy utilization of germfree and conventional rats was similar (148 and 143 kcal/kg/day, respectively), although the germfree rat metabolized only 71.9% of its dietary intake, versus the conventional rat's 80%. Germfree rats consumed 33% more water than conventional rats. Both excreted approximately 33% of water intake via feces and urine, but the germfree rat excreted 56% of this with the feces, the conventional rat only 15%. Cecectomy of the germfree rat reduced water loss via the feces, but the total daily excretion of fecal dry matter remained comparable to that of the intact germfree rat. The increase in fecal dry matter excretion demonstrated by the germfree rat can be largely accounted for in terms of water-soluble organic material. The data imply that the lower oxygen consumption of the germfree rat is not coupled to a reduction in metabolized energy, but may be an anomaly linked to cecal stasis and enlargement.

Efficacy of tribromoethanol anesthesia in mice.

Abstract: We undertook a retrospective study to evaluate the efficacy, safety, and suitability of tribromoethanol (0.2 ml/10 g body weight of a 1.2% solution) as a surgical anesthetic in mice. We compiled records of embryo transfer during a 2.5-year period (1989-1991) and examined mice subjected to several other procedures requiring anesthesia. We documented a low rate of mortality and morbidity (< 1%) and the absence of any significant abdominal adhesions or inflammatory response. The rapid induction and recovery, adequate surgical plane of anesthesia, and lack of complications make this anesthetic effective and simple to use. Precautions necessary to prevent decomposition of the anesthetic, storage in the dark at 4 degrees C, were minimal.