FLO a Golden Retriever, female, one and a half year old with a severe pulmonary stenosis withhypoplastic wide fibrotic subvalvular component. The pathology of Flo induced severe right heart failure with deterioration of health conditions. Despite the execution of a balloon valvuloplasty with low and high pressure device, the stenosis of Flo has not been reduced. The 30th April 2014 with the support of the Foundation Otto, Flo has undergone a ventriculotomy with patch- graft at the Clinica Veterinaria Malpensa , which allowed to increase the diameter of the pulmonary outflow tract drastically reducing the clinical signs and bringing Flo to a normal life again.