Lhermie Guillaume

Abstract :

The use of antibiotics in veterinary medicine may lead to selection of resistant bacteria, potentially transmissible to humans. Our study aimed at assessing under field conditions the effectiveness of early treatment of bovine respiratory disease (BRD) with a reduced dose of marbofloxacin, and its impact on (i) the amount of antibiotics consumed, and (ii) the selection of resistant commensal bacteria in the digestive tract. Preliminary experimental studies (in vitro and in animal models - mice and calf) allowed to validate the effectiveness of a reduced dose and to determine its conditions of use. During the field study, cattle were monitored using devices measuring their ruminal temperature, which increase constitutes an early sign of disease. In comparison with the administration of the 10 mg/kg dose recommended by the manufacturer, a unique early treatment with2 mg/kg marbofloxacin, before the onset of clinical signs, did reduce overall antibiotic consumption at the batch or farm level, despite an increase in the number of administered treatments. Whatever the dose, the impact of marbofloxacin on selecting commensal bacteria proved limited in calves and young cattle. Finally, our work highlights through the case of BRD, the possible reduction of the use of antibiotics in bovine medicine. To achieve this, the development of a veterinary precision medicine, combining monitoring and diagnosis tools with adjusted medication protocols, should be encouraged.

Key words :

Cattle, bovine respiratory disease, fluoroquinolone, early treatment, decreased regimen, antimicrobial resistance, precision medicine