Pudendal and caudal rectal nerve blocks in the horse – An anesthetic procedure for reproductive surgery.

The study investigates the effectiveness of a local anesthetic procedure for reproductive surgery in horses, specifically targeting the pudendal and caudal rectal nerves. The procedure was found to effectively numb the desired areas in both male and female horses.

Objective of the Study

• The primary aim was to explore the feasibility of anesthetizing the pudendal and caudal rectal nerves in horses to facilitate reproductive surgeries. This involved injecting a local anesthetic solution into a specific location and observing the extent of anesthesia.
• The researchers also sought to establish the precise placement for the anesthetic solution for maximum efficacy,

Methodology

• The experiment involved nine crossbred adult horses (four male and five female).
• An anesthetic solution was injected at a specific location, the foramen for the caudal gluteal artery and vein in the sacrosciatic ligament. This was done using a 15-cm, 18-gauge needle, and a volume of 20 milliliters of solution was used.
• To determine the extent of anesthesia, quantitative data were collected post-injection.
• In four additional horses, dye was injected alongside the anesthetic solution for postmortem examination to verify the accurate placement of the solution.

Findings

• The research revealed that by placing the anesthetic near the foramen for the caudal gluteal vessels in the sacrosciatic ligament, it was possible to achieve satisfactory anesthesia of specific reproductive regions in both male and female horses.
• In mares, the effective areas were the anus, perineum, and vulva, while in the male horses, the anesthetized areas were the anus, perineum, glans penis, and the penile layer of the prepuce.
• The study also noted the occurrence of penile extrusion in the case of the male horses. This finding suggests that this anesthetic procedure might have implications beyond just numbing the area, indicating a potential effect on erectile function.

Conclusion

• The study demonstrates the viability of this anesthetic procedure for equine reproductive surgery. By accurately placing the solution, it’s possible to achieve significant anesthesia of the necessary areas to carry out the procedure.
• The researchers also hint at further investigations into the observed penile extrusion, offering room for more nuanced understanding of this anesthetic procedure’s effects.