Legg-Calve-Perthes disease (LCPD) is a juvenile-onset hip-joint disease that occurs in an estimated 2% of small breed dogs. It is characterized by cell death to the femoral head, the part of the hip joint that acts as the ball in the ball-and-socket joint of the hip. Common symptoms include lameness, hip pain, inability to bear weight on the joint, shrinkage of leg muscles, and decreased joint function. Diagnosis is by radiograph upon clinical observation of lameness. However, the lameness does not manifest until the disease progresses, and the earlier the diagnosis, the better the recovery following treatment. The most common treatment is surgery, which is often expensive and invasive with long recovery times. Genetic testing does not yet exist for the disease in dogs. Therefore, we propose to genetically map LCPD in dogs using 86 cases and 86 controls by using a genome-wide association study (GWAS), a genetic technique that compares the DNA between groups of individuals that have a trait or disease to those who do not in order to find common genetic variants associated with the trait. Following this, whole-genome sequencing of 10 of these cases and 10 of these controls will be conducted for increased mapping power and additional variant discovery. We expect to find at least one mutation on chromosome 6 between 29.7-34.3 Mb that is associated with the development of LCPD in small breed dogs based on our preliminary results. If we can find the mutations causative for LCPD in dogs, a genetic test can be designed.