Enzootic infection with mouse parvovirus (MPV) remains a common problem in laboratory colonies, and diagnosis of MPV infection is complicated by viral and host factors. The effect of an underlying viral infection on MPV infection has not previously been investigated. We assessed the effect of murine norovirus (MNV) infection, the most prevalent infectious agent in laboratory mice, on MPV shedding, tissue distribution and transmission. Fecal MPV shedding persisted longer in BALB/c mice infected with MNV 1 wk prior to MPV infection than in mice infected with MPV only, but transmission of MPV to soiled-bedding sentinels was not prolonged in coinfected mice. MPV DNA levels in coinfected BALB/c mice were higher in mesenteric lymph nodes and spleens at 1 and 2 wk after inoculation and in small intestines at 1 wk after inoculation compared with levels in mice infected with MPV only. In C57BL/6 mice, fecal shedding was prolonged, but no difference in soiled bedding transmission or MPV DNA levels in tissues was detected between singly and coinfected mice. MPV DNA levels in singly and coinfected SW mice were similar. MPV DNA levels were highest in SW, intermediate in BALB/c and lowest in C57BL/6 mice. MPV DNA levels in mesenteric lymph nodes of BALB/c and SW mice exceeded those in small intestines and feces, whereas the inverse occurred in C57BL/6 mice. In conclusion, MNV infection increased the duration of MPV shedding and increased MPV DNA levels in tissues of BALB/c mice.

Insufficient wear of rodent incisors often results in malocclusion and rapid tooth elongation. This condition may go undetected for a prolonged time and have a negative effect on affected animals' welfare. Dental overgrowth can lead to undernutrition due to chronic difficulty in feeding and may cause trauma to the surrounding tissues, potentially ultimately resulting in death. Here we describe the increased incidence of malocclusion observed during a longitudinal study of the normal growth and aging of Wistar rats. Histologic examination of the temporomandibular joint of affected animals did not reveal any inflammatory or degenerative changes. Because no environmental factor could be implicated in the condition, we considered that aging or genetic factors were responsible for its appearance. We conclude that special attention should be given to the potential appearance of malocclusion during long-term rodent studies, because its incidence may adversely affect the animals' health and general wellbeing.

The chemistry and hemostatic parameters of class B vendor cats (Felis catus) can show wide levels of variation, possibly because of initial health status. We compared prothrombin time, partial thromboplastin time, common pathway assay and thrombin time between Class B vendor cats (n = 30) and a control group of healthy cats (n = 16). The antiprotease activities of antiXa, antiIIa, heparin cofactor II, and antithrombin were measured also. Plasma samples from citrated blood were analyzed by using standard clotting assays and commercially available chromogenic substrate assays. Tests for homogeneity of variances and 1-way ANOVA were used to test for significant differences between groups. Results of ANOVA were highly significant between groups for heparin cofactor II and Heptest activity levels. Variances were significantly different between groups for prothrombin time; therefore, an ANOVA was not done. These studies suggest that the class B cats exhibited sufficiently wide variations in their coagulation parameters that they may not be optimal subjects for vascular or cardiovascular research.

Heart growth in 6 female beagle dogs was measured by using M-mode echocardiography at 4, 7, 10, 13, 17, and 21 mo of age. The same 6 dogs were evaluated throughout the study to establish when cardiac development ends in this breed. The following parameters were measured during systole and diastole: left ventricle posterior wall thickness, interventricular septal thickness, left ventricular internal dimension, left atrial dimension during ventricular systole, aortic root dimension at end diastole, E-point to septal separation, left ventricular preejection period, ejection time of the left ventricular outflow, and time between the cessation and onset of the mitral inflow intervals. The percentage of the left ventricle posterior wall thickening, fractional shortening, ejection fraction, left ventricular end systolic and end-diastolic volumes, ratio of the left atrial dimension to aortic root dimension, and the Tei index of myocardial performance were calculated. The heart rate was measured by cardiac auscultation. The influence of ageing on each echocardiographic parameter and relationships with body weight and surface were studied. Results show that cardiac development in female beagles can be considered finished by the age of 1 y, perhaps as soon as 7 mo. The cardiac indexes studied were unaffected by the age and corporal dimensions, confirming the usefulness of these parameters for evaluating cardiac functionality alterations independent of a dog's age and body weight or surface area.

The Animal Welfare Regulations, which define legal requirements for the care and use of gerbils in research and testing, and the Guide for the Care and Use of Laboratory Animals describe feeding practices for several species of rodents but not Mongolian gerbils (Meriones unguiculatus). To investigate whether the method of feed presentation affected reproduction and growth of gerbils, we compared the reproductive performance and rate of growth of gerbils fed on the cage floor, by hopper (J-feeder), or by wire-bar cage lid. Reproductive parameters of 10 breeding pairs for each method of feeding were followed for 63 d and did not differ between methods. To investigate the effect of feeding method on weight gain in juvenile gerbils, groups of 80 male and 80 female weanling gerbils per feeding method were fed for 5 consecutive weeks after weaning and weighed weekly. Gerbils fed on the cage floor and by means of J-feeders were significantly heavier than were those fed by using a wire-bar top. Our findings indicate that feeding gerbils by using J-feeders or on the cage floor are both acceptable practices.

Streptozotocin is widely used to induce diabetes in laboratory animals through multiple low-dose or single high-dose intraperitoneal injections. HPLC analysis has shown that the composition of the solution may change considerably during the first 2 h after dissolution due to equilibration of the 2 anomers (α and β) of streptozotocin. Because of the drug's alleged instability in solution, the typical recommendation is to administer streptozotocin within 10 min after dissolution. We compared the induction of diabetes in NOD/SCID mice by injection of a single high dose of freshly made or anomer-equilibrated streptozotocin solution. Solutions were prepared from dry compound containing 85% of the α anomer, which is the more toxic of the 2. Body weight and nonfasting blood glucose levels were measured weekly for 8 wk. Both solutions induced long-term hyperglycemia, but blood glucose levels and mortality were higher and damage to pancreatic islands more pronounced in the mice receiving freshly prepared solution. A small proportion of mice did not respond in both treatment groups. If stored at 4 °C in the dark, the anomer-equilibrated solution retains its biologic activity for at least 40 d; under those conditions the streptozotocin content decreases by 0.1% daily, as determined by HPLC. Anomer-equilibrated streptozotocin solution has several practical advantages, and we recommend its use as standard for the induction of experimental diabetes because this practice may improve reproducibility and comparison of results between different laboratories.

Orthotopic liver transplantation in mice and rats is used to study a wide range of scientific questions. Inhalant anesthesia is widely used in liver transplantation models in rodents, but drawbacks of inhalant anesthetics include issues of cost, safety, and ease of use. The goal here was to find an effective injection anesthesia protocol that would not directly influence metabolic or functional parameters after liver transplantation. We compared intraperitoneal injection of a ketamine–xylazine–acepromazine cocktail (KXA) with isoflurane during 50% liver transplantation in mice and rats. Anesthesia with KXA had rapid induction (5 ± 3 min) and a long duration of surgical anesthesia (70 ± 10 min). The 2 methods of anesthesia produced no significant differences in liver injury (histology, serum alanine aminotransferase and total bilirubin concentrations), inflammation (IL6, TNFα, myeloperoxidase activity), regeneration (incorporation of 5-bromo-2′-deoxyuridine, mitotic index, restitution of liver weight), or 7-d survival. In conclusion, a KXA regimen is a safe and effective injectable anesthetic for rodent liver transplantation and is a suitable substitute for currently used inhalant anesthesia. Injectable anesthetics offer advantages in terms of cost, personal safety, and ease of use and will be particularly beneficial to microsurgeons during their training period in liver transplantation.

Anesthetics can affect biochemical parameters, complicating the interpretation of laboratory results and perhaps leading to erroneous diagnoses. The present study was performed to characterize variations in selected rabbit biochemical parameters after inhalant anesthetics. Twenty New Zealand White rabbits were allocated to 2 treatment groups (n = 10 animals each), which received either halothane or isoflurane. Anesthesia was induced by using a face-mask, and rabbits were intubated for maintenance of anesthesia for 30 min. Blood samples were obtained before induction and at 1, 10, 30, 60, and 120 min and 24, 48, and 72 h after intubation. Serum cholesterol, triglycerides, albumin, total proteins, total bilirubin, sodium, potassium, chloride, calcium, and phosphorus concentrations were measured by using an autoanalyzer. Administration of halothane significantly increased serum triglyceride levels and decreased serum cholesterol, albumin, total protein, and potassium levels. Isoflurane administration increased serum triglyceride, phosphorus, and chloride concentrations and decreased serum calcium and potassium levels. Caution is required in interpreting data on serum biochemical parameters from rabbits anesthetized with halothane or isoflurane.

This study compared the cardiovascular, respiratory, anesthetic, and glucocorticoid effects of ketamine alone with ketamine–medetomidine and ketamine–midazolam in rhesus and cynomolgus macaques. Macaques were given either intramuscular ketamine (10 mg/kg), intramuscular ketamine–medetomidine (3 mg/kg; 0.15 mg/kg), or oral midazolam (1 mg/kg) followed by intramuscular ketamine (8 mg/kg). The addition of medetomidine, but not midazolam, provided muscle relaxation and abolishment of reflexes that was superior to ketamine alone. In addition, medetomidine did not cause clinically relevant effects on cardiovascular and respiratory parameters when compared with ketamine. These 3 protocols did not have significantly different effects on fecal glucocorticoid metabolites. These results suggest that medetomidine can be a valuable addition to ketamine for healthy patients, whereas oral midazolam at the tested dose does not provide additional benefits.

Invertebrates are increasing in their importance to both the public and private aquarium trade and play a vital role in biomedical research. Surgical techniques have become an important approach to obtaining data and maintaining good health in both of these areas. However, studies examining tissue reaction to suture material in invertebrates are lacking. The current study evaluated the gross and histologic reaction of Aplysia californica to 5 commonly used suture materials, including polydioxanone, black braided silk, polyglactin 910, monofilament nylon, and monofilament poliglecaprone. Histologic samples were graded on the amount of edema (score, 1 to 4), inflammation (1 to 4), and granuloma formation (1 to 4) present, and a final overall histology score (1 to 6) was assigned to each sample. Compared with untreated control tissue, all suture materials caused significantly increased tissue reaction, but the overall histology score did not differ among the suture materials. Silk was the only suture that did not have a significantly increased granuloma score when compared with the control. Although none of the suture materials evaluated seemed clearly superior for use in Aplysia, we recommend silk because of its less robust granuloma induction, which is favorable in a clinical and research setting.

Suppuration of the preputial gland in mice occurs as a septic complication of fight wounds around the external genitalia. Currently reported bacterial isolates from these lesions are limited to Staphylococcus aureus, Pasteurella pneumotropica, and Klebsiella oxytoca. In the context of a pilot experiment aimed at defining the aging phenotype of estrogen receptor β knockout (BERKO) mice, 2 male mice (1 of the BERKO line and the other from the age- and sex-matched wild-type control group) were discovered at necropsy to have preputial gland lesions. In both cases, histopathologic examination confirmed severe suppuration and abscesses of the preputial glands associated with systemic reactive (secondary) amyloidosis. Both Gram staining and Bacillus Calmette-Guérin immunohistochemistry highlighted the presence of numerous bacillary to rod-shaped bacteria within the preputial lesions. Subsequent PCR analysis coupled with denaturing gradient gel electrophoresis identified Corynebacterium mastitidis in the preputial gland abscesses. This organism is isolated infrequently from the milk of sheep with subclinical mastitis and was identified as part of the normal microflora of the human ocular surface. No information regarding the epidemiology and pathogenesis of C. mastitidis infection in laboratory animals is currently available, and to our knowledge this report is the first description of C. mastitidis infection in mice.

Here we describe a case of zygomycosis in a 4-y-old male cynomolgus monkey (Macaca fascicularis) newly received into our facility. Results of physical exam, clinical chemistry analysis, hematology, and tuberculin skin testing and routine thoracic radiographs performed during the quarantine period are reported. Routine chest radiographs taken during the quarantine period revealed enlargement of the cranial mediastinum. During quarantine, the macaque developed severe respiratory distress and was euthanized. Microscopic examination of tissue collected at the postmortem exam revealed nonseptated, branching hyphae in sections of the stomach and mediastinal lymph nodes consistent with a zygomycete. This is the first reported case of zygomycosis in a cynomolgus monkey.