Equine Health Update EHU Vol 20 Issue 02 - Page 15

CPD Article | EQUINE Equine Castration and Complications Dr Arnold T Mahne BVSc(Hons), MMedVet(Chir)(Eq), Baker McVeigh Cape Town, Turf Club Road, Milnerton. Email: arnold@mcveigh.co.za Castration is one of the most commonly performed surgeries in the horse and is classified as open, semi- closed or closed. 10 This classification is not based on whether the skin is sutured or not. During an open castration, the parietal tunic (tunica vaginalis lamina parietalis) is opened and not removed. This is the method used most commonly when castrating a horse standing. The incisions are left open to heal with secondary intention. Closed and semi-closed castrations are best done under general anaesthesia. With a closed castration, the parietal tunic is not opened, and is removed with the testicle. A ligature can be placed around the spermatic cord. During a semi-closed castration, the parietal tunic is opened to allow separate clamping (and ligation) of the blood vessels, after which the parietal tunic is removed with the testicle. An additional ligature can also be placed around the spermatic cord. With closed or semi-closed castrations, the skin can be left open. The alternative, which allows for primary intention healing and less aftercare, is to suture the skin, provided that good aseptic technique was used and there was adequate haemostasis10. A new technique is the use of a Henderson tool, for castrating horses under general anaesthesia. After exteriorizing the testicle with the parietal tunic intact, the spermatic cord is clamped with the tool proximal to the testicle. The tool is attached to an electric hand drill, which is used to twist the testicle until it comes loose and is removed. 10 Complications Although castration is a relatively easy procedure, complications arising from castrations are common and often lead to malpractice claims against equine veterinarians. 2,4,12 Post-operative complications include haemorrhage, edema, infection, omental herniation, intestinal evisceration, septic peritonitis, penile damage, continued masculine behavior, vaginocoele, incomplete cryptorchid castration and death. 1,10 Haemorrhage In open castrations, some bleeding for 5 minutes post-emasculation should be regarded as normal. Haemorrhage is usually from the testicular artery and is caused by faulty instruments, applying the emasculator the wrong way around, not applying the emasculator perpendicular to the spermatic cord, not keeping it • Volume 20 Issue 2 | July 2018 • 15