Ventricular Septal Defect

Ventricular Septal Defect (VSD)

Ventricular Septal Defect (VSD) is a congenital heart defect in dogs characterized by a hole in the wall (septum) that separates the two lower chambers of the heart — the right and left ventricles. This opening allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle. Depending on the size and location of the defect, this can lead to abnormal blood flow, increased workload on the heart, and potential heart failure over time. VSDs are among the most common congenital heart defects seen in dogs.

Dogs with a Ventricular Septal Defect may show symptoms related to heart strain or poor circulation, including rapid breathing, coughing, fatigue, exercise intolerance, fainting, and slow growth in puppies. In severe cases, dogs may develop congestive heart failure, characterized by difficulty breathing and fluid buildup in the lungs or abdomen. Some dogs with small VSDs may show no outward symptoms and are diagnosed incidentally during a routine veterinary examination when a heart murmur is detected.

The cause of VSD is genetic and developmental, occurring when the fetal heart fails to form a complete septal wall during gestation. It is considered a congenital (present at birth) condition and cannot be acquired later in life. The severity of the defect depends on the size of the opening and how much blood passes through it. Small defects may close naturally as the dog matures, while larger defects often require medical or surgical intervention.

Dog Breeds Commonly Affected by Ventricular Septal Defect (VSD)

Although VSD can occur in any breed, it is more frequently reported in certain purebred dogs, including:

• English Bulldogs
• Keeshonds
• Beagles
• Samoyeds
• Boston Terriers
• Springer Spaniels
• Labrador Retrievers
• Siberian Huskies
• Airedale Terriers
• West Highland White Terriers

Diagnosis of VSD typically involves a thorough cardiac evaluation, including chest X-rays, echocardiography (heart ultrasound), electrocardiogram (ECG), and cardiac catheterization to determine the size and impact of the defect. Small VSDs may not require treatment but should be monitored regularly. For moderate to severe cases, medications such as diuretics, ACE inhibitors, or beta-blockers may be prescribed to manage symptoms and reduce heart strain. In certain cases, surgical closure or catheter-based repair can be performed by a veterinary cardiologist to correct the defect.

The prognosis for dogs with VSD varies depending on the size of the defect and the degree of heart involvement. Dogs with small defects often live normal, healthy lives, while those with larger or uncorrected defects may develop complications such as heart enlargement or failure. Early detection through routine veterinary exams and regular monitoring by a cardiologist are essential. With proper care, medication, and monitoring, many dogs with VSD can maintain a good quality of life for years.