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Classical methods for detection of Chlamydophila species, and of antibodies against these agents, have indicated that these bacteria are highly prevalent in cattle and associated with numerous disease conditions. These methods demonstrated acute Chlamydophila-induced diseases such as epizootic bovine abortion, as well as worldwide variable, but generally high, Chlamydophila seroprevalence. However, it was impossible to consistently detect the low levels of these organisms which were suspected to be present in endemic infections. Application of highly sensitive real-time PCR and ELISA methods for detection of Chlamydophila spp. DNA and of antibodies against Chlamydophila spp., respectively, in a series of prospective cohort studies revealed a high prevalence of Chlamydophila spp. genital infections in female calves (61%) and adult heifers (53%). These infections were acquired by extragenital transmission in the first weeks of life, and infection frequency was increased by crowding of the animals. A challenge study demonstrated that infection with C. abortus resulted in decreased fertility of heifers. The experimental use of a C. abortus vaccine provided evidence for immunoprotection against C. abortus-induced suppression of bovine fertility. The results of these investigations suggest that bovine Chlamydophila infection should be viewed more as pervasive, low-level infection of cattle than as rare, severe disease. Such infections proceed without apparent disease or with only subtle expressions of disease, but potentially have a large impact on bovine herd health and fertility. 相似文献
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Singh V Amarpal Kinjavdekar P Aithal HP Pratap K 《Veterinary research communications》2005,29(1):1-18
The efficacy of ketamine and bupivacaine in enhancing the epidural analgesia induced by medetomidine was evaluated in 10 buffalo calves utilized repeatedly after a gap of 10 days so that each drug combination was tested in 4 randomly selected animals. In group A, medetomidine (15 microg/kg), in group B ketamine (2.0 mg/kg), in group C bupivacaine (0.125 mg/kg), in group D medetomidine and ketamine (15 microg/kg and 2.0 mg/kg), and in group E medetomidine and bupivacaine (15 microg/kg and 0.125 mg/kg) was administered epidurally. Onset of analgesia was significantly earlier in animals of groups B and D compared to the animals of groups A, C and E. Medetomidine alone or in combination with ketamine/bupivacaine produced complete analgesia of the tail, perineum, inguinal region and upper parts of hind limbs. Ketamine produced a very short duration of complete analgesia at the tail and perineum. Bupivacaine alone produced only mild to moderate analgesia. Both ketamine and bupivacaine prolonged the duration of analgesia. Motor incoordination was mild to moderate in animals of all the groups, but animals remained standing throughout the period of observation. Animals of groups A, D and E showed mild to moderate sedation during the observation period. Ruminal movements decreased nonsignificantly in animals of groups A and E. Mild salivation was observed in animals of all the groups except group C. Significant decrease in heart rate (HR) was recorded after epidural administration of medetomidine or bupivacaine; however, ketamine caused short duration of tachycardia. The administration of ketamine with medetomidine caused lesser decrease in HR compared to medetomidine alone or in combination with bupivacaine. Significant fall in respiratory rate (RR) was recorded after epidural administration of medetomidine or bupivacaine alone, but an increase in RR was recorded after ketamine administration. The fall in RR was less pronounced in animals in which medetomidine was used with ketamine compared to the animals in which medetomidine was used alone or in combination with bupivacaine. Mean arterial pressure (MAP) decreased and central venous pressure (CVP) increased significantly after epidural administration of medetomidine in combination with ketamine or bupivacaine. The ECG changes included tall T wave, QS pattern, RS pattern and ST elevation and heart blocks at different intervals, which were more frequent and pronounced in animals given bupivacaine with medetomidine. It can be concluded that epidural administration of medetomidine can produce complete analgesia of the tail, perineum, inguinal region and upper hind limbs in buffaloes. However, significant depression of cardiovascular parameters was recorded. Administration of ketamine along with medetomidine resulted in significantly early onset and slightly longer duration of analgesia with lesser cardiopulmonary side-effects compared to medetomidine alone or medetomidine with bupivacaine. Addition of ketamine to medetomidine thus seems to be useful for producing epidural analgesia; however, addition of bupivacaine failed to provide any advantage over medetomidine alone. 相似文献
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Anne-Kathrin Schink Kristina Kadlec Tomasz Hauschild Geovana Brenner Michael Julia C. Dörner Carolin Ludwig Christiane Werckenthin Hans-Robert Hehnen Bernd Stephan Stefan Schwarz 《Veterinary microbiology》2013
In this study, 908 bacterial pathogens from defined infections of dogs and cats were tested for their susceptibility to the novel fluoroquinolone pradofloxacin, which was approved in 2011 for use in cats and dogs. Most of the bacteria tested (Staphylococcus aureus, Staphylococcus pseudintermedius, Escherichia coli, β-haemolytic streptococci, Pasteurella multocida and Bordetella bronchiseptica) exhibited low pradofloxacin MIC90 values of ≤0.25 μg/ml. Solely Proteus spp. and Pseudomonas aeruginosa had higher MIC90 values of ≥4 μg/ml. Only six (3.4%) of 177 S. pseudintermedius and 12 (5.3%) of 227 E. coli isolates showed pradofloxacin MICs of ≥2 μg/ml. Analysis of the quinolone resistance determining regions of the target genes identified double mutations in GyrA that resulted in amino acid exchanges S83L + D87N or S83L + D87Y and single or double mutations in ParC that resulted in amino acid exchanges S80I or S80I + E84G in all 12 E. coli isolates. The six S. pseudintermedius isolates exhibited amino acid exchanges S84L or E88K in GyrA and S80I in GrlA. Comparative analysis of the MICs of pradofloxacin and the MICs determined for enrofloxacin and its main metabolite ciprofloxacin, but also marbofloxacin, orbifloxacin, difloxacin and ibafloxacin was conducted for the target pathogens S. pseudintermedius, E. coli and P. multocida. This comparison confirmed that pradofloxacin MICs were significantly lower than those of the other tested fluoroquinolones. 相似文献
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An inactivated vaccine containing BVDV I and II strains (PT810; BVDV I, and 890; BVDV II) and using different adjuvants and antigen dosages was tested in a cattle challenge model. Groups of six healthy, seronegative cattle were vaccinated twice with a low dose (10(6.6) TCID(50) PT810 and 10(7.2) TCID(50) 890) vaccine with the adjuvant Bay R1005 or a high dose (10(7.8) TCID(50) PT810 and 10(8. 2) TCID(50) 890) vaccine with two different adjuvants (Bay R1005 or Polygen). Thirty-eight days after the second vaccination, immunised animals (n=18) and non-vaccinated control animals (n=3) were challenged intranasally with 10(6) TCID(50) BVDV strain PT810. For a period of 16 days, virus was isolated from blood leukocytes and nasal swabs, and neutralising antibody titres were determined.The induction of antibodies following immunisation was strongly dependent on the antigen dosage in the vaccine. The high dose formulation induced high serum neutralising antibody titres against both genotypes of up to 32000 after the second immunisation. Animals with neutralising antibody titres >512 (n=14) did not show any marked leukopenia after challenge and only very little or no virus could be isolated from blood leukocytes and/or nasal swabs when compared to control cattle. Furthermore, some of these animals did not show any boost of neutralising or even NS3-specific antibodies, which renders viral replication unlikely and thus would prevent infection of the fetus. Both adjuvants (Bay R1005 or Polygen) were similarly efficient and induced nearly identical antibody responses. In contrast, four of the six low dosage vaccinates had a marked leukopenia and viraemia as well as detectable nasal virus shedding for several days.We conclude that the selected strains and the system of vaccine preparation with high BVDV antigen dosages and highly efficient new adjuvants provide an effective means of protection against BVDV I infections. Investigations to demonstrate the protection against BVDV II infections, the duration of immunity and the ability of fetal protection by using the high dose vaccine in a fetal challenge model will follow. 相似文献
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