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1.
Danofloxacin, a novel fluoroquinolone antimicrobial drug was evaluated in the treatment of acute bacterial pneumonia in recently housed beef cattle of approximately 300 kg liveweight. The clinical responses of 67 pneumonic cattle treated with danofloxacin were compared with those of 65 cattle treated with oxytetracycline, both treatments being given by intramuscular injection for either three or five days, depending on clinical response. Both treatments resulted in a rapid fall in group mean rectal temperature and improved the clinical condition of the majority of cases. However, in comparison with oxytetracycline, danofloxacin therapy was characterised by significantly fewer treatment days, a higher response rate, significantly better reduction of pyrexia and fewer cattle requiring re-treatment.  相似文献   

2.
Two field efficacy studies, involving a total of 92 naturally infected, pneumonic veal calves, were conducted to compare the efficacy of the β-lactamase inhibitor sulbactam plus ampicillin to ampicillin alone in the treatment of bacterial pneumonia. Cultures from nasal swabs and lung tissue during the 10 or 11 day studies were predominantly ampicillin-resistant Pasteurella multocida. Ampicillin (6.6 mg/kg) or sulbactam-ampicillin (3.3 mg/kg sulbactam + 6.6 mg/kg ampicillin) was injected intramuscularly once daily for either three days or six days. Sulbactam-ampicillin administered once daily for three or six days resulted in lower (P≤0.05) average body temperature with a concomitant clinical improvement (P≤0.05), and produced numerical advantages and/or statistical improvements over ampicillin in mortality, weight gain, and overall response of calves to treatment. The combined mortality for the two studies in the ampicillin and sulbactam-ampicillin treated groups was 43% and 14%, respectively. We concluded that sulbactam-ampicillin was superior to ampicillin in the treatment of ampicillin-resistant bacterial pneumonia in veal calves.  相似文献   

3.
OBJECTIVE: To compare concentrations of danofloxacin, enrofloxacin, and ciprofloxacin in plasma and respiratory tissues of calves treated after challenge with Mannheimia haemolytica. ANIMALS: 75 calves. PROCEDURE: 24 hours after challenge with M. haemolytica, 72 calves with clinical signs of respiratory tract disease were randomly assigned to 1 of 12 equal treatment groups.Three nonchallenged, nontreated calves formed a control group. Challenged calves were treated with danofloxacin (6 and 8 mg/kg, SC) and enrofloxacin (8 mg/kg, SC) once. At 1, 2, 6, and 12 hours after treatment, 6 calves from each treatment group were euthanatized. Antimicrobial drug concentrations were assayed in various specimens. Peak plasma concentration (Cmax)-to-minimum inhibitory concentration (MIC; Cmax-to-MIC) ratios and the area under the concentration versus time curve over a 12-hour period-to-MIC ratios (AUC(12h)-to-MIC) were calculat-ed. RESULTS: Danofloxacin and enrofloxacin had MICs of 0.03 microg/mL for the M. haemolytica challenge isolate. Danofloxacin administered at doses of 6 and 8 mg/kg resulted in numerically higher geometric mean concentrations of danofloxacin in plasma and all respiratory tissues than geometric mean concentrations of enrofloxacin after treatment with enrofloxacin. Geometric mean concentrations of enrofloxacin were numerically higher than geometric mean concentrations of ciprofloxacin metabolite in plasma and almost all respiratory tissues. Danofloxacin and enrofloxacin achieved Cmax-to-MIC ratios >10 and AUC(12h)-to-MIC ratios >125 hours. CONCLUSIONS AND CLINICAL RELEVANCE: When used to treat pneumonic pasteurellosis in calves, danofloxacin and enrofloxacin can be expected to deliver concentration-dependent bactericidal activity against M. haemolytica, the bacteria most commonly associated with bovine respiratory tract disease.  相似文献   

4.
The treatment of an outbreak of acute pneumonia in 50 four- to eight-month-old Friesian and Friesian cross calves is described. At the first visit (day 0) 16 calves received 20 mg/kg bodyweight of oxytetracycline dihydrate intramuscularly and 15 received 10 mg/kg of the macrolide tilmicosin subcutaneously. The remaining 19 in-contact animals were not considered ill enough to be included in the trial and received 20 mg/kg of oxytetracycline dihydrate. The rectal temperature, demeanour, respiratory rate and respiratory effort of each calf was assessed on days 1, 2, 3, 9, 14, 21 and 28, and calves which had not responded were given repeat injections of the same antibiotic. All the calves recovered from the outbreak and of the 19 calves treated strategically, three required a second injection. Among the calves with clinical pneumonia, fewer treatments (P less than 0.01) were required by those treated with tilmicosin. The rectal temperatures of both groups decreased (P less than 0.05) after the first injection, but on day 3 the decrease was greater (P less than 0.05) in the group treated with tilmicosin. Respiratory rates varied widely but respiratory effort was less (P less than 0.05) on day 2 in the calves treated with tilmicosin. When long-acting antibiotic injections are used to treat enzootic pneumonia it is suggested that a second visit should be made on day 3 to assess the animals' response to treatment.  相似文献   

5.
The influence of recombinant bovine interferon gamma (rBoIFN-gamma) treatment on resistance of clinically normal and dexamethasone-treated calves to Haemophilus somnus infection was evaluated. Four groups of 6 calves each were treated with saline solution (controls), dexamethasone (0.04 mg/kg of body weight/for 3 days), rBoIFN-gamma (2 micrograms/kg for 2 days), or dexamethasone and rBoIFN-gamma (aforementioned dosages). All treatments were started 24 hours before intrabronchial challenge exposure with 5 x 10(9) colony-forming units of H somnus. Rectal temperature and WBC count were monitored daily. Two of the dexamethasone-treated calves died of pneumonia 4 days after challenge exposure and were necropsied. All other calves were euthanatized and necropsied 7 days after challenge exposure. All calves had pneumonia of variable intensity. Dexamethasone-treated calves had increased volume of pneumonic lung (P less than 0.05) and increased severity of pneumonia, compared with control calves. Recombinant bovine interferon gamma treatment resulted in reduction in pneumonic lung volume and severity of pneumonia in dexamethasone-treated calves (P less than 0.05), although it did not influence severity of pneumonia in nondexamethasone-treated calves.  相似文献   

6.
The protective effect of an inactivated whole-virion bovine herpesvirus-1 (BHV-1) immunising inoculum, without adjuvant, against viral-bacterial respiratory disease was studied in three experimental treatment groups of five calves each. One group was boosted 14 days after the first vaccination and at this time the second group received their initial inoculation. Seven days later, calves were challenged with BHV-1 in aerosol and four days after this challenge all calves were exposed to Pasteurella haemolytica A1 in aerosol. Among the three groups, differences in rectal temperature responses four days after viral challenge (P less than 0.01) did not relate to protection. However the main response variable, viral-bacterial pneumonia, was reduced in boosted calves (P less than 0.05).  相似文献   

7.
The efficacy of an injectable formulation of danofloxacin (180 mg/ml) in the treatment of naturally occurring bovine respiratory disease was evaluated in field studies on farms in France, Ireland and the United Kingdom. Cattle aged one week to 15 months with clinical respiratory disease were randomly allocated to treatment with 6 mg/kg danofloxacin or 10 mg/kg tilmicosin, administered by a single subcutaneous injection on day 0. A second injection of danofloxacin was administered on day 2, only if predefined clinical criteria were met. Mannheimia haemolytica, Pasteurella multocida and Haemophilus somnus were isolated from pretreatment nasopharyngeal swabs taken on all the farms. After the treatment, there was a more rapid improvement in the clinical response of the 178 animals treated with danofloxacin by day 2 (P < 0.01) than in the 90 treated with tilmicosin. For both treatments, there were similar significant (P < 0.001) reductions in the mean rectal temperature and severity of clinical signs of abnormal respiration and depression, on days 4 and 10 compared with day 0; 78.1 per cent of the animals treated with danofloxacin and 78.5 per cent of those treated with tilmicosin completed the studies. Danofloxacin 18 per cent was clinically safe and as effective as tilmicosin in the treatment of bovine respiratory disease.  相似文献   

8.
OBJECTIVE: To examine effects of danofloxacin and tilmicosin on continuously recorded body temperature in beef calves with pneumonia experimentally induced by inoculation of Mannheimia haemolytica. ANIMALS: 41 Angus-cross heifers (body weight, 160 to 220 kg) without a recent history of respiratory tract disease or antimicrobial treatment, all from a single ranch. PROCEDURE: Radiotransmitters were implanted intravaginally in each calf. Pneumonia was induced intrabronchially by use of logarithmic-phase cultures of M. haemolytica. At 21 hours after inoculation, calves were treated with saline (0.9% NaCl) solution, danofloxacin, or tilmicosin. Body temperature was monitored from 66 hours before inoculation until 72 hours after treatment. Area under the curve (AUC) of the temperature-time plot and mean temperature were calculated for 3-hour intervals and compared among treatment groups. RESULTS: The AUCs for 3-hour intervals did not differ significantly among treatment groups for any of the time periods. Analysis of the mean temperature for 3-hour intervals revealed significantly higher temperatures at most time periods for saline-treated calves, compared with temperatures for antimicrobial-treated calves; however, we did not detect significant differences between the danofloxacin- and tilmicosin-treated calves. The circadian rhythm of temperatures before exposure was detected again approximately 48 hours after bacterial inoculation. CONCLUSIONS AND CLINICAL RELEVANCE: Danofloxacin and tilmicosin did not differ in their effect on mean body temperature for 3-hour intervals but significantly decreased body temperature, compared with body temperature in saline-treated calves. Normal daily variation in body temperature must be considered in the face of respiratory tract disease during clinical evaluation of feedlot cattle.  相似文献   

9.
The efficacy of danofloxacin 18% against naturally occurring Escherichia coli diarrhoea was investigated in calves at seven European sites. Treatment commenced on day 0, with either a single subcutaneous injection of danofloxacin 18% (n=267) at 6 mg/kg repeated on day 2 if required, or reference product containing baquiloprim/sulphadimidine (n=37) or gentamicin (n=98) administered as recommended. E. coli was isolated from 90% to 100% of calves pre-treatment, and the prevalence of serotypes K99 and F41 was 8-46% and 46-92%, respectively. In both treatments, the majority of calves (93.2-93.9%) showed clinical improvement and completed the studies. There were significant reductions for both treatments, in severity of clinical signs on days 4 and 10 compared to day 0 (P<0.0001), and between days 4 and 10 (P<0.05), but no significant differences between treatments (P>0.05). Danofloxacin 18% was clinically safe, and as effective as the reference products in the treatment of E. coli diarrhoea in calves.  相似文献   

10.
Pneumonia caused by Pasteurella (Mannheimia) haemolytica was induced in weaned beef heifer calves, approximately 6 months of age. Calves were treated at 20 h after challenge with therapeutic doses of danofloxacin or tilmicosin. Peripheral blood neutrophils were collected at 3, 24 and 48 h after treatment. The ex vivo effects on neutrophil function, neutrophil apoptosis, and hematological parameters were examined, as was the effect on percentage lung consolidation. Neutrophil function assays included random migration under agarose, cytochrome C reduction, iodination, Staphylococcus aureus ingestion, chemotaxis, and antibody-dependent and antibody-independent cell-mediated cytotoxicity. Apoptosis was determined using a cell death detection kit. Killing was performed at 72 h after treatment. Statistical comparisons were made among the three groups of challenged-treated animals: saline, danofloxacin, and tilmicosin. Comparisons were also made between nonchallenged nontreated animals (NCH) and challenged saline-treated animals. There were no significant differences for any of the neutrophil function assays or neutrophil apoptosis among the challenged-treated groups. This suggests that danofloxacin and tilmicosin have no clinically significant effects on neutrophil function or apoptosis. There were also no significant differences in percentage lung consolidation among the challenged-treated groups. Significant differences were found between the NCH calves and the challenged saline-treated calves in several neutrophil assays, which were attributed to effects of P. haemolytica infection.  相似文献   

11.
Efficacy of tilmicosin in treatment of pulmonary infections in calves.   总被引：3，自引：0，他引：3  
The efficacy of tilmicosin in the treatment of respiratory infections in calves was evaluated. According to a randomised block design, 58 calves with naturally occurring respiratory infections were treated with one of the following products: a single subcutaneous injection of tilmicosin (10 mg/kg liveweight) or daily intramuscular injections of 5 mg lincomycin and 10 mg spectinomycin/kg liveweight, for a minimum of three days. Both treatment groups initially showed similar clinical signs and their initial responses to the treatments were good. However, the tilmicosin treated calves improved more rapidly. Significantly greater improvements (P less than or equal to 0.05) were observed in their demeanour and appetite during the first 10 days after treatment began, and in their respiratory condition between five and 10 days after treatment began.  相似文献   

12.
Tissue cages implanted subcutaneously in calves were infected with Escherichia coli. Twenty-four hours later, the calves were treated either with single doses of 2.5 + 12.5 or 5 + 25 mg/kg trimethoprim (TMP) + sulfadoxine (SDX) or with five doses of 7.5 + 37.5 mg/kg TMP + SDX at 12-h intervals. In addition, one cage in each of three calves in the highest dose group was infected 3 h after initiation of treatment. Untreated calves were kept as controls. Concentrations of TMP and SDX in plasma and tissue cage fluid (TCF) and counts of viable bacteria in TCF were determined. In the highest dose group, concentrations of TMP in TCF remained above the minimum inhibitory concentration of the test strain for 94-101 h and peak to minimum inhibitory concentration (MIC) ratio was close to 10. In spite of this, an effect of treatment was noted only in cages infected after initiation of treatment. In vitro studies and analysis of thymidine content in serum and TCF from calves suggest that levels of thymidine in TCF are high enough to antagonize the antibacterial effect of TMP. The results indicate that soft tissue infections in secluded infection sites of calves are refractory to treatment with TMP + SDX.  相似文献   

13.
Age-related changes in the absorption and distribution patterns of trimethoprim/sulfadiazine were studied following oral or subcutaneous administration of 15 mg/kg of the drug combination in calves. Following oral administration, the time course of trimethoprim/sulfadiazine appearance and dissipation in serum, synovial fluid and urine was followed for periods up to 48 hours in calves one day, one week and six weeks of age. The profiles of drug appearance-disappearance in these body fluids were also determined after subcutaneous administration in seven week old calves. The peak serum and synovial fluid levels of trimethoprim/sulfadiazine achieved following oral administration were substantially lower with increasing maturation. In ruminating (six and seven week old) calves, subcutaneous or oral administration of the combination led to high serum levels of sulfadiazine but little or no serum trimethoprim was detected in animals at this age. The data indicate that, while therapeutic concentrations and optimum ratios of the drugs may be achieved for extended time periods in neonatal life, this dosage is unable to produce optimum serum and synovial fluid concentrations as the calves mature.  相似文献   

14.
Fifteen three- to six-month old Hereford-cross calves were divided into three groups. The first group was inoculated with bovid herpersvirus 1 (Strain 108), the second with a commercial intranasal vaccine against bovid herpesvirus 1 and the third group acted as controls. At least three weeks after vaccination, all calves were weaned, placed in an environmental chamber at 25.0 degrees C (days) and -13.3 degrees C (nights) and challenged with an aerosol of bovid herpesvirus 1 followed four days later by an aerosol of Pasteurella haemolytica. All surviving calves were sacrificed four days after the second aerosol. None of the calves inoculated with bovid herpesvirus 1 virus or the commercial vaccine developed a generalized pneumonia, although there were one or two nodules (4--8 mm diameter) in two of the calves given the commercial vaccine. Four of the five control calves had extensive lobar pneumonia at necropsy, two of the five died from the disease. Details of the clinical, pathological, bacteriological, virological and some of the serological findings are reported.  相似文献   

15.
Previous research has demonstrated that 4-ipomeanol toxicosis can enhance the severity of para-influenza virus-induced pneumonia in mice. The objectives of this study were to determine whether calves are susceptible to 4-ipomeanol-induced enhancement of parainfluenza type 3 viral pneumonia and to determine whether 4-ipomeanol alters pulmonary replication of parainfluenza virus. Male Holstein calves were injected with either 4-ipomeanol (3 mg/kg) or vehicle (polyethylene glycol) 3 days prior to intratracheal inoculation with either parainfluenza virus or sham inoculum of culture medium. Calves in the four treatment groups (ipomeanol-parainfluenza, ipomeanol-medium, vehicle-parainfluenza, and vehicle-medium) were necropsied at 5 days after inoculation with parainfluenza virus or medium. The lungs were studied by correlated methods of light and electron microscopy, digitizing morphometry and pulmonary lavage to quantitate the severity of pneumonia. Pulmonary viral titers were determined, and viral antigen was identified in the lung by immunoperoxidase technique. The calves in the ipomeanol-virus treatment group had over a 9-fold higher (P less than 0.05) volume density of virus-induced interstitial pneumonia than did the calves in the other three treatment groups. This 4-ipomeanol-enhanced viral pneumonia was associated with significantly greater (P less than 0.05) numbers of pulmonary macrophages and neutrophils in the lavage fluid and higher (P less than 0.05) pulmonary titers of pulmonary infectious parainfluenza virus. Four-ipomeanol-enhanced viral pneumonia was characterized in part by extensive hyperplasia of type II alveolar epithelial cells and by dense aggregates of macrophages and neutrophils in alveolar spaces and interalveolar septa. The results indicate that 4-ipomeanol exacerbates interstitial pneumonia in calves induced by bovine parainfluenza type 3 virus.  相似文献   

16.
Survival to maturity and age at first calving were studied in heifer calves from 34 randomly selected Holstein dairy farms in southwestern Ontario. Calves were divided into cohorts on the basis of treatment for pneumonia, scours, other diseases, or no treatments, during the first 90 days of life. An effect of pneumonia and scours together, over and above the effects of each disease alone, was assessed by means on an interaction term in the statistical analyses. Heifers which had been treated for pneumonia during the first three months of life were 2.5 times more likely to die after 90 days of age than heifers which had not been treated for pneumonia, after controlling for the farm effect. Heifers with a calfhood history of being treated for scours were 2.5 times more likely to be sold for dairy purposes than other calves. Heifers which had been treated for scours were 2.9 times more likely to calve after 900 days of age than other heifers, after controlling for the farm effect.  相似文献   

17.
Two hundred forty five market-stressed bull and steer calves (205 +/- 14 kg) were received in January and September 2001 to determine the response of acute-phase proteins to dietary energy and starch concentrations and to determine whether acute-phase proteins could be used as a diagnostic or prognostic tool for calves affected by bovine respiratory disease. On arrival, calves were randomly assigned to one of two dietary energy levels (0.85 or 1.07 Mcal of NEg/kg of DM) and one of two dietary starch levels (34 or 48% of dietary ME from starch; n = 5 pens/treatment). All calves were weighed, and plasma and serum samples were collected from a subset of animals (n = 6 calves/pen; 30 calves/treatment) on d 0, 7, 14, 28, and 42 of the receiving period. This subset of calves (n = 120) was used for all subsequent analyses. Concentrations of fibrinogen (Fb), haptoglobin (Hp), and serum amyloid-A (SaA) were determined. In addition, samples were collected from the subset of calves when they received medical treatment and 7 d following treatment to measure serum concentrations of Hp and SaA. Serum concentrations of Fb, Hp, and SaA did not differ among dietary treatments, but decreased (P < 0.03) as day of the receiving period increased. Fibrinogen (P < 0.001) and the ratio of Fb:total blood protein were greater (P < 0.003) in calves treated multiple times than in calves never treated or treated once for bovine respiratory disease. In addition, on d 0 and 7, Hp concentration increased (antimicrobial treatment x day interaction, P < 0.03) as the number of antimicrobial treatments increased, and was greater on d 14 and 28 in calves treated multiple times than in calves never treated or treated once. Haptoglobin concentration was greater (P < 0.05) in calves on medical treatment days compared with recovery days (7 d after medical treatment). Although diet seemed to have little effect on acute-phase protein response, these results suggest that haptoglobin may be useful as a diagnostic tool to make management decisions regarding treatment protocols for calves with bovine respiratory disease.  相似文献   

18.
Three experiments were performed to evaluate the immunogenic potency of a soluble fraction of Pasteurella haemolytica against pneumonic pasteurellosis in calves. A soluble antigen was extracted by a 2.5% saline solution from P. haemolytica. Weaned Holstein bull calves, seronegative for infectious bovine rhinotracheitis virus ( IBRV ) and the pasteurella antigen, were vaccinated either by repeated subcutaneous (SC) vaccination, or by exposure 3 times to the aerosol of P. haemolytica antigen. Challenge exposure to aerosol of P. haemolytica was preceded by infection with IBRV , or in experiments 2 and 3, the virus exposures were combined with a stress treatment. The lung lesions were examined at necropsy 3 to 8 days post infection. In the first experiment, all the vaccinated calves produced specific antibody response to the pasteurella antigen, and none of the calves including controls showed significant lesions in the lung. In the second experiment 2 aerogenically vaccinated calves had no lesions. One of the two SC-vaccinated calves had mild consolidated lesions. Two control calves, one of which died 3 days following the challenge, developed severe fibrinous pneumonia with consolidation of 50% or more of the lung surfaces. P. haemolytica was isolated only from the 2 control animals. In the third experiment, 2 of the 3 control calves developed moderate to severe consolidation, but P. haemolytica was isolated only from one of them. Two of the three aerosol-vaccinated calves also developed significant lesions and one of them yielded the bacteria from the lung. Three SC-vaccinated calves had slight lesions and the organism was not isolated from their lungs. The results did not consistently indicate an immunogenic potential of the soluble antigen against P. haemolytica-related pneumonia. The effect of stress on the pathogenesis of bovine viral pneumonia and correlation between pneumonic lesions and antibacterial resistance in situ are discussed.  相似文献   

19.
Lungworm-infected seeder calves were used on four 1.41 ha paddocks to ensure that groups of 11 calves would be exposed to a heavy challenge with Dictyocaulus viviparus. By the 39th day after turnout there was a serious episode of respiratory disease and a diagnosis of parasitic bronchitis was confirmed by post mortem and faecal examination. One group of trial calves was treated with netobimin administered in the drinking water at 2.8 mg/kg/day for seven consecutive days; another group received the same treatment supplemented with flunixin meglumine at 2.2 mg/kg/day for three days; a third group was given a single oral dose of 7.5 mg netobimin/kg; only emergency treatments were given to calves in the control group. The clinical response to the drinking water treatments was highly satisfactory and better than the response to the single oral treatment.  相似文献   

20.
The effect of subclinical levels of mycotoxin T-2 on the cells of the bovine immune system was investigated in two in vivo experiments. In experiment 1, five calves were orally dosed with 0.3 mg/kg/day of T-2 toxin for 56 days and five calves were pair fed controls. The neutrophil function as measured by nitroblue tetrazolium reduction was reduced in the mycotoxin treated calves. The cutaneous reaction to intradermally injected phytohemagglutinin was reduced in the T-2 toxin treated calves. B-cell (SIg+) numbers increased slightly, but T-cell (PNA+) numbers were not affected during the experimental period. In the second experiment, six calves were given 0.5 mg/kg/day T-2 toxin orally for 28 days and six calves were pair fed controls. B-cell numbers and the response of a B-cell enriched fraction to phytohemagglutinin increased after toxin administration. T-cell numbers and the response of a T-cell enriched fraction and the whole mononuclear cell population to phytohemagglutinin was reduced only on day 19 posttoxin administration. The in vitro (T-2 toxin) exposure of the mononuclear cell population, B-cell enriched, or T-cell enriched fraction reduced their lymphoblastic response to mitogens. A 50% reduction was induced by as little as 1.4 ng/mL of T-2 toxin.  相似文献   

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