In vitro susceptibility of avian Escherichia coli and Pasteurella multocida to danofloxacin and five other antimicrobials.

The in vitro susceptibility of Escherichia coli and Pasteurella multocida isolated from poultry was determined to danofloxacin, a novel fluoroquinolone, and five other commonly used antimicrobials. A total of 1737 E. coli field isolates and 107 P. multocida isolates were tested by veterinary diagnostic laboratories in Europe, Japan, South Africa, and North America during the period 1989-91. The antimicrobial susceptibility of these isolates was determined using the Sensititre broth microdilution technique. The minimum inhibitory concentrations (MIC) of danofloxacin, furaltadone, lincomycin, oxytetracycline, spectinomycin, and trimethoprim:sulfamethoxazole that prevented growth of 90% of the bacteria were 0.25 > 64, > 64, > 64, > 128, and > 16 micrograms/ml, respectively, against E. coli isolates and 0.25, 64, 64, 16, 128, and 8 micrograms/ml, respectively, against P. multocida isolates. Danofloxacin demonstrated considerable in vitro potency against these important poultry pathogens, many of which showed extensive resistance to the other antimicrobials tested.

Efficacy of a novel sustained release anthelmintic device in preventing parasitic gastroenteritis in first-season calves.

The efficacy of the first of a new generation of intraruminal devices for cattle, the morantel sustained release trilaminate, was assessed in two field trials. In each trial the animals were divided into a control group and a treated group. The device was administered to each calf before turn out in the spring and the reduction of gastrointestinal parasitism resulted in a substantial reduction in the level of pasture contamination with infective helminth larvae later in the season. Compared with the control calves the treated calves had a 94 per cent reduction of worm burdens acquired over the entire grazing season in the first trial, despite the controls being treated for clinical disease in September. In the second trial four anthelmintic treatments were administered to the control calves during the grazing season, but nevertheless a 64 per cent reduction of worm burdens in the treated group compared to the control group was recorded. The control of parasitic infection by the sustained-release devices resulted in mean weight gain advantages of 28.3 kg and 34.7 kg by the treated animals in the first and second trials respectively.

Field trials with cefoperazone in the treatment of bovine clinical mastitis.

A single dose of 250 mg cefoperazone in an oil based suspension infused into bovine quarters suffering from clinical mastitis resulted in an overall clinical cure of 82 per cent in 597 cases, as assessed by veterinarians in four countries (Sweden, Denmark, France and the United Kingdom). Of those cases for which adequate bacteriological data were available 69 per cent of 434 cases were cured. There were no reports of adverse reactions following therapy of an affected quarter. The introduction of single dose treatment represents an advance in mastitis therapy as it offers a simpler and shorter treatment than most present day mastitis therapeutics when used according to recommendations.

Antimicrobial susceptibility of Actinobacillus pleuropneumoniae, Pasteurella multocida and Salmonella choleraesuis isolates from pigs.

The in vitro susceptibility of 839 isolates of Actinobacillus pleuropneumoniae, 969 isolates of Pasteurella multocida and 104 isolates of Salmonella choleraesuis from pigs to the fluoroquinolone danofloxacin, and eight other commonly used antimicrobial drugs was determined by veterinary diagnostic laboratories in Europe, Japan, South Africa and North America between 1989 and 1991, by using a broth microdilution technique. The minimum inhibitory concentrations of danofloxacin, amoxycillin, ceftiofur, erythromycin, gentamicin, lincomycin, oxytetracycline, spectinomycin and trimethoprim:sulphamethoxazole (ratio 1:19) that prevented the growth of 90 per cent of the bacteria were 0.125, < or = 0.5, < or = 0.125, 8, 8, 32, 32, 64 and < or = 0.25 microgram/ml for A pleuropneumoniae, 0.06, 1, < or = 0.125, 8, 4, 64, 8, 32 and 8 micrograms/ml for P multocida, and 0.125, > 64, < or = 1, > 64, 1, > 64, > 64, 64 and < or = 0.25 microgram/ml for S choleraesuis. These data confirm the high in vitro potency of danofloxacin against field isolates that show significant resistance to several other antibacterial drugs.

A field study comparing a pregrazing treatment with the morantel sustained release bolus with a strategic deworming program in first year grazing cattle.

A field trial was designed to compare the efficacy of a pregrazing treatment with a morantel sustained release bolus and two strategic treatments of levamisole in the prevention and control of gastrointestinal parasitism in first year grazing cattle. The infection of calves, pasture contamination and the subsequent effects on performance were recorded.