Descrição clinico-histológico do queratoma em equino

Abstract

Keratoma is an uncommon equine hoof disorder characterized by the growth of a keratinous mass between the hoof wall and the distal phalanx, causing compression of the sensitive structures of the digit. This condition results in chronic lameness, recurrent abscesses, and in some cases, visible deformities of the hoof wall and white line, often being mistaken for other hoof diseases. The present study reports the findings of a case of keratoma in a horse, highlighting the clinical and histological aspects of this condition. A 15-year-old Campolina gelding was presented at the Veterinary Teaching Hospital of the Federal University of Paraíba with a history of recurrent subsolar abscesses in the left forelimb and chronic lameness. Physical examination revealed hoof wall deformity, purulent discharge, and sensitivity to hoof testers. Radiographic examination showed a semicircular radiolucency in the distal phalanx, suggestive of keratoma, which was later confirmed by histopathological analysis of the excised mass. Treatment consisted of hoof wall resection from the coronary band to the toe for lesion removal, associated with stabilization using an inverted horseshoe and cast. However, recurrence occurred within a week, confirmed by a new biopsy. A second, more invasive surgery under general anesthesia was performed, and although the horse initially recovered well, another recurrence was observed three weeks later, confirmed histologically. The animal currently remains affected and awaits a new surgical approach. Although the prognosis for keratomas is generally favorable, it becomes guarded in recurrent cases, usually due to incomplete removal of the tumor. Therefore, despite being rare, keratoma should be considered in cases of recurrent abscesses and lameness. This case highlights the clinical presentation, diagnostic process from physical examination to histopathology, and emphasizes the importance of early diagnosis, complementary imaging, and complete lesion removal to prevent recurrence and ensure the horse’s return to activity.