A prospective multicentre survey of complications associated with equine castration to facilitate clinical audit

Despite the regularity with which castration is performed, the types of complications and current best practice are unknown.

The objective of this study was to perform a prospective audit of routine equine castrations performed in general practice to determine complication rates and factors associated with them.

Multicentre, prospective audit of castrations.

Data on castrations were collected on the day of surgery from 18 veterinary practices; 30-days post-operatively follow-up was obtained and complications recorded. Frequency of complications was reported, and multilevel, multivariable logistic regression models used to investigate factors associated with the most common complications of bleeding in the first 24 h, stiffness of gait and/or swelling and discharge and/or infection.

Data were collected on 495 castrations performed by 53 participating veterinary surgeons. Over two thirds of surgeries were performed outside, 21% were performed under standing sedation and 79% with the horse recumbent. Almost all (98 and 97%) patients received preoperative nonsteroidal anti-inflammatories (NSAIDs) and antimicrobials, respectively. One or more intraoperative complications were reported in 14.5% of procedures; most common were bleeding and excessive movement. Follow-up to 30 days was available for 392 equids. One or more complications were reported in 44 castrations (11.2%). Swelling was the most common, then infection and stiffness of gait. Serious complications were rare.

It is possible that there was bias towards submission of data for procedures where complications occurred. The low complication rates reduced the power to determine factors associated with complications. Minor complications may go unreported by owners and may be underrepresented.

Overall complications associated with castration are low and mortality rare. Findings from this study can be used as guidelines for practices to perform regular audit to determine if their negative outcomes are comparable or warrant further investigation.