The use of local anesthetics reduces the intensity of pain stimuli during invasive procedures, thereby reducing postoperative pain intensity. The aim of the study was to determine the onset, duration and extent of regional blocks of the infraorbital nerve and its branches performed by injecting lidocaine and lidocaine-bupivacaine mixture into the infraorbital canal in dogs. Ten clinically healthy dogs, selected according to the principle of clinical analogues, were selected for the trial. Under general anesthesia, a pain stimulus was initiated by needle injection from the dorsolateral side into the gingiva of the maxillary canines, maxillary fourth premolars, and second molars. Changes in physiological indices were recorded on the patient's monitor.Heart rate and respiratory rate were measured. After baseline physiological indices were measured, 1 ml of 2% lidocaine solution was injected into the infraorbital canal (about two-thirds of the canal length) in one group and a mixture of 2% lidocaine and 0.5% bupivacaine (0.5 ml each) in the other group. Data were recorded for 4 hours.When infraorbital nerve blocks were performed in the first and second experimental groups of animals, anesthesia of the maxillary canine on the anesthetized side was achieved in 5 and 10 minutes, respectively. But nerve blocks of the fourth premolar and second molar were successful only in 2 dogs of the first group and 1 dog of the second group, respectively. The average duration of nerve block for the maxillary canine was 110 and 203 minutes after injection of lidocaine and lidocaine-bupivacaine mixture, respectively.Performing an infraorbital nerve block, as was done in this study, successfully blocks the innervation of the maxillary canine, but the results of nerve analgesia of the fourth premolar and second molar were inconsistent. This specific technique should not be used when extracting teeth caudal to the maxillary canine.