Effects of anesthesia of the palmar digital nerves on kinematic gait analysis in horses with and without navicular disease.

OBJECTIVE

To determine the effect of local anesthesia of the palmar digital nerves on forelimb kinematics in Quarter Horses with and without navicular disease.

ANIMALS

12 adult Quarter Horses; 5 clinically normal (sound) and 7 with navicular disease.

PROCEDURE

Kinematic measurements were made on adult horses trotting on a treadmill, before and after palmar digital nerve block (PDNB). Twenty-three displacement, joint angle, and temporal gait measurements of the right forelimb and head were made for 5 strides in each horse. Initial (before local anesthesia) right forelimb measurements were obtained after a left forelimb PDNB. Kinematic measurements were compared before and after PDNB of the right forelimb by multiple ANOVA with an alpha = 0.05, adjusted for posthoc comparisons by Bonferroni correction.

RESULTS

In sound horses, the only significant change in kinematic measurements after PDNB nerve block was in the maximum extension of the metacarpophalangeal joint at mid-stance, which was decreased by an angle of 2 degrees. In horses with navicular disease, mean maximum extension of the metacarpophalangeal joint during stance phase and maximum flexion of the carpal joint during swing phase were significantly increased after PDNB. Also, total stance phase, cranial stance phase, and break-over durations were significantly shorter. In horses with navicular disease, differences between minimum head heights during stance phase of each forelimb and total vertical head excursion during a complete stride were significantly smaller after PDNB.

CONCLUSION

Several kinematic measurements of gait can be used to determine improvement of lameness in horses with navicular disease after PDNB block while trotting on a treadmill.