Microbiology and pharmacology of enrofloxacin in cattle

Enrofloxacin is the first third-generation fluoroquinolone specifically developed for use in veterinary medicine. It is approved worldwide for use in dogs and cats and, for food animals outside the U.S. and Canada. Enrofloxacin has a wide spectrum of antimicrobial activity, is rapidly bactericidal, is active at very low concentrations, and shows no plasmid-mediated resistance. In cattle enrofloxacin?s major pharmacokinetic characteristics are a high bioavailability after parenteral administration, a large volume of distribution and relatively high concentrations in body tissues. Antibacterial activities in serum and tissues, achieved after subcutaneous administration of a dose of 2.5 mg/kg, are substantially above the MIC90 for most important pathogens of the bovine respiratory and intestinal tracts.