We report radiographic changes and clinical results seen in the proximal femur and coxofemoral joint of 7 young dogs following intramedullary pinning. Changes seen radiographically included coxa valga, a small malformed femoral head, a short thin femoral neck, and coxofemoral subluxation. Epiphyseal trauma, ischemia, and mechanical impairment of normal femoral neck growth due to presence of the intramedullary pin are discussed as possible etiologic factors.