Two dogs with a history of coughing and exercise intolerance were suspected to have a patent ductus arteriosus (PDA), and the presence of a type III PDA was confirmed by radiography, electrocardiography, ultrasonography and angiography. Transarterial coil embolisation was carried out by using a modified technique. An occlusion balloon catheter was inserted through a femoral vein and placed at the pulmonary side of the ductus before the embolisation coils were put in place. Both dogs remained healthy during a follow-up period of nine months.