Narrowing of the heart blood vessels in pets - Pulmonic stenosis and aortic stenosis

Congenital narrowing of the heart vessels is an important cause of heart problems in dogs and cats. The most common forms are pulmonic stenosis (narrowing of the pulmonary artery) and aortic stenosis (narrowing of the main body artery). These conditions cause increased pressure within the heart and can lead to heart failure or sudden death.

In this article we discuss the causes, symptoms, diagnosis, and treatment options for pulmonic stenosis and aortic stenosis in pets.

What are narrowings of the heart vessels?

With a stenosis, a blood vessel is narrowed, forcing the heart to pump harder to move blood through it. This leads to thickening of the heart muscle and, ultimately, heart failure. Pulmonic stenosis involves the pulmonary artery; aortic stenosis involves the main body artery (aorta).

Pulmonic stenosis

Pulmonic stenosis is a narrowing of the pulmonary artery or the heart valve leading into it. This is common in certain dog breeds such as the English Bulldog, Boxer, and Chihuahua. The narrowing causes increased pressure in the right ventricle, which can lead to thickening of the heart muscle and heart rhythm disturbances.

Aortic stenosis

Aortic stenosis is a narrowing of the outflow from the left ventricle into the aorta. This is common in large dog breeds such as the German Shepherd, Golden Retriever, and Newfoundland. The left ventricle has to work harder, causing the heart muscle to thicken and eventually pump less efficiently.

Symptoms of stenoses

• Reduced stamina
• Fainting or collapse, especially during exertion
• Irregular heartbeat or rhythm disturbances
• Difficulty breathing or coughing
• In severe cases: sudden death

Diagnosis of stenoses

Pulmonic stenosis or aortic stenosis is diagnosed using:

• Physical examination and auscultation: often a loud heart murmur
• Echocardiography: the gold standard for measuring the narrowing and pressure
• X-rays: show heart enlargement or changes in the lungs
• ECG: to detect heart rhythm disturbances
• CT scan: in some cases, for a more precise assessment

Treatment of pulmonic stenosis

The most common treatment is balloon dilation, in which a catheter and balloon are used to widen the narrowing. In severe cases, surgery may be necessary. Medication such as beta-blockers can help reduce the strain on the heart.

Treatment of aortic stenosis

Treatment of aortic stenosis is more complex. Medications such as beta-blockers and ACE inhibitors can reduce the strain, but a full cure is often not possible. Surgery or catheter-based interventions are performed at a few specialized centers, but results vary.

Prognosis

The prognosis depends on the severity of the stenosis. In mild cases, animals can often lead a normal life with regular monitoring. Severe stenoses carry an increased risk of sudden death and require intensive treatment and follow-up.

Want to know more?

Read more about cardiology and congenital heart defects at Nesto. Our specialized veterinarians have experience diagnosing and treating pulmonic stenosis and aortic stenosis in dogs and cats.

Frequently asked questions (FAQ)

What is the difference between pulmonic stenosis and aortic stenosis?

Pulmonic stenosis is a narrowing of the pulmonary artery, while aortic stenosis is a narrowing of the main body artery.

Which breeds are more prone to stenoses?

Pulmonic stenosis is more common in the French and English Bulldog, terrier breeds, Miniature Schnauzer, Labrador, Samoyed, and Boxer. Aortic stenosis is more common in large breeds such as the German Shepherd, Newfoundland, and Boxer.

How is a stenosis diagnosed?

Through physical examination, echocardiography, and sometimes additional ECG or CT scan.

Can a stenosis be cured?

Pulmonic stenosis can often be successfully treated with balloon dilation; aortic stenosis is harder to treat.

Is the prognosis good after treatment?

Often yes in mild cases, but severe stenoses carry an increased risk of complications.