Subvalvular aortic stenosis (canine)

Affects: Dogs

Overview

Canine subvalvular aortic stenosis (SAS) is an abnormal, congenital heart murmur caused by subaortic stenosis (SAS).

This genetic trait is polygenic, and in some cases asymptomatic. An animal with SAS may offspring and show no symptoms of the stenosis until multiple generations which is why it is advised not to breed an animal diagnosed with SAS.

Signs & Symptoms

Symptoms: Puppies and adult dogs diagnosed with subaortic stenosis can suffer from a range of clinical signs such as fainting, breathing difficulty in the moderate cases or heart failure and sudden death in severe cases. Symptoms also include sudden/strong lethargicism, continuous heavy panting, and a rise in temperature.

Diagnosis

Diagnosis: The Orthopedic Foundation for Animals (OFA) has established a Congenital Heart Registry whose guidelines were established by veterinary cardiologists. A dog which auscultates normally at 12 months of age is considered to be free of congenital heart disease. Upon confirmation of this, OFA will issue a certificate.

Educational information only. This page is general guidance and is not a substitute for professional veterinary advice. Never give medicines or change treatment without consulting a veterinarian. If your pet is unwell, contact OC Pets or seek emergency care.
Sources (reused under open licences, with thanks): Wikipedia — “Subvalvular aortic stenosis (canine)” (CC BY-SA 4.0) · Compiled by OC Pets Veterinary Clinic, updated 15-06-2026.