Pulmonic Stenosis in Dogs: Causes, Diagnosis & Treatment

Pulmonic stenosis is a common congenital heart defect in dogs where the pulmonic valve narrows, restricting blood flow from the right ventricle to the lungs. This results in increased pressure on the heart and may cause serious health issues if untreated. Certain breeds, including English Bulldog puppies and Schnauzer puppies, are more susceptible due to hereditary factors. Responsible breeding is crucial to reduce the risk of this condition inheriting across generations.

Breeds Most at Risk of Pulmonic Stenosis

Pulmonic stenosis tends to be inherited in certain dog breeds. The most commonly affected include:

• French Bulldogs
• English Bulldogs
• Boxers
• Beagles
• Boykin Spaniels
• Various Terrier breeds, including Schnauzers

Owners of these breeds should be vigilant about heart health checks and avoid breeding affected animals to prevent passing on the defect.

Recognising the Signs and Symptoms

Symptoms can vary depending on the severity of the stenosis. Mild cases might remain asymptomatic throughout life, while severe cases show symptoms early. Signs to watch for include:

• Exercise intolerance or reluctance to play
• Weakness or collapse, often triggered by excitement or stress
• Fatigue during physical activity
• Breathing difficulties or coughing in advanced stages

Early detection during routine veterinary checks, especially the presence of a heart murmur, is key to timely intervention.

How Pulmonic Stenosis Is Diagnosed

If a vet detects a heart murmur or suspects heart issues, referral to a veterinary cardiologist is usually recommended. Diagnosis involves several tests to assess the heart and valve function:

• Echocardiography (Heart Ultrasound): The most important test, using Doppler to visualise the pulmonic valve and blood flow.
• Chest X-rays: Reveal heart size and shape changes due to the condition.
• Electrocardiography (ECG): Helps detect heart rhythm abnormalities though it's less definitive than ultrasound.
• Angiocardiography: A specialised X-ray with dye to highlight valve stenosis, sometimes used for detailed evaluation.

Current Treatment Options for Pulmonic Stenosis

Though there is no cure for pulmonic stenosis, treatments aim to reduce obstruction and support heart function. Options include:

• Medical management: Beta blockers, such as atenolol, help protect the heart and reduce arrhythmia risks.
• Balloon valvuloplasty: A minimally invasive procedure where a balloon catheter is inserted to widen the stenotic valve. Typically performed by specialists, this treatment improves blood flow and quality of life in about 80% of cases.
• Other interventions: For complex cases, pulmonary artery stenting or surgery may be considered but come with higher risks.

Ongoing monitoring by a vet and specialist is essential post-treatment to manage the condition effectively.

Associated Conditions with Pulmonic Stenosis

Dogs with pulmonic stenosis often have additional cardiac defects that require consideration:

• Aortic stenosis: Narrowing of the aortic valve impeding blood flow from the left heart to the body.
• Ventricular septal defect: A hole in the wall between the heart’s ventricles causing abnormal blood flow.

These may complicate treatment and prognosis, so comprehensive cardiac evaluation is vital.

Living with and Caring for a Dog with Pulmonic Stenosis

Regular veterinary follow-ups are crucial to monitor progression and manage symptoms. After balloon valvuloplasty, the first check-up is typically at three months post-procedure, then annually if stable. Owners should provide a calm environment, avoid excessive excitement or strenuous exercise, and observe for any changes in breathing or behaviour.

Early diagnosis and specialist care can significantly improve a dog's quality of life and longevity with this condition.

What You Need to Know About Responsible Breeding

Since pulmonic stenosis is hereditary, dogs diagnosed with the condition should never be bred. Ensuring future generations are free from this heart defect includes screening breeding dogs, supported by veterinary cardiology advice. Prospective puppy buyers should seek reputable breeders who perform health testing to minimise inherited diseases.

Frequently Asked Question: What Causes Pulmonic Stenosis in Dogs?

Quick Answer: Pulmonic stenosis is a congenital defect mainly caused by malformation or fusion of the pulmonic valve leaflets, restricting blood flow from the heart to the lungs and is often inherited in specific dog breeds.

The condition usually develops before birth due to abnormal heart valve formation, and genetics play a significant role, particularly in predisposed breeds such as English Bulldogs and Boxers. Environmental factors have less influence compared to heredity. Understanding this cause supports the importance of responsible breeding to reduce incidence.

Frequently Asked Question: How Is Pulmonic Stenosis Treated?

Quick Answer: The preferred treatment for moderate to severe pulmonic stenosis in dogs is balloon valvuloplasty, a minimally invasive procedure to widen the narrowed valve, improving blood flow and heart function.

Treatment aims to reduce the obstruction caused by the narrowed valve, easing the workload on the right ventricle. Medical management with beta blockers can help control symptoms, but balloon valvuloplasty performed by veterinary cardiologists offers the best improvement. Some cases may require pulmonary artery stenting or ongoing medical care if surgery isn’t suitable.

Frequently Asked Question: Can Dogs Live Normal Lives with Pulmonic Stenosis?

Quick Answer: Many dogs with mild pulmonic stenosis live normal, unaffected lives, but dogs with severe stenosis benefit greatly from treatment like balloon valvuloplasty and careful monitoring to improve quality of life.

The prognosis depends on stenosis severity. Mild cases might show no symptoms and normal lifespan. For moderate to severe cases, interventions improve survival and reduce heart strain. Regular veterinary check-ups and avoiding strenuous activity help maintain wellbeing.