Osseous metaplasia in the deep digital flexor muscle of a Neapolitan Mastiff/Metaplasia ósea en el músculo flexor digital profundo en un Mastín Napolitano/Metaplasia óssea no músculo flexor digital profundo num Mastim Napolitano

The authors have described a case of osseous metaplasia in a canine. A female Neapolitan Mastiff with a history of intermittent left forelimb lameness was evaluated. Orthopedic examination revealed the animal was not standing on the affected limb and had signs of pain on passive flexion and extension of the left elbow joint. A solid mass medial of the left elbow was detected on palpation. Radiological examination showed a radiopaque structure medial to the joint, at the level of flexor muscles of the left forelimb, without evident adhesion or contact with bone. The mass was surgically removed and histologically examined. The mass was diagnosed as an altered metaplasic regeneration with formation of bone tissue. The patient showed marked improvement of the lameness few days after surgery and at reevaluation 12 months post-surgery. This report describes a case of osseous metaplasia at the level of the forelimb flexor muscles in a canine patient.