Protected antimicrobial use in 19 equine veterinary practices in the United Kingdom

Summary Background Antimicrobials essential for human health must be used judiciously. Objectives Audit to quantify use and indications for ‘protected antibiotics’ in general equine practice. Study Design Prospective descriptive. Methods Systemic use of third‐generation cephalosporins (ceftiofur), fluoroquinolones (enrofloxacin and marbofloxacin), macrolides (clarithromycin), ansamycins (rifampin) and polymyxins (polymyxin B) (‘protected antibiotics’) was prospectively recorded in 19 practices over 6 months (April–September 2023). Univariable categorical comparisons were made using chi‐squared tests. Results Protected antibiotics were prescribed to 200 horses (10 horses prescribed two protected antibiotics concurrently). These 210 prescriptions included ceftiofur (48.2%), enrofloxacin (34.3%), marbofloxacin (7.1%), polymyxin B (6.2%), rifampin (2.8%) and clarithromycin (1.4%). Hospitals with an ambulatory practice generated protected antibiotic prescriptions in 0.53% of their ‘active patients’, compared to 0.17% in ambulatory only practices. The commonest indications were respiratory disease (18.0%), foal septic diseases (16.5%), gastrointestinal diseases (15.0%), complicated wounds (13.5%), ‘dummy’/premature foals (7.5%) and cellulitis/lymphangitis (6.5%). Of 190 horses prescribed protected antibiotics where age was recorded, 76 (40.0%) were foals. Horse age was associated with specific antibiotic use ( p < 0.001), with 73.7% of ceftiofur prescriptions for foals, and 97.0% and 100% of enrofloxacin and marbofloxacin prescriptions, respectively, for adults. Only 33.2% had antibiotic susceptibility testing (AST) performed; horses less than 1 year old were less likely to have AST compared to adults ( p < 0.001). Commonest justifications for protected antibiotic use were lack of alternative preparations suitable for foals (27.5%), AST results (24.9%) and failure to respond to previous antibiotic treatment (17.1%). Dose rates were variable but generally appropriate. Main Limitations Convenience sampling. Small number of cases. Aminoglycoside use not evaluated. Conclusions Foal infections, respiratory and gastrointestinal diseases and complicated wounds were the commonest reasons for protected antibiotic use. Lack of alternative drugs (for foals) and AST results or failed previous treatments were the commonest justifications.