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Clinical signs and their association with herd demographics and porcine reproductive and respiratory syndrome (PRRS) control strategies in PRRS PCR-positive swine herds in Ontario Texte intégral
2010
Young, Beth | Dewey, Cate | Poljak, Zvonimir | Rosendal, Thomas | Carman, Susy
The purposes of this study were to describe the clinical signs observed in PRRS positive herds during a porcine reproductive and respiratory syndrome (PRRS) outbreak in Ontario and to determine associations between these clinical signs and herd demographics and PRRS control strategies. All PRRS polymerase chain reaction-(PCR)-positive submissions to a diagnostic laboratory between September 1, 2004 and August 31, 2007 were identified (n = 1864). After meeting eligibility requirements and agreeing to voluntary study participation, producers from 455 of these submissions were surveyed for information on clinical signs observed in their herds, herd demographics, and PRRS control strategies used in their herds at the time that the PCR-positive samples were taken. Larger herd size was associated with an increased risk of reporting abortion, weakborn piglets, off-feed sows, and sow mortality in sow herds, and with an increased risk of reporting mortality in finishing herds. When disease control strategies were examined, use of a commercial PRRS vaccine in sows and gilts was associated with a decreased risk of reporting weakborn pigs and high pre-weaning mortality, while the use of serum inoculation in breeding animals was associated with an increased risk of reporting off-feed sows and sow mortality. Providing biofeedback of stillborn/mummified piglets, placenta or feces to gilts was associated with an increased risk of reporting respiratory disease and mortality in finishing pigs while all-in/all-out flow in farrowing rooms was associated with an increased risk of reporting sow mortality and weakborn piglets.
Afficher plus [+] Moins [-]Assessment of 2 Salmonella enterica serovar Typhimurium-based vaccines against necrotic enteritis in reducing colonization of chickens by Salmonella serovars of different serogroups Texte intégral
2010
Jiang, Yanfen | Kulkarni, Raveendra R. | Parreira, Valeria R. | Poppe, Cornelius | Roland, Kenneth L. | Prescott, John F.
This study assessed the protective efficacy of oral vaccination with 2 experimental attenuated Salmonella Typhimurium-vectored vaccines for necrotic enteritis in protecting chickens against intestinal colonization by common serovars of Salmonella belonging to the 4 major serogroups affecting chickens. Birds were vaccinated orally with 1 × 108 colony-forming units (CFU) of 1 of the vaccine strains χ9241 and χ9352, which express a plasmid-encoded partial recombinant hypothetical protein gene (tHP) of Clostridium perfringens, at days 1 and 7 of age, and then were challenged at 14 d of age with 106 CFU of Salmonella serovars Anatum, Enteritidis, Heidelberg, Kentucky, or Typhimurium (representative serovars of serogroups B, C, D, and E). Birds were necropsied at 4 wk of age, and samples were collected to determine reduction in tissue and intestinal colonization. The chickens vaccinated with χ9241-tHP showed reduced colonization by Salmonella Enteritidis (serogroup D) and by Salmonella Heidelberg and Salmonella Typhimurium (serogroup B) compared with the control birds. No reduction in colonization was observed in the chickens vaccinated with χ9352-tHP. There was an association between the efficacy of these vaccine strains in protecting against necrotic enteritis, assessed on an earlier occasion, and their efficacy in protecting against Salmonella colonization. Thus, the choice of an attenuated Salmonella Typhimurium vaccine vector for delivery of heterologous antigens to chickens should be based partly on the vaccine’s value in protecting against colonization by serovars within serogroups B and D. Such vectors would have the additional benefit of reducing colonization of important Salmonella serovars.
Afficher plus [+] Moins [-]Effect of Plocamium cartilagineum aegypticus on Boophilus annulatus Texte intégral
2010
Rania A. Abd El-Wahab
Halogenated monoterpenes isolated from the red alga Plocamium cartilagineum aegypticus , proved their efficacy as acaricide. Both of Violacene and Mertensene, were adulticides with LC50's, 340.56 ppm and 759.23ppm, respectively, against the cattle tick; Boophilus annulatus adult females. Moreover, they can be used as ovicides. Violacene and Mertensene caused reduction in the hatchability by 96.77% and 95% respectively. Clinico-pathological studies were carried out and showed that Plocamium extract is safe to the host and none-target animals.
Afficher plus [+] Moins [-]Comparative ultrastructure of fibrin networks of a dog after thrombotic ischaemic stroke Texte intégral
2010
Pretorius, Etheresia(University of Pretoria Department of Anatomy Faculty of Health Sciences) | Windberger, Ursula B.(Medical University Vienna Center for Biomedical Research) | Oberholzer, Hester M.(University of Pretoria Department of Anatomy Faculty of Health Sciences) | Auer, Roland E. J.(University of Pretoria University of Pretoria Biomedical Research Centre)
A cerebrovascular accident or stroke is a rare condition in dogs, but previous studies suggest that it is now increasingly being recognised. Platelets and fibrin networks are involved in haemostasis, which is disrupted during a thrombotic event. In this study we investigate the ultrastructure of the fibrin networks of a dog that had suffered ischaemic stroke, following suspected thrombo-embolism from clots that became dislodged during catheter maintenance (flushing with heparinised saline) 2 days after carotid artery catheter insertion. Fibrin networks of blood samples that were collected immediately after the stroke, 15 min after treatment with streptokinase and 24 h after treatment, were studied. The results were compared to those of two control dogs. During a stroke, fibrin morphology changes to form a thick, matted layer. Post-treatment ultrastructure shows that the fibrin morphology returns to that comparable to controls. Our results show that during thrombotic risk, fibrin network morphology changes visibly and reduces the fibrinolytic activity of the coagulation system.
Afficher plus [+] Moins [-]Changes of very low-density lipoprotein concentration in hepatic blood from cows with fasting-induced hepatic lipidosis Texte intégral
2010
The purpose of this study was to evaluate changes of very low-density lipoprotein (VLDL) components in hepatic blood (HB) from 5 nonlactating nonpregnant cows fasted from days 0 to 3 and subsequently refed to day 10 and, in addition, to assess those of other lipoproteins. Increased phospholipid concentrations in each lipoprotein after the start of fasting suggested their availability for the surface lipids of lipoproteins. Although the VLDL-triglyceride (TG) concentration in HB from all cows increased on day 1, the value on day 4 became similar to that on day 0. However, the concentration on day 10 was significantly increased. In all cows, the decreased ratio of the VLDL-TG concentration in HB to the non-esterified fatty acids (NEFA) concentration in portal blood (PB) on day 4 appeared to reflect relatively decreased secretion of TG as VLDL by NEFA excessively mobilized to the liver via PB. The markedly increased ratio on day 10 was considered to contribute to the improvement of hepatic lipidosis.
Afficher plus [+] Moins [-]Anti-obesity effects of onion juice in high fat diet-induced obese rats
2010
Kang, W.Y., Jeju National University, Jeju, Republic of Korea | Kim, M.Y., Jeju National University, Jeju, Republic of Korea | Jin, J.Y., Jeju National University, Jeju, Republic of Korea | Yang, H.K., Jeju National University, Jeju, Republic of Korea | Hong, H.J., Jeju National University, Jeju, Republic of Korea | Kim, D.G., Jeju National University, Jeju, Republic of Korea | Han, C.H., Jeju National University, Jeju, Republic of Korea | Lee, Y.J., Jeju National University, Jeju, Republic of Korea
This study investigated the effects of onion juice on the serum lipid components and blood pressure in obese rats fed high fat diets. Thirty-nine of Sprague-Dawley rats were divided into six groups, and were treated for 8 weeks: (1) normal diet (ND); (2) high fat diet (HFD); (3) HFD for first 4 weeks and high fat diet with 40% onion juice for the last 4weeks (H-H+O); (4) HFD with 40% onion juice for 8 weeks (H+O); (5) HFD for first 4 weeks and ND for the last 4 weeks (H-N); (6) HFD for first 4 weeks and ND with 40% onion juice for the last 4 weeks (H-N+O). The rates of increasing body weight were reduced in H+O and H-H+O groups compared with HFD group. The levels of triglyceride, low density lipoprotein-cholesterol and total cholesterol in blood serum were significantly decreased in the H+O and H-H+O groups compared with the HFD group. Administration of onion reduced the size of adipocyte, steatosis, and serum hyperlipidemia in obese rats fed HFD. Moreover, the antihypertensive effects of onion were observed in obesity rat fed HFD. Overall results suggest that onion reduces the serum lipid components and improves hypertension in obese rat fed HFD.
Afficher plus [+] Moins [-]Comparison of linear and non-linear equation for the calibration of roxithromycin analysis using liquid chromatography/mass spectrometry
2010
Lim, J.H., Chungnam National University, Daejeon, Republic of Korea | Yun, H.I., Chungnam National University, Daejeon, Republic of Korea
Linear and non-linear regressions were used to derive the calibration function for the measurement of roxithromycin plasma concentration. Their results were compared with weighted least squares regression by usual weight factors. In this paper the performance of a non-linear calibration equation with the capacity to account empirically for the curvature, y = ax∨b + c (b not equal to 1) is compared with the commonly used linear equation, y = ax + b, as well as the quadratic equation, y = ax²+ bx + c. In the calibration curve (range of 0.01 to 10 ㎍/mL) of roxithromycin, both heteroscedasticity and nonlinearity were present therefore linear least squares regression methods could result in large errors in the determination of roxithromycin concentration. By the non-linear and weighted least squares regression, the accuracy of the analytical method was improved at the lower end of the calibration curve. This study suggests that the non-linear calibration equation should be considered when a curve is required to be fitted to low dose calibration data which exhibit slight curvature.
Afficher plus [+] Moins [-]Sensitivity analysis of serological tests for detection of disease in cattle
2010
Lee, S.J., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Moon, O.K., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Pak, S.I., Kangwon National University, Chuncheon, Republic of Korea
Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.
Afficher plus [+] Moins [-]Transjugular occlusion of patent ductus arteriosus using an Amplatz canine ductal occluder in a Cocker spaniel dog
2010
Choi, R., Kangwon National University, Chuncheon, Republic of Korea | Hyun, C.B., Kangwon National University, Chuncheon, Republic of Korea
A 5-year-old female Cocker spaniel dog (body weight 7.0 kg) was presented with primary complaints of exercise intolerance and loud precordial thrill which was noticed since she was a puppy. Physical examination revealed a grade Ⅴ/Ⅵ continuous murmur over the maximal point of the left basal area, bounding femoral pulse, but no differential cyanosis. Tall R waves were detected in electrocardiogram, suggesting left ventricular enlargement. Diagnostic imaging studies showed enlarged left ventricle, bulged descending aorta (dAo), markedly dilated right pulmonary artery, and continuous shunt flow between the dAo and main pulmonary artery. Based on these findings, the dog was diagnosed as left to right shunted patent ductus arteriosus (PDA). The patent ductus arteriosus was treated by lodging a PDA duct occluder via the transvenous approach. Clinical signs were markedly improved after the ductal occlusion, the shunt flow was mildly persistent. The case presented is the first case of PDA occluded by the PDA duct occluder via the transvenous approach in a small breed of dog. Although the residual shunt flow was mildly persisted, the dog was clinically normal without detectable murmurs.
Afficher plus [+] Moins [-]Mycobacterium avium subsp. avium infection in a lineolated parakeet (Bolborhynchus lineola)
2010
Lee, S.Y., Konkuk University, Seoul, Republic of Korea | Yoo, J.H., Konkuk University, Seoul, Republic of Korea | Yoon, J.W., Chung-Ang University College of Medicine, Seoul, Republic of Korea | Kim, D.Y., University of Missouri, Columbia, MO, USA | Cho, H.S., University of Missouri, Columbia, MO, USA | Park, C., University of California, Davis, CA, USA | Park, H.M., Konkuk University, Seoul, Republic of Korea
A 2-year-old lineolated parakeet (Bolborhynchus lineola) was presented with abdominal distention and respiratory distress for two months. The bird was poorly fleshed and the liver was enlarged on coelomic palpation. Plain and contrast radiographic examinations exhibited hepatomegaly and distended intestinal loop, which compromised the air sacs. Multifocal yperechogenecity was observed in the liver on ultrasonography. Postmortem gross examination revealed hepatomegaly with numerous pinpoint tan foci in the hepatic parenchyma and distended small intestine filled with adult ascarids. Microscopically, granulomatous hepatitis and enteritis infected by intrahistiocytic acid-fast bacilli were evident. Polymerase chain reaction indicated that the acid-fast bacilli were Mycobacterium avium subsp. avium.
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