This article describes the clinical presentation, diagnosis and management of osteochondrosis dissecans (OCD) of the caudal aspect of the humeral head in an eight-month-old Border Collie. OCD of the canine shoulder is a frequent cause of forelimb lameness in the dog. A typical presentation of lameness and pain on shoulder extension or flexion is seen in young medium- to giant-breed dogs, but it should be considered in almost all forelimb lameness work-ups. For most cases, management consists of excision of the cartilage flap and careful curettage or forage of the underlying subchondral bone to promote fibrocartilage. For all cases, a mild degenerative joint disease will ensue; however, with appropriate management, a good long-term prognosis can be expected in the majority of cases.