2-year-old, intact female, a Golden Retriever Dog was presented with the signs of respiratory distress, exercise intolerance, and muscular weakness. A high-grade systolic murmur was auscultated over the tricuspid valvular area. Thoracic radiographs showed an enlarged D-shape heart and free fluid (chylothorax) in the pleural space. ECG revealed small QRS complexes. Doppler echocardiography disclosed severe tricuspid insufficiency with moderate pulmonary hypertension, and tricuspid leaflets also were displaced down into the right ventricle, substantiating Ebstein's anomaly. Five-weeks after the medical therapy, patient died at home. The owner of the patient refused the necropsy. This is the first case report of tricuspid dysplasia and Ebstein's anomaly along with chylothorax in dogs.