Tiletamine-Zolazepam, Ketamine, and Xylazine Anesthetic Protocol for High-Quality, High-Volume Spay and Neuter of Free-Roaming Cats in Seoul, Korea.

This study was performed to evaluate the anesthetic protocol used in the high-quality, high-volume spay and neuter (HQHVSN) of free-roaming cats in Seoul, Korea from 2017 to 2022. The evaluation was performed on a total of 1261 free-roaming cats, with an average weight of 3.48 ± 1.04 kg. The anesthetic combination tiletamine-zolazepam, ketamine, and xylazine (ZKX) was injected intramuscularly. The actual drug doses administered were tiletamine-zolazepam 5.52 ± 1.70 mg/kg, ketamine 8.94 ± 3.60 mg/kg, and xylazine 1.11 ± 0.34 mg/kg. Additional doses were required in 275 cats out of a total of 1261 (21.8%). Following anesthesia and surgery, 1257 cats (99.7%) were returned to their original locations. Four cats (0.3%) died postoperatively. The mean duration of anesthesia (from ZKX combination to yohimbine administration) was 26 ± 22 min for males and 55 ± 36 min for females, while the time from yohimbine administration to the recovery was 31 ± 22 min for males and 20 ± 17 min for females. The use of ZKX for HQHVSN of free-roaming cats is inexpensive, provides predictable results, can be administered quickly and easily in a small volume, and is associated with a low mortality rate during the first 72 h post-surgery.