Effect of erythromycin and colistin ophthalmic ointment on post‐race keratitis in Thoroughbred racehorses
Hiroki Ueshiba, Taisuke Kuroda, Hidekazu Niwa, Mai Iimori, Minoru Ohta, Shinjiro KurimotoAbstract
Background
This study investigated the prophylactic efficacy of administering an ophthalmic ointment containing erythromycin and colistin (EC ointment) after racing to prevent post‐race keratitis in Thoroughbred racehorses.
Methods
The incidence of post‐race keratitis following turf and dirt races was compared between treatment groups (non‐ointment group: eye flushing only; ointment group: eye flushing and application of EC ointment) and between two randomly assigned groups (non‐antimicrobial group: application of ophthalmic white petrolatum; antimicrobial group: application of EC ointment).
Results
After turf races, the incidence of post‐race keratitis was significantly higher in the non‐ointment group (6.25%; 63/1008) than in the ointment group (0.55%; 53/9659) and in the non‐antimicrobial group (8.18%; 13/159) than in the antimicrobial group (0%; 0/152). In contrast, after dirt races, no significant differences were found between the non‐ointment (0.56%; 8/1420) and ointment (0.53%; 53/9986) groups, or between the non‐antimicrobial (1.87%; 4/214) and antimicrobial (1.41%; 3/213) groups.
Limitations
Microbiological and cytological testing was limited, and the pathogenesis of post‐race keratitis remains unclear.
Conclusions
EC ointment effectively reduced the incidence of post‐race keratitis after turf races, but not after dirt races. Although the findings suggest bacterial involvement in the pathogenesis of post‐turf‐race keratitis, further microbiological and cytological testing is warranted to confirm this.