FRATURA SIMPLES COMPLETA DE OSSO SESAMOIDE DISTAL EM EQUINO: RELATO DE CASO

Abstract

Lesions in the hoof region are one of the most common causes of lameness in horses, mostly in the forelimbs. Navicular bone fractures, in turn, occur rarely, but it is known that their etiology may be congenital or secondary to trauma or other pathologies that lead to bone demineralization, usually causing acute lameness of moderate to severe. This report addresses a case of complete fracture of the distal sesamoid in an American Trotter mare attended by the team of the Gonzalez e Pereira Veterinary Hospital in Ribeirão Preto (São Paulo), in which the animal demonstrated a subtle lameness, probably due to the egg bar shoe that it used in the affected limb due to a history of injury at the origin of the billet-suspended ligament. A radiographic examination played an indispensable role in the conclusion of the diagnosis, revealing a radiotransparent vertical line in the parasagittal plane of the navicular bone with heterogeneous margins, suggestive of pathological fracture. However, it is practically impossible to differentiate a congenital condition and a chronic condition radiographically and even histologically. Healing is slow and occurs due to fibrosis, not bone union, which confers some instability and susceptibility to new lesions, so rest is a primary factor to ensure good healing. Treatment for these cases is generally conservative, since surgical resolution has a complicated and costly approach. Therefore, the diagnosis of distal sesamoid fracture is strenuous, but should be considered as a differential in cases of lameness, especially in forelimbs.