Efficacy of ketamine hydrochloride administered as a basilar sesamoid nerve block in alleviating foot pain in horses caused by natural disease.

This research study aimed to evaluate the effectiveness of ketamine hydrochloride as a local anesthetic in horses suffering from foot pain. The results indicated that lidocaine was significantly more effective in improving the condition of the horses, with ketamine proving to be comparatively ineffective as a local anesthetic.

Objective and Methodology

• The primary objective of the research was to test whether a 3% solution of ketamine hydrochloride, administered perineurally around the palmar nerves at the base of the proximal sesamoid bones (a basilar sesamoid nerve block), could alleviate naturally occurring lameness in horses. This was compared to the application of lidocaine hydrochloride.
• The study was an experimental trial and involved seven horses who were chronically lame on a thoracic limb. The lameness was evaluated before and after the administration of both 2% lidocaine and 3% ketamine.
• This evaluation was done by using a wireless, inertial, sensor-based, motion analysis system to capture the animals’ movements. The assessments occurred at 5-minute intervals for 30 minutes after the local anesthetic was administered.
• The research also compared the change in gait produced after using lidocaine and the change produced after using ketamine. This was done through objective lameness assessment which used repeated measures analysis to compare the lameness scores obtained before and after the administration of both lidocaine and ketamine hydrochloride.

Research Findings

• The results revealed that the horses’ gait significantly improved after basilar sesamoid nerve blocks were performed using 2% lidocaine. However, the gait did not notably improve after the same nerve block was done using 3% ketamine hydrochloride. This indicates that ketamine was not as effective as lidocaine in improving the horses’ lameness.

Conclusion

• Consequentially, the research concluded that 3% ketamine, when administered perineurally for regional anesthesia of the digit, did not desensitize the digit to the same extent as lidocaine did. Thus, it was deduced that ketamine seems to be of no value as a local anesthetic agent for diagnostic regional anesthesia.