Negative palmar angle syndrome in racing horses

Negative palmar angle syndrome in racing horses

Early recognition and correcton can prevent this potentially career-ending pathology
Dec 01, 2010


Photo 7: Grade IV forms of NPAS are complicated by flexor contracture, causing a "post-legged" appearance in which the pastern is more vertical than normal and the fetlock angle is reduced.
In my experience, success depends on obtaining good lateral radiographs, gauging the severity of NPAS and applying an appropriate trimming and shoeing strategy according to the severity of the disorder and the needs of the individual horse.

If this condition is not treated appropriately, severe contracture of the heels can develop, followed by quarter cracks or heel fractures, either of which makes the management of NPAS more complicated and delays the return to soundness. Suppurating corns may also develop and can lead to proximal migration of the infection into the collateral cartilages and even the distal interphalangeal joint.


NPAS is a treatable condition. Unfortunately, many affected horses that are not treated properly are retired, some after having undergone neurectomies because nothing else has made them comfortable. But with a little know-how and some patience, you can treat these cases and be rewarded for your efforts with a satisfied client and a happy horse.

Andrea E. Floyd, DVM, has specialized in equine podiatry for more than 25 years. She is the owner of Serenity Equine, Evington, Va., and the author of Equine Podiatry. Dr. Floyd is a member of the American Veterinary Medical Association, American Association of Equine Practitioners and the American Farriers Association.


1. Floyd AE. Use of a grading system to facilitate treatment and prognosis in horses with negative palmar angle syndrome (heel collapse): 107 cases. J Equine Vet Sci 2010;30(11):[in press].