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Subaortic Stenosis in Dogs: Cardiac Welfare

Subaortic stenosis is a congenital heart defect causing obstruction to blood flow. This guide covers welfare implications and management.

Key Facts

SAS involves fibrous tissue narrowing the outflow tract below the aortic valve
Large breeds (Newfoundlands, Golden Retrievers, Boxers) are predisposed
Severity ranges from mild (no symptoms) to severe (exercise intolerance, sudden death)
A systolic murmur at the left heart base is characteristic
Severe SAS can cause syncope and sudden cardiac death in young dogs
Breeding affected dogs perpetuates the condition in predisposed breeds

Welfare Considerations and Management

Welfare management depends on severity. Mildly affected dogs may need no treatment but require monitoring. Moderate to severe cases benefit from atenolol (beta-blocker) to reduce heart rate and myocardial oxygen demand. Balloon dilation and surgical intervention have limited success. Affected dogs should avoid strenuous exercise. Responsible breeding using echocardiographic screening reduces the prevalence in predisposed breeds.

What You Can Do

Seek specialist cardiology assessment for any dog with a heart murmur
Restrict exercise appropriately based on severity of obstruction
Screen breeding dogs from predisposed breeds with echocardiography
Do not breed dogs with moderate or severe SAS