Open standing castration in Thoroughbred racehorses in Hong Kong: Prevalence and severity of complications 30 days post-castration.

This study focuses on the complications encountered during open standing castration of Thoroughbred racehorses in Hong Kong. The research explores the prevalence and severity of these complications 30 days post-castration and suggests a need for reviewing the castration technique due to the high frequency of complications and antibiotic usage observed.

Research Methodology

• The study conducted a retrospective review of veterinary clinical records of horses which underwent open standing castration (OSC) between July 2007 and July 2012.
• A severity score, ranging from N for no complications to C3 for severe complications, was used to assess the complications.
• Other data acquired for each horse included age, import date, racing history, trainer and the veterinarian in charge of the castration.
• Bacterial cultures and antimicrobial sensitivities were tested on a few castration wounds which later developed infections.

Research Findings

• The study involves 250 horses that were castrated using the OSC technique during the study period.
• It was observed that 60% of these horses (150 out of 250) experienced some kind of post-castration complications including scrotal swelling, funiculitis, and seroma formation, which were found in 70.0%, 36.7%, and 24.7% of the cases respectively.
• A small number of horses (8 out of 250) experienced severe complications requiring intensive veterinary treatment.
• The majority of horses showing complications required additional procedures such as the reopening of the wound or an extended course of first-line antimicrobials or nonsteroidal anti-inflammatory drugs (NSAIDs).
• Bacterial cultures were conducted for eight horses revealing 17 bacterial isolates. The bacteria were found to be sensitive to enrofloxacin and ceftiofur but showed resistance to drugs like penicillin, gentamicin, oxytetracycline, metronidazole, and trimethoprim-sulfadiazine.

Conclusion

• The study concludes that complications after open standing castration in racehorses in Hong Kong were quite common. However, most of the complications were mild and could be effectively treated using antimicrobials and basic wound management.
• Given the extent of complications and antimicrobial usage observed in this study, the researchers recommend a review of the castration technique.
• The study could not, however, account for discrepancies in post-castration management which might have influenced the results.