Critically important antimicrobials are frequently used on equine racetracks

Area of Science:

• Veterinary Pharmacology
• Equine Health
• Antimicrobial Stewardship

Background:

• Antimicrobial use in equine populations, particularly at racetracks, requires characterization to ensure responsible stewardship.
• Understanding prescribing patterns is crucial for identifying potential areas of overuse or misuse.

Purpose of the Study:

• To characterize the patterns of antimicrobial drug use in horses stabled at four racetracks in the eastern United States during the 2017-2018 racing seasons.
• To identify the most frequently prescribed antimicrobials and their indications.

Main Methods:

• Daily treatment sheets from attending veterinarians at four racetracks were collected.
• Handwritten data on treatments administered to horses were manually transcribed and analyzed.

Main Results:

• A total of 2,684 antimicrobial prescriptions were recorded, comprising 6.8% of all drug treatments.
• Enrofloxacin was the most frequent antimicrobial (31.8%), followed by gentamicin (21.2%), ceftiofur (14.5%), and penicillin (8.2%).
• Frequencies of antimicrobial classes and indications varied significantly between racetracks and veterinarians.

Conclusions:

• Antimicrobials were prescribed infrequently compared to other drugs at racetracks.
• Highly or critically important antimicrobials were predominantly used, raising concerns about stewardship.
• The appropriateness of antimicrobial use in this setting remains unknown and warrants further investigation.