Developmental orthopedic diseases are a common cause of pain and lameness in young dogs. Most occur in large-breed dogs with rapid growth rates. This article reviews the signalment, etiology and pathogenesis, clinical signs, diagnosis, treatment, and prognosis for many of the common developmental orthopedic diseases, including hypertrophic osteodystrophy, panosteitis, osteochondrosis, Legg-Calve-Perthes disease, hip dysplasia, elbow dysplasia, and pes verus.