Keratoma of the hoof is a uncommon cause of persistent lameness in the horse. They should be suspected whenever a horse is suffering from a acute lameness of the foot and no other cause can be found, particularly (but not only) if there is a history of past trauma. Often the onset of the lameness is insidious and intermittent however with time can get quite severe. This article discusses diagnosis, treatment, and prognosis of keratoma of the equine hoof.

Keratoma is generally suspected when a horse has a persisted lameness that is referable to the hoof and radioraphs find a circular or semicircular area of radiolucency attributable to loss of bone of the third phalanx, ...more. Though the majority of these lesions involve the wall occasionally keratomas have been found on the sole.

Occasionally such areas can be found in sound horses so there is a bit of a diagnostic dilemma: is the lesion on the radiograph the cause of the lameness. If there is a history of a slow onset but progressively worsening lameness this should increase the degree of suspicion. If pain can be localized with the hoof testors over the area of the lesion this will greatly increase the degree of suspicion. Occasionally you may have to decide to treat without clear evidence this is the problem.

There also have been other tumors of the horses hoof that present as a keratoma would, including squamous cell carcinoma. When in doubt, histopath of the lesion at the time of surgery should be done to confirm the diagnosis.

Ultrasound has been useful for further delineating the lesion and very accurately characterizing its size and depth and is far more precise than radiography. Careful measurements can be very helpful during surgery.