Epidural anesthesia is not prevalent in the dog but general anesthesia has been therefore attained through inhalation or various injection methods modified by each veterinarian's ingenuity. In the present experiment, we conducted epidural anesthesia in the dog to maintain and prolong the analgesia after the initial induction.
After the anesthesia with diazepam and ketamine hydrochloride, an injection needle was inserted into the epidural space via the lumbar vertebra to introduce a catheter. When 0.4 ml/kg of 2% lidocaine hydrochloride was injected through the catheter, the area from T11 to S2 segments was innervated and analgesic for 30 to 60 minutes. This condition was maintained for 110 to 150 minutes when 0.2 ml/kg of the anesthetic was added twice. The degree or extent of analgesia varied among the animals according to the location of the catheter end or the dog's posture: in some cases analgesia extended to T4 or C8 segment, while in others the lower side of the body remained analgesia for longer time. The cardiopulmonary functions were not affected in all cases.
