FEASABILITY STUDY AND EVALUATION OF THE EFFICACY, SAFETY, AND SHORT AND LONG TERM FOLLOW UP OF A NEW TECHNIQUE FOR SURGICAL CASTRATION IN ADULT BOARS

INTRODUCTION Surgical castration of adult boars proves to be more challenging than that of piglets and despite it being less often necessary, it is still common practice. Classical techniques of orchiectomy require the use of ligatures and/or emasculator which can lead to an increased risk of surgical wound contamination and subsequent infection. For this aim, we devised a novel technique termed “sutureless castration” consisting of an open castration where the vas deferens is ruptured from the epididymis and tied into several square knots with the vascular portion of the spermatic cord. STUDY 1: A pilot study was conducted on 101 adult boars undergoing routine castration aiming to determine the feasibility and of the novel technique and power analysis was conducted to determine the sample size necessary for future studies. The boars were castrated by classical castration (G1; n=41) or sutureless castration (G2; n=60) and age (A), weight (W), and left and right deferent duct diameter and tensile strength (DDTS) were recorded. Pearson’s linear correlation coefficient was conducted on a homogeneous pool of 10 boars per group to determine the correlation between DDTS-A and DDTS-W. All the surgical procedures were successful, and no record of immediate postsurgical complications or mortality was noted. R value found for the pooled boars was 0.99 and 0.96 for DDTS-A and DDTS-W respectively. Power analysis showed that a significant level of accuracy determining the DDTS-A/W can be reached with a total sample of 388 deferent ducts. STUDY 2: A clinical follow up study was conducted on 403 boars castrated by the sutureless technique. Age, weight, deferent duct diameter and tensile strength were recorded, and DDTS-A and DDTS-W were analyzed by a Pearson correlation. A pool of 50 animals were randomly selected for inclusion in the short and long term follow up. For short term follow up, general and physical examination was conducted on days 1 to 4 and subsequently on day 7 and day 14. Data recorded included wound healing, gait stiffness, feeding behavior, other complications noted by the breeder and eventual death. Long-term follow up consisted of carcass inspection at slaughter and recording the presence of scar tissue, abscess, granuloma, and adherences at the surgical site and adjacent area. All surgeries were successful and correlation between DDTS-A and DDTS-W was strongly significant (R= 0.91 and 0.87). For short-term follow up, all animals showed some degree of swelling with 72% of them being only mild. The incidence of gait stiffness was 36% and that of myiasis 12%. A single case of abscess formation near the surgical site was recorded. Regarding long-term follow up, 26% of the animals had small subcutaneous scrotal granulomas which were considered to be unrelated to sutureless castration. CONCLUSION This novel technique of castration was validated for the use in adult boars and showed a success rate comparable to that of the classical technique. Additional studies should be conducted to determine its’ potential superiority in the matter of surgical time, cost efficiency and teachability.