Evaluation of ‘Section-Ligation-Release (SLR)’ technique devised for castration in the stallion.

The study examines the use of a new castration method, called ‘Section-Ligation-Release (SLR)’, in stallions and its possible benefits over traditional techniques. The results showed that the SLR method successfully lowered testosterone levels, indicating successful castration, and had minimal complications, suggesting it could be a valid alternative method.

Methodology of the Study

• The researchers tested the SLR castration technique on five stallions, aged between 24 and 48 months. The procedure was performed under general anaesthesia.
• Two 5 cm incisions were made at the scrotal neck of each stallion, and sharp dissection was performed through the protective layer surrounding the testes – the parietal vaginal tunic.
• Both the blood vessels and non-vascular structures in the cords were triple clamped, cut and tied off. However, the testes were left in their original position instead of being removed as in traditional castration.
• Before and two months after the operation, the researchers collected serum to measure testosterone levels. After the castration, horses were intravenously given human chorionic gonadotrophin (hCG), a hormone that normally causes an increase in testosterone, to assess the response.
• The testes were collected after two months for microscopic examination.

Project Findings

• The SLR castration was performed successfully on all five stallions.
• The main short-term complication recorded was moderate swelling of the scrotum and prepuce (skin surrounding the tip of the penis).
• Measurement of testosterone levels two months after the operation found significant reduction, indicating successful castration. Moreover, the testosterone level did not increase after the administration of hCG which further confirms the success of castration as there is no active testicular tissue left to respond to the hormone.
• Microscopic examination of the testes revealed hyalinization (a process where tissue becomes glassy and smooth) of the seminiferous tubules (the tubes where sperm are produced) and loss of testicular interstitial tissue between the tubules, suggesting complete destruction of the tissue due to lack of blood supply (avascular necrosis). This was another positive indicator of successful castration.
• The authors suggest that the SLR technique is a simple, practical method with minimal post-operative complications. They propose that it could be considered as an alternative to traditional castration which usually lets scrotal wounds heal by second intention (healing of a wound by granulation tissue filling in from the base).