Incidence of Infective Endocarditis in Dogs After Balloon Dilatation of Congenital Pulmonic Stenosis Without Peri- and Postoperative Antimicrobial Prophylaxis

Balloon valvuloplasty is a commonly performed catheter-based procedure in dogs with congenital pulmonic stenosis. Worldwide, veterinary cardiologists often administer peri- and postoperative prophylactic antimicrobials to prevent infectious complications, like bacterial endocarditis. Infective endocarditis of the pulmonary valve is, however, extremely rare in dogs, and it has never been reported after balloon valvuloplasty. The objective of this retrospective case series was to investigate the incidence of infective endocarditis, if balloon dilatation of pulmonic stenosis was performed without antimicrobial prophylaxis. Medical records of dogs operated at a university teaching hospital in a 20-year period from 2006 to 2025 were reviewed for clinical signs and echocardiographic changes that could be caused by infective endocarditis. Of the 83 dogs that were operated without peri- or postoperative antimicrobial prophylaxis, survived the surgery, and had at least three weeks of follow-up, none developed infective endocarditis. Follow-up in 68 dogs was based on medical history, physical examination and echocardiography during rechecks at the authors’ institution. Follow-up information from the remaining 15 dogs was gained from the owners and/or the referring veterinarians. Our study demonstrated zero event rate in dogs that underwent balloon dilatation of congenital pulmonic stenosis without antimicrobial prophylaxis.