Selected Antimicrobial Information – Farm Animal

Enrofloxacin [Farm Animal]

Restriction Status

Unrestricted in non-food animals; ELDU prohibited in food animal species


Species Usage Dose
Camelids Label Dose 5mg/kg IM, or SQ q12-24h (extra-label use)
Cattle Label dose
  • 5-5mg/kg SQ q24h for 3-5d
  • 5-12.5mg/kg SQ once
Small Ruminants Label dose No labeled dose.
Swine Label dose 7.5 mg/kg SQ once in the post-auricular region; do not give more than 5mL per injection site

Brand Name(s)

Baytril® 100


Enrofloxacin is a concentration-dependent, bactericidal fluoroquinolone antibiotic with activity primarily against Gram-negative aerobes, such as Enterobacteriaceae and Pseudomonas aeruginosa. Gram-positive coverage is limited, though enrofloxacin is efficacious against many Staphylococcus spp. There is no coverage for anaerobic organisms. Distribution is wide, and excretion is primarily in the urine with also a lesser component of biliary excretion.

Current Uses within OSU-VMC

  • Treatment of bovine respiratory disease associated with Mycoplasma bovis, Pasteurella haemolytica, Pasteurella multocida, or Haemophilus somnus.
  • Treatment of swine respiratory disease associated with Mycoplasma hyopneumoniae, Bordetella bronchiseptica, Actinobacillus pleuropneumoniae, Pasteurella multocida, Haemophilus parasuis, or Streptococcus suis.
  • Treatment of swine colibacillosis (Escherichia coli enteritis) in weaned pigs.

Contraindicated Uses

  • Empiric treatment of Streptococcus spp. (efficacy is variable; culture and susceptibility testing recommended).
  • Anaerobic infections.

Illegal Uses

  • Extra-label drug use is prohibited in food animal species. Must only be used for therapeutic indication, species, dose, duration/frequency, and route of administration as stated on product label.
  • Not approved for use in lactating dairy cattle (>20 months of age) or calves to be processed for veal.

Formulations Available within the OSU Pharmacy

  • Enrofloxacin 100mg/ml injectable suspension
  • Enrofloxacin 20mg/ml oral suspension
  • Enrofloxacin 22.7mg tablet
  • Enrofloxacin 68mg tablet
  • Enrofloxacin 136mg tablet
  • Baytril 22.7mg/ml injectable suspension
  • Baytril 100mg/ml injectable suspension
  • Baytril 22.7mg tablet
  • Baytril 68mg tablet


  • None.


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OSU VMC Antimicrobial Use Guidelines Copyright © 2018 by The Ohio State University College of Veterinary Medicine is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.