Spironucleus muris is an unacceptable infectious agent for most rodent colonies. Exposure of sentinel mice to dirty bedding and examination of sentinel intestinal smears was not sufficient for identification of the extent of spironucleosis within 1 mouse room. Clinical abnormalities were not reported in the animals housed in the room despite extensive breeding and a preponderance of mice genetically engineered to have nonfunctional T and B cells. In addition, researchers reported that the infection had not altered their research data. During investigation of the outbreak, direct intestinal smears performed on related animals (conspecifics, offspring, or siblings) revealed that immunodeficient mice often tested negative whereas the immunocompetent cohort tested positive. In this study, we used culled colony animals and compared direct intestinal exam test results with histologic results. The comparison showed the extent of false negatives that may occur when direct intestinal exam alone is used to detect this protozoon. Sensitivity of the direct intestinal exam for detection of S. muris was calculated to be 71%, while histology sensitivity was 91%. In light of the study results and an extensive literature review, we revised our health surveillance plan so that the age and duration of exposure to dirty bedding among sentinel mice is varied at the time of testing.

The present experiment was designed to investigate the effect of housing conditions on task performance and corticosterone response. Two groups of male F344BNF1 rats were housed on a ventilated rack with ad libitum access to water and a restricted feeding regime. Group 1 was housed in solid-bottom caging with corn cob bedding, whereas group 2 was housed in wire-bottom caging. After learning an operant task, each rat was exposed to acute restraint followed 48 h later by exposure to continuous light. Corticosterone concentrations were determined before and after exposure to each intervention. Contrary to assumptions, housing did not affect task performance. Baseline corticosterone concentrations were similar for the 2 experimental groups, but corticosterone concentrations were significantly higher for the wire-bottom group than the solid-bottom group immediately after the restraint and remained elevated 2 d later. Corticosterone levels decreased in both groups after exposure to continuous light. Overall, the data indicate that subtle but significant differences occur in responses of rats housed on wire-bottom versus solid-bottom caging when the animals are exposed to acute restraint.

Dogs are susceptible to different tickborne infections, including members of the Anaplasmataceae (Ehrlichia canis, E. ewingii, E. chaffeensis, Anaplasma phagocytophilum, A. platys), Borrelia burgdorferi, and Rickettsia rickettsii. These diseases can manifest with clinical signs including fever, anorexia, malaise, lameness, rash, and bleeding episodes; however, these signs are nonpathognomonic, and infections can occur in the absence of clinical signs. Hematologic abnormalities can include leukopenia, thrombocytopenia, hyperproteinemia and hypergammaglobulinemia. In biomedical research, diseases such as canine monocytic ehrlichiosis, Lyme disease, and Rocky Mountain spotted fever may cause morbidity among exposed dogs and confound research results. Random-source dogs are susceptible to these diseases because of their increased risk of arthropod exposure. Nonpurpose bred, randomly selected conditioned dogs (n = 21) were examined; blood samples were taken for hematology, biochemistry analysis, tickborne pathogen serology, and PCR. Of these, 2 dogs (10% of the population) presented with illness characterized by fever, malaise, lameness, or hemostatic abnormalities, and 15 (71%) had antibodies to one or more tickborne pathogens. No specific hematologic or biochemical differences were apparent between seronegative dogs and seropositive dogs reactive to all 3 pathogens. E. canis and B. burgdorferi PCR of tissues and blood were negative for all dogs. PCR amplification of several Ehrlichia and Anaplasma genes yielded no positive samples. From this cohort of dogs, serologic and molecular results indicate prior exposure without active infection or clinical disease. Exposure to and potential for infection with these bacteria and other pathogens may contribute to blood and tissue alterations that could confound experiments and lead to misinterpretation of data in canine models.

To investigate maternal behavior in laboratory-born, individually reared monkeys, we carried out a statistical analysis of 896 long-tailed macaques (Macaca fascicularis) based on breeding records of the Tsukuba Primate Research Center (National Institute of Biomedical Innovation, Ibaraki, Japan). Data were obtained from 3266 cases of normal delivery between 1982 and 2004. In each case, maternal behavior was classified as either adequate or inadequate. We examined the effects of parity and the sex of the infant on maternal behavior. We also investigated the similarity of maternal behavior between mothers and their daughters and the effect of quality of maternal care received in infancy on maternal behavior as an adult. The results showed that only the mother's number of deliveries had a significant effect on maternal behavior. The greatest improvement of maternal behavior was observed at second delivery, and the incidence of improvement kept being above 0 thereafter. Our results suggest that, as reported previously, parity is an important factor in the adequacy of maternal behavior in individually reared monkeys.

The objective of this study was to determine the level of anesthesia attained in Xenopus laevis frogs using a propofol bath administration. Thirty-three nonbreeding female Xenopus laevis frogs were used. At 175 mg/l, all frogs died after bath administration. An appropriate anesthetic dose was determined to be 88 mg/l for 15 min. After administration of this dose, the acetic acid test, withdrawal reflex, righting reflex, heart rate, and respiratory frequency were used to evaluate central nervous system depression. Pharmacokinetics of propofol were calculated after blood concentration determination by tandem liquid chromatography–mass spectrometry analyses. Short-duration anesthesia (less than 30 min) was obtained, and in many frogs, muscular fasciculation was seen during the acetic acid test. The area under the time–concentration curve (AUC_0-t) was 24.07 µg˙min/ml, and AUC_inf was 24.71 µg˙min/ml. The elimination half-life was 1.18 h. When administered as a single-bath immersion for 15 min, propofol does not appear to be a safe and effective anesthetic for Xenopus laevis frogs, due to a narrow dose-effect window, short duration, and shallow level of anesthesia obtained.

The purpose of this study was to develop a rapid DNA isolation method and a sensitive and specific PCR assay for detecting Spironucleus muris in mouse tissue and fecal samples. A PCR assay based on the carboxy terminus of the elongation factor 1α gene was developed; the PCR product was confirmed by nucleic acid sequencing and nested PCR. The new PCR assay then was used to test feces from animals that had been screened for S. muris by using direct intestinal examination and histology. The PCR assay was determined to be a more sensitive test than either direct intestinal examination or intestinal histology. To our knowledge, this assay represents the first use of a PCR-based diagnostic screening method to confirm the presence of S. muris in murine tissue and fecal samples.

Rats are used widely in ischemia–reperfusion and other heart experiments, but current protocols for thoracotomy have serious shortcomings. Median sternotomy causes bleeding from sternum itself and the internal thoracic arteries, whereas left thoracotomy requires exteriorization of the heart and its reintroduction after completion of the procedure and often is complicated by traction or torsion of the cardiopulmonary bundle and atelectasis in the left lung. Here we describe a new, terminal procedure that minimizes blood loss and allows wide access to the heart without disturbing its anatomic position. Transverse thoracotomy, preferably through the fifth intercostal space, is performed after double ligature of both internal thoracic arteries 1 intercostal space above and 1 below the incision. Blood loss is minimal and occurs mainly with dissection of deep pectoral muscles and intercostal muscles, and the animal is better ventilated than with conventional protocols. We believe that our procedure is superior to existing techniques because it minimizes blood loss during intervention, does not disturb the anatomic position of the heart, and allows wide access to the organ for experimental manipulation.

Bronchoalveolar lavage (BAL) by means of bronchoscopy is a diagnostic tool frequently used for clinical and research purposes in nonhuman primates. Although many institutions use this procedure, the technique is not standardized. One technical aspect that can vary is the method by which fluid is recovered. The purpose of this study was to evaluate differences between 2 different BAL aspiration techniques. Bronchoscopy and BAL fluid collection were performed on 20 rhesus macaques (Macaca mulatta). Data collected for comparison included heart rate, oxygen saturation levels, rectal temperature, volume of fluid collected, total cell count, cell viability, differential cell count, and flow cytometry. Results showed no significant differences in the heart rate, oxygen saturation, or body temperature between the 2 groups. Likewise, differential cell counts and cell viability studies of the retrieved fluid did not differ between methods. Compared with the conventional technique, the modified aspiration technique led to an 8.3% increase in overall fluid yield and a higher concentration of cells recovered. These differences are statistically significant and likely will be clinically relevant in the context of diagnosis.

Indwelling central venous catheters are often used to facilitate frequent phlebotomy while minimizing stress and anesthetic effects on animals. However, nonhuman primates with central venous catheters must wear protective jackets. Jackets routinely are removed for aerosol exposure to agents and respiratory measurements by whole-body plethysmography (WBP) because of the potentially confounding effects of jackets on these procedures. However, removing the jacket may dislodge the catheter, making it unusable. Using each animal as its own control, we tested 12 African green monkeys to determine whether minute volume, tidal volume, respiratory rate, or accumulated volume measurements by WBP differed depending on whether the animal wore a protective jacket or not. We found no statistical differences in any measured respiratory parameter and concluded that the jackets could be left in place on the animal while undergoing plethysmography without compromising the calculations for determining the inhaled dose of aerosolized agent. In addition, this study revealed no obvious contraindications to leaving the jacket in place in other nonhuman primate species, provided that the jacket fits appropriately and that plethysmography is performed correctly.

This report describes the diagnosis and treatment of pulmonary arterial hypertension (PAH) in an adult male captive chimpanzee. Although cardiovascular disease in general is common in human and great apes, diagnosis and treatment of PAH in nonhuman primates are uncommon. In the case we present, the adult chimpanzee was diagnosed with an arrhythmia during an annual physical examination and later with PAH during a scheduled cardiovascular evaluation. PAH can either be primary or secondary and can lead to right ventricular overload and heart failure. This description is the first case study of pulmonary arterial hypertension in a great ape species.

Acute respiratory distress syndrome (ARDS) is an important and potentially life-threatening complication in humans that arises subsequent to a variety of primary insults including noxious fume inhalation, infection, and trauma. Here we describe the first two cases of ARDS reported in association with postoperative complications in rhesus macaques. In agreement with the multifactorial nature of the human syndrome, ARDS in one monkey was attributed to sepsis, whereas in the other it was ascribed to neurogenic trauma. Despite the different etiologies, both monkeys demonstrated clinical features of ARDS, including progressive dyspnea and pulmonary edema, and syndrome-defining histopathologic criteria including edema with intraalveolar neutrophils, fibrinohemorrhagic effusions with crescentic membranes, and interstitial vascular degeneration. Recognition and aggressive treatment of ARDS at an early stage may improve survival rates in dyspneic nonhuman primates with underlying extrapulmonary diseases.