Evaluation of Low-Level Laser Effects on Epidural Anesthesia in Horse

Abstract Objective: To evaluate and compare the analgesic effects of caudal epidural administration of lidocaine (LIDO), caudal laser radiation and epidural lidocaine plus laser radiation in horses. Study design: A blinded, randomized, prospective, experimental cross-over study. Animals: Five healthy horses, 15.7 +/- 4.9 years of age, weighing 240 +/- 37 kg. Methods: The horses were randomly assigned to receive four treatments (group NS: saline (0.9% NaCl) solution via caudal epidural injection,group L: lidocaine( 2 mg/kg of body weight) via caudal epidural injection, group LLL: laser radiation (3000hrtz- for 10 minute) and group LL: caudal epidural lidocaine injection plus laser radiation at intervals of at least 1 week. Motor and sensory blockade evaluations used by TENS machine. perineal analgesia Anal and vaginal tone was recorded. Positive pain responses were defined as purposeful avoidance movements of the head, neck, trunk, limbs and tail. Absence of attempts to kick, bite and turning of the head toward the stimulation site were used to indicate analgesia. Results:.Analgesia produced in the tail, perineum and upper hind limb in all horses received lidocaine. Statistical analyses assessed sensory and motor stimulation and did not show a significant difference between horses in groups 1, 2, 3, 4 in right and left sides. Conclusion and clinical Relevance: We concluded that low level laser in combination with caudal epidural lidocaine treatments provided sufficient analgesia in horses, and this treatment is offered a longer duration of analgesia than laser, lidocaine caudal administration although the sensory and motor stimulation did not show significant difference between groups. Low level laser may be effective adjuvants in caudal epidural anesthesia in horses. Our results showed that LLL plus lidocaine may be preferable to a high dose of epidural lidocaine.