Caval syndrome due to infection with Dirofilaria (D.) immitis is a life-threatening situation, needing immediate therapeutic intervention. Severe pulmonary hypertension due to dirofilariosis was diagnosed echocardiographically in a 3.6 kg dog with heart failure and moderate hemolytic anemia. A ball of adult worms was visualized in the tricuspid valve area. Using a modified pigtail catheter, these worms were removed under fluoroscopic guidance by a transvenous approach. Already intraoperatively the hemodynamic condition improved. Subsequently, additional routine adulticide treatment was performed without complications. Over the following weeks the severe pulmonary hypertension normalized slowly but steadily. Manual extraction of adult D. immitis can be achieved with relatively simple tools and allows rapid stabilization of a critically sick patient.