A large-scale epidemiological study was conducted to determine breeds at risk for 12 developmental orthopedic diseases (DODs). Developmental orthopedic diseases investigated included canine hip dysplasia (CHD); craniomandibular osteopathy (CMO); fragmented coronoid process; hypertrophic osteodystrophy; Legg-Calvé-Perthes disease; osteochondrosis of the medial humeral condyle, caudal humeral head, femoral condyles, and talar trochlear ridges; panosteitis; patella luxation; and ununited anconeal process. Dogs that were diagnosed with any one of the diseases of interest at any of 10 veterinary teaching hospitals participating in the Veterinary Medical Database from 1986 to 1995 were included as cases. Odds ratios and corresponding 95% confidence intervals were calculated to determine risk. Frequency of diagnosis during the 10-year period ranged from 35 cases (CMO) to 10,637 cases (CHD). The number of breeds at increased risk for a disease ranged from one (CMO) to 35 (CHD). Breed susceptibility for a DOD may suggest a genetic component in the disease etiology. The results of this study serve to increase veterinarians' awareness of breeds susceptible to DODs and may facilitate the control of such diseases by identifying breeds that might benefit from breeding programs or environmental intervention such as dietary modification.