Evaluation of Autoligation of the Spermatic Cord for Castration of Small Adult Dogs

Abstract

Introduction: Traditionally, when performing a canine castration, the spermatic cord is double ligated prior to removing the testicles. Double ligation with suture is thought to prevent hemorrhagic complications and has been considered necessary to prevent morbidity and mortality when performing these procedures. A relatively new technique has emerged where the spermatic cord is ligated on itself, or autoligated, in a manner similar to the way that feline spermatic cords are ligated when performing cat neuters. The purpose of this study was to evaluate the rate of complications across a large number of dogs whose spermatic cords were autoligated rather than double ligated with suture. At the time of the study there was no peer-reviewed publication of this scale providing information about post-operative complications that could result from using this specific technique.

Methods: This case series included 215 shelter-owned dogs that underwent autoligation of the spermatic cord during routine open castration. Inclusion criteria included age of 5 months or older and body weight of 25 lbs (11.4 kg) or less. Age was obtained from records, when available, or estimated based on size, breed, and dentition. The primary outcome measure was defined as hemorrhage from the testicular pedicle, as the primary potential complication that would be expected from a novel or unproven ligation method. Thus, patients were monitored for intraoperative hemorrhage, postoperative bleeding, or development of a scrotal hematoma. Incisional bruising was also found but not attributed to bleeding from the testicular pedicle unless noticed to be overtly greater than what is observed with traditional canine castration surgery.

Results: There were no intraoperative hemorrhage-related complications in any dog. In addition, none of the patients experienced postoperative bleeding nor did any patient develop a scrotal hematoma. Minor complications were all mild and self-limiting. These included peri-incisional bruising in 10/215 (4.7%) and scrotal bruising in 8/215 (3.7%) for an overall complication rate of 18/215 (8.4%). No dog required hospitalization or medical care related to any surgical complication.

Conclusion: No severe complications were seen in this case series of 215 patients. Calculating the upper limit of the 95% exact binomial confidence interval suggests a maximum risk of 1.7% that severe complications would be encountered in performing this procedure. Therefore, the results of this study indicate that autoligation of the spermatic cord is a safe technique when used in the open castration of adult dogs that weigh 25 pounds (11.4 kg) or less. Anecdotally, many shelter veterinarians report using this technique and this publication serves to establish the safety of this practice, particularly for those practicing in high-quality/high-volume spay and neuter operations.