Molecular detection of Bartonella henselae and Bartonella clarridgeiae in clinical samples of pet cats from Southern Italy

Bartonella henselae is considered an emerging pathogen of veterinary and medical interest that can be occasionally transmitted to humans. Cats are considered to be the only reservoir host for B. henselae. In this study, we used a nested-PCR assay to investigate the prevalence of B. henselae and Bartonella clarridgeiae DNA in peripheral blood samples, fine needle lymph node aspirate specimens and oral swabs from 85 cats in order to develop an easy diagnostic strategy for the selection of infection-free cats that are being considered as pets, especially for immunocompromised patients. Overall, molecular analysis showed that 71 cats (83.5%) tested PCR positive for the presence of B. henselae DNA. PCR amplification of DNA B. henselae produced positive products from lymph node aspirate specimens (62/85; 72.9%) similar to those obtained from blood samples (60/85; 70.6%) and higher than those from oral swabs (51/85; 60%) of cats. No PCR product was obtained for B. clarridgeiae. The simultaneous analysis of three different clinical samples in our study increased the diagnostic possibilities for B. henselae infection in the examined cats from 60–72.9% to 83.5%. Lymph node aspirates were found to be the most effective clinical samples for the detection of B. henselae and blood samples were the next best. Oral swab samples were used in this study with good results when considered in combination with blood and/or lymph node aspiration. The use of nested-PCR assay on these three clinical samples may enhance the diagnostic sensitivity for bartonellosis in cats irrespective of the clinical status of animals.     

Fertilization and blastocyst development in oocytes obtained from prepubertal and adult pigs

Polyspermic fertilization and embryo quality are important issues for the in vitro production of pig embryos. We hypothesized that oocyte donor (prepubertal gilt vs. sow) affects polyspermy and blastocyst development in vitro and that the sexual maturity of the oocyte donor affects the response to sperm concentration in the fertilization medium. In Exp. 1, oocytes of sows and gilts were mounted and stained 12 h after insemination to provide fertilization data. In Exp. 2, putative embryos were developed in vitro to 144 h post-insemination before mounting. In both experiments, cumulus-oocyte complexes (COC) were collected from ovaries of prepubertal gilts and adult sows. Sperm were added after maturation of COC for 40 to 44 h. Sperm from two boars at 0.5 to 5.0 x 10(6) sperm/mL was used for insemination. More (P < 0.01) monospermic fertilizations were observed in oocytes derived from gilts than for oocytes from sows. There were fewer (P < 0.02) penetrated sperm per fertilized oocyte in oocytes from gilts compared with sows. There were effects of semen donor (boar) on the percentage of monospermic (P < 0.01) and polyspermic (P < 0.002) fertilizations, and on the number of penetrated sperm/fertilized oocyte (P < 0.02). In Exp. 2, cleavage and blastocyst formation was evaluated at 2 and 6 d postinsemination, respectively. More (P < 0.001) blastocysts developed from sow-derived oocytes than from gilt-derived oocytes. More (P < 0.05) total cells per blastocyst were observed in embryos from sow-derived oocytes than from gilt-derived oocytes. Semen donor affected the percentage of oocytes cleaving (P < 0.02), and a boar x sperm concentration interaction affected (P < 0.05) the incidence of blastocyt formation. Results indicate that sexual maturity of the donor is not responsible for the high incidence of polyspermy in porcine in vitro fertilization. However, blastocyst development is improved by the use of oocytes from sows rather than from prepubertal gilts.     

A mechanical comparison of 4.5 mm narrow and 3.5 mm broad plating systems for stabilization of gapped fracture models

OBJECTIVE: To evaluate and compare the mechanical properties of 4.5 narrow and 3.5 broad plating systems using their respective cortical and cancellous screws in unstable, central, and eccentric gap fracture models. STUDY DESIGN: Mechanical evaluation and comparison of 2 dynamic compression plate (DCP) systems. SAMPLE POPULATION: Eighteen cortical and 30 cancellous gapped fracture models. METHODS: DCP (4.5 mm narrow, 3.5 mm broad) with their respective cortical screws were applied to cortical bone density polyurethane foam blocks to construct center gap cortical fracture models that were tested in gap closing monotonic 4-point bending. DCP (4.5 mm narrow, 3.5 mm broad) with their respective cancellous screws were applied to cancellous bone density polyurethane foam blocks to construct eccentric gap cancellous fracture models. The cancellous constructs were tested in monotonic gap opening and gap closing cantilever bending and in cyclic axial loading. Univariate and multivariate repeated measures ANOVA were used to compare the maximum loads at failure of the 4.5 mm constructs and 3.5 mm constructs. RESULTS: The 4.5 mm narrow plating system withstood significantly higher loads at failure than the 3.5 mm broad plating system in 4-point bending (P<.0001) and gap opening cantilever bending (P<.0001). The 4.5 mm system failed in gap closing cantilever bending by plastic deformation of the plate, whereas the 3.5 mm system failed by screw pullout. There was no difference between the 2 systems in cyclic axial loading. CONCLUSION: Results indicate that the 4.5 mm narrow plating system has a mechanical advantage over the 3.5 mm broad plating system for stabilization of gapped fracture models. CLINICAL RELEVANCE: The 4.5 mm narrow plating system may be mechanically advantageous compared with the 3.5 mm broad plating system for stabilizing unreconstructed comminuted long bone fractures in large dogs.     

The pathology of spontaneous paratuberculosis in the North American bison (Bison bison)

Gross and histopathologic examinations were performed on 70 North American bison (Bison bison) from a Mycobacterium avium paratuberculosis culture-positive herd. The bison examined were part of a breeding herd totaling 2,800 animals. Eight of 70 (11%) animals had gross findings of intestinal mucosal thickening, and 16 of 70 (23%) of the animals had enlarged mesenteric lymph nodes. Histologic lesions compatible with Johne's disease were diagnosed in 30 of 70 (43%) bison on the basis of the demonstration of noncaseating granulomatous inflammatory infiltrates and of one or more acid-fast bacilli characteristic of Mycobacterium avium paratuberculosis. A suspicious diagnosis of Johne's disease was obtained in 11 of 70 (16%) bison on the basis of the observation of noncaseating granulomatous inflammatory infiltrates without demonstrable acid-fast bacteria. Twenty-nine of 70 (41%) animals were assessed as histologically paratuberculosis free. Histologic results were compared to Johne's disease tests such as culture, serology, and polymerase chain reaction, which were performed on some of the cohort animals.     

Study of lipid in the ear canal in canine otitis externa with Malassezia pachydermatis

An epidemiological investigation of 120 canine otitis externa cases in 1,370 dogs was done on the incidence rate, ear pinna shapes, breeds and their relationships. Eighty-five cases (12.6%) in 672 dogs with pendulous ears and 35 cases (5.0%) in 698 dogs with erect ears had otitis externa, and the difference between them was significant (P<0.05). Ninety-five auditory cerumen specimens were cultured for Malassezia pachydermatis (M. pachydermatis) and analyzed for concentrations of major fatty acids. Although rates of cases positive for M. pachydermatis in both ear pinna shapes were almost the same, i.e. 55.2% in the pendulous group and 53.6% in the erect group, the average total fatty acid level of the pendulous ear group was significantly (P<0.05) higher than that in the erect ear group after dismissing extraordinary levels in the Siberian husky. Isolated M. pachydermatis strains were examined for the effects of fatty acid supplementation on their growth. The majority of the strains utilized fatty acids and grew faster in fatty acid supplemented broth. These results suggest that M. pachydermatis, the predominant causative agent of canine otitis externa, prefers the auditory canal of dogs with lipid-rich earwax and grows fast, but growth strongly depends upon the canine breed.     

Ultrasonographic assessment of maternal cardiac function and peripheral circulation during normal gestation in dogs

The aim of this study was to describe changes in cardiac morphology, systolic function and some peripheral hemodynamic parameters during normal pregnancy in dogs. Twenty healthy bitches, 10 pregnant (PG) and 10 non-pregnant controls (CG), were evaluated every 10 days using echocardiography from day 0 of the estrus cycle to parturition or to day 65 for the PG and CG groups, respectively. Systolic blood pressure (SBP) and uterine artery resistance index (RI) were also assessed. Throughout the study, the shortening fraction and cardiac output increased up to 30% vs. 5% (P<0.01) and 45% vs. 2% (P<0.01) in the PG and CG groups, respectively. In contrast, SBP and RI diminished up to 20% vs. 1% (P<0.01) and 29% vs. 0% (P<0.01) in the PG and CG groups, respectively. In conclusion, a decrease in afterload, an increase in cardiac output and cardiac hypertrophy appear to be the result of the hemodynamic modifications occurring during pregnancy in dogs.     

Effect of herbage depletion on short-term foraging dynamics and diet quality of steers grazing wheat pastures

Two complementary experiments were completed to assess short-term foraging dynamics, diet quality, and ruminal degradation kinetics of herbage consumed by steers with 3 levels of herbage depletion. Experiment 1 was a behavioral study in which 2 ruminally cannulated steers were allocated to grazing scenarios simulating 3 levels of herbage depletion. These treatments included an ungrazed sward (control), as well as medium and high levels of herbage depletion. Grazing scenarios were sampled for sward surface height and amount of green leaf and stem before being grazed. Foraging dynamics were determined through measurements of bite rate, bite depth, eating step rate, eating distance, potential area consumed while grazing, and bites and intake per eating step. Also, quality of potential herbage consumed was estimated from hand-plucked herbage. In Exp. 2, ruminal degradation kinetics of DM for samples of herbage consumed (masticate) by steers during Exp. 1 were assessed in situ using 5 ruminally cannulated steers. The immediately soluble, degraded, and undegraded DM fractions were determined. The DM disappearance rate and lag times were determined from a nonlinear regression model, and the effective degradability of DM was calculated. Herbage depletion resulted in increased eating steps/minute, as well as the potential area harvested while grazing (P < 0.05) and reduced herbage intake/eating step (P < 0.05). Neither the herbage potentially consumed nor the ruminal degradation kinetics was affected by extent of depletion (P > 0.05). Under these experimental conditions, steers adapted their foraging dynamic and were able to sustain diet quality in the short term. These results imply that behavioral adaptations would make diet quality less sensitive to certain levels of herbage depletion.     

Trade communities and their spatial patterns in the German pork production network

The German trade network of pig holdings and related enterprises for the time period of 01 June 2006-31 December 2008 was analyzed. Available data comprised of the entire German trade information with about 121,287 pig premises and their links in the pork production chain (breeders to slaughter houses). During the study period, 330,000 trade connections between premises were recorded. Communities which are large scale structures comprising of premises which are in close trade contact with each other were detected by modularity maximization. Almost 97% of the pig holdings could be assigned to one of nine major communities. Contacts between communities are rare. Trade communities do not only form spatial clusters, but were also associated with specific regions within the territory of Germany. Communities are to some extent separated by 'trade borders', which may impede disease spread. Interestingly, the trade borders often failed to match with administrative borders of the German federal states. This finding is important, because it illustrates the need for new strategies of cross-border disease management strategies.     

Breed differences in the proportional morbidity of testicular tumours and distribution of histopathologic types in a population-based canine cancer registry

Histologically verified tumours submitted to the Norwegian Canine Cancer Register from 1990 to 1998 were studied (n=14,401). The proportion of testicular tumours (n=345) was 2.4%, and the breakdown of histological tumour diagnoses is presented. The frequency of the most common histopathological types was 33% interstitial (Leydig), 26.4% Sertoli and 33.9% seminomas/germ cell tumours. The average age at diagnosis was 10 years, but was significantly lower for Sertoli cell tumours (8.6 years) than for the other tumour types. Following a histopathological re-evaluation, 22.5% of the original tumor diagnoses were modified. Proportional morbidity ratios were calculated and individuals from the breeds Shetland sheepdog and Collie were five times more likely to have testicular tumours than the overall average for the registry. Breed differences in the distribution of histopathologic types were observed. Shetland sheepdog and Collie were most commonly diagnosed with Sertoli cell tumours, while all tumours from Norwegian elkhound in this material were seminomas.