Equine castration: review of anatomy, approaches, techniques and complications in normal, cryptorchid and monorchid horses.

This research article provides an extensive review of the anatomy, techniques, and potential complications concerning horse castration, with a focus on normal, monorchid, and cryptorchid horses.

Understanding Embryological Development and Surgical Anatomy

• The study states the importance of understanding the embryological development and surgical anatomy of a horse to differentiate normal from abnormal structures. It helps to minimize possible complications during the castration process.

Castration Techniques

• Several techniques can be utilized for horse castration, including open, closed, and half-closed techniques.
• The castration of a normal horse can be operated under sedation and regional anesthesia while the animal is standing, or under general anesthesia when it is recumbent.
• Castration of cryptorchid horses is best executed under general anesthesia at a surgical facility.

Discussion on Cryptorchidism

• The article mentions that failure of left and right testicles to descend occurs almost with equal frequency. However, in cryptorchid horses, the left testicle is found in the abdomen in 75% of cases compared to 42% of right testicles.
• The study discusses various surgical approaches for castrating cryptorchid horses, including inguinal, parainguinal, suprapubic paramedian, or flank approach.
• Moreover, a new technique, laparoscopic castration, has been described but its application in practice is limited at this point.

Monorchid Horses

• Monorchidism, a condition where the horse only has one testis, can only be definitively diagnosed after a surgical examination of the abdomen, removal of the normal testis, and hormonal analyses.
• The hormonal assays that have been proven useful include the analysis of basal plasma or serum testosterone or oestrone sulphate concentrations, testosterone concentrations after hCG stimulation, and faecal oestrone sulphate concentrations.

Complications of Castration

• The article lists the potential postoperative complications of castration, including swelling, excessive haemorrhage, eventration, funiculitis, peritonitis, hydrocele, penile damage, and continued stallion-like behavior.