Congenital Heart Defect (Pulmonic Stenosis) in Dogs

The blood from the heart must flow in one direction, and the heart is equipped with valves to keep the blood from going backwards into any orifice, or opening. Pulmonic stenosis is an abnormality of the heart in which the semilunar valves do not work properly. These valves, the pulmonary valve and the aortic valve, each have a similar function. They both must seamlessly open and close to prevent any blood from back flowing into the corresponding orifices of the heart.

Pulmonic stenosis has several characteristics, such as the valve “leaflets” are too thick to properly work or even the leaflets becoming fused together, thus preventing them from opening and closing seamlessly.  This narrowing of the valve inhibits the function of the valve to properly open and close, and guide the blood in a one-way motion.

Pulmonic stenosis, or congenital heart defect in dogs, is caused by an abnormality in the valves of the heart. It can be specific to certain dog breeds.

If your dog has pulmonic stenosis, he may have no symptoms. If he has an advanced case of this heart defect his symptoms may include:

• Weakness
• Lethargy
• Intolerance to exercise
• Heart failure
• Collapsing
• Arrhythmia

Types

This congenital heart defect is found more so in specific dog breeds. Dog breeds that have a predisposition to pulmonic stenosis are:

• Bulldogs
• Jack Russel Terriers
• Boston Terriers
• Labrador Retrievers
• Newfoundlands
• Boxers
• Samoyeds

The cause of pulmonic stenosis is congenital and is breed specific.

If you suspect your dog is having heart problems, or if you have a specific breed that is showing symptoms from birth, make an appointment with your veterinarian. He will ask you about the history of the dog’s health and about his clinical signs before he does a complete examination. With the use of a stethoscope, the medical professional will be able to hear any heart murmur that is associated with this heart disease if the heart valves are not working properly. This may be the first sign that the heart has a defect.

The veterinarian will also perform several tests, such as angiocardiography or radiography. These imaging techniques take a closer look at the heart using injected dye to view the valves (angiocardiography) and also the shape and size of the heart (radiography).An echocardiogram is another test the veterinarian may perform to look closely at the valves and all of the structures that support the valves. It will also allow the veterinarian to see the blood flow throughout the heart. In addition to this, the doctor may also use an electrocardiogram to make a definitive diagnosis of pulmonic stenosis.

Depending on the severity of your dog’s condition, the veterinarian will outline a course of treatment for your companion. Treatment methods may include:

Aortic valvotomy

Also known as aortic valvuloplasty, this procedure is done to widen the opening where the aortic valve allows the blood to flow. A balloon, or balloon catheter, is put into place to give the valve greater flexibility (if it has thickened or stiffened) to help the valve perform more efficiently. This procedure is accomplished with general anesthesia.

Medications

Your veterinarian may prescribe specific medications to help with the function of the valves, such as beta blockers, or beta-adrenergic blocking agents to help with heart and valve functions. This may be done in conjunction with the balloon valvuloplasty.

If your dog has an advanced case of pulmonic stenosis, the veterinarian will give you options in caring for him at home. If your dog had a balloon valvuloplasty, the veterinarian will want to see him every few months to check his heart to be sure he is stable.  Any other treatment options will be assessed and the veterinarian will keep abreast on how he is responding to the treatment.

Any medications may need to be adjusted over time, and this is why it is vital to keep your veterinarian appointments consistent. With this congenital heart defect, your dog may live a healthy life with love and care by you, and with regular veterinarian visits. Every dog is different, and every case is unique, and in severe cases, the veterinarian will give you suggestions for his lifestyle and management.