LAPAROSCOPIC CRYPTORCHID CASTRATION IN STANDING HORSES

Objective-This article describes a new technique for laparoscopic cryp torchid castration in standing horses. Study Design-Prospective study. Animals or Sample Population-Eight horses aged 11 months to 3 years a nd weighing between 300 and 643 kg. Methods-Food was withheld for 24 t o 36 hours, and then horses were sedated with detomidine HCl (0.02 to 0.03 mg/kg) and butorphanol tartrate (0.02 mg/kg). The paralumbar foss a region was desensitized with 2% mepivacaine in an inverted ''L'' pat tern and caudal epidural anesthesia was administered with either xylaz ine (0.18 mg/kg diluted to 10 to 15 mL with 0.9% sodium chloride) or a combination of 2% mepivacaine and xylazine (0.18 mg/kg). Initial lapa roscopic exploration was performed from the left flank; in three horse s, right flank laparoscopy was needed to complete the procedure. The s permatic cord was ligated within the abdomen with one or two sutures o f 0 polydioxanone suture, and the testis or testes removed through a f lank incision. Results-In five horses with no palpably descended teste s, standing laparoscopy was the only procedure performed, whereas in t wo horses, the abdominal testis was removed laparoscopically, and the descended testis was removed under short acting anesthesia. In one hor se, with nonpalpable testes, it was determined by laparoscopic observa tion that the testes were in the inguinal canal, and castration was pe rformed under general anesthesia. No surgical or postoperative complic ations were noted. The right side of the abdomen, and especially the r ight vaginal ring, could be easily observed from the left side by pass ing the laparoscope through a small perforation in the mesocolon of th e descending colon or by elevating the descending colon with an instru ment or by use of an arm in the rectum. Conclusions-The standing lapar oscopic approach combined with or without short-acting anesthesia to r emove the descended testis is easily performed. Clinical Relevance-Thi s approach will provide surgeons with another option to castrate crypt orchid stallions. (C) Copyright 1997 by The American College of Veteri nary Surgeons.