Effect of palmar digital analgesia (as a result of "nerving") on forelimb loading over varied surfaces at the walk and trot - a pilot study

Abstract

Palmar digital neurectomy or “nerving” removes the sensation to the heel region of the hoof, while analgesia or “blocking” results in temporary loss of sensation. This pilot study examined the effect of loss of sensation in the forelimb heel (blocking). Three horses were fitted to hoof sensors on the front hooves. Horses completed the same randomized tests of walking and trotting on hard and soft ground pre and post-nerve blocking. Interaction of ground and blocking status was significant for area (P < 0.0001), with post-blocking having greater loaded area than pre while tracking on hard ground (P = 0.008). The same interaction was found significant for force (P <0.0001), with tracking over hard ground being greater post-blocking than pre (P = 0.008). Stride duration was longer pre-blocking than post (P = 0.0017). Findings from this pilot study show that temporary blocking impacts forelimb loading and that ground may be important in tracking for horses with removed sensation to the forelimb heel.