What are the common causes of pulmonary artery stenosis?

Pulmonary artery stenosis in dogs and cats can be caused by congenital valve or blood vessel abnormalities. It may also be associated with other heart diseases or structural changes, so a vet needs to assess the cause using imaging tests.

How can I monitor changes in symptoms at home?

Record breathing rate at rest and after exercise, activity level, and body weight each day. Take videos of episodes and note the timing and possible triggers to help your vet assess the pattern.

What imaging or tests are needed for diagnosis?

Chest X-rays, ECG, and echocardiography are usually performed first. CT or further specialist tests may be added if needed, based on your vet's recommendation.

How often is long-term follow-up needed for pulmonary artery stenosis?

Follow-up frequency depends on the severity of the condition. Stable cases are often checked every 6-12 months, while unstable pets or those with medication changes may need more frequent rechecks. Follow your vet's advice.

How much do the tests and treatment usually cost for this condition?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Pulmonary Artery Stenosis in Dogs and Cats: Breathing Signs, Imaging & Care [2025]

A congenital narrowing of the pulmonary artery that affects heart function

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: ACVIM, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

•Persistent severe panting that does not settle down
•Sudden fainting or brief loss of consciousness
•Gums or tongue turning purple or pale

Schedule a veterinary appointment as soon as possible (within 24-72 hours)

•Noticeable shortness of breath or panting after exercise
•Reduced activity tolerance and needing more rest
•Intermittent panting with changes in appetite or energy level

01What symptoms suggest something is wrong?

Pulmonary artery stenosis increases the workload on the lungs and heart. It often affects breathing and exercise tolerance, and early changes may be subtle.

Persistent or intermittent breathing difficulty or panting, often worse at night or after exercise
Noticeably rapid breathing after activity, with a longer recovery time
Abdominal swelling or ascites (fluid build-up in the abdomen)
Easy fatigue during activity, reduced stamina, or occasional fainting
Possible abnormal heart rhythm, dizziness, or low energy

Seek emergency care immediately if you notice the following symptoms:

⚠️ Severe breathing difficulty or pauses in breathing
⚠️ Sudden fainting or brief loss of consciousness
⚠️ Purple-blue or pale gums or tongue

02How can I assess abnormalities at home? Key monitoring points and when to seek emergency care

Monitoring breathing pattern, activity level, appetite, and toileting at home, then bringing notes or videos to the clinic, can help your vet assess the situation more quickly.

Record your pet's breathing rate at rest and after exercise each day, and note any open-mouth breathing or panting
Watch for changes in alertness, activity level, and exercise tolerance
Weigh your pet daily and record any noticeable gain or loss
Record appetite, water intake, and the frequency and character of urination and bowel movements
Take short videos of any episodes or abnormal breathing for reference
Bring your notes or videos to the vet visit, or share them during an initial phone consultation

03How will the vet diagnose it? Common tests

The clinic will start with a physical examination, then use imaging, ECG, and blood tests to assess heart and lung function and blood flow.

Physical examination

listening to the heart and lungs, and assessing murmurs and changes in breathing sounds

Chest X-rays

assessing heart size and lung changes or fluid

Electrocardiogram (ECG)

checking for abnormal heart rhythms

Echocardiography

assessing valves, blood flow velocity, and pressure effects

CT or advanced imaging

evaluating blood vessel anatomy or complex structural changes

Blood tests and biochemistry

assessing organ function and overall health

Referral to a cardiology specialist or interventional assessment if needed

04How is it treated and managed after diagnosis? Medication, diet adjustments, and care guidance

Treatment may include medication and lifestyle adjustments, while some cases need interventional procedures or surgery. Regular imaging and ECG follow-up are needed to monitor changes.

Medication treatment and adjustments require regular rechecks based on clinical response
Diet and weight management to reduce the workload on the heart
Avoid strenuous activity and overheating at home, and monitor resting breathing
Regular follow-up ECG, echocardiography, or chest X-ray checks
If the condition is clinically unstable, assess whether interventional treatment or specialist referral is needed
Arrange long-term monitoring to assess prognosis and quality of life

05What should I prepare before seeing the vet? Key details that help identify the cause quickly

Record when signs started, how often episodes occur, and what seems to trigger them

List all current medications, supplements, and past medical history

Take or prepare short videos of breathing and activity changes for the vet to review

Bring previous X-rays, ultrasound reports, or other test results if available

Record recent changes in appetite, drinking, urination, and bowel movements

Before the visit, consider calling ahead to book a cardiology appointment or explain the level of urgency

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.