What causes patent ductus arteriosus?

Patent ductus arteriosus is a congenital cardiovascular abnormality. It usually occurs when a foetal blood vessel fails to close after birth. The exact cause is linked to genetic or developmental factors, so ask your vet about your pet's individual risk.

How can I confirm whether my pet has patent ductus arteriosus?

Your vet may first detect a heart murmur during auscultation, then use chest X-rays and echocardiography to confirm the ductus location and blood flow. Echocardiography is the main diagnostic tool.

Does patent ductus arteriosus need surgery?

In most clinical cases, vets recommend occlusion or surgical ligation. Whether surgery is appropriate depends on the severity of the defect and your pet's overall health, with the final decision made after veterinary assessment.

What is my pet's prognosis after treatment?

If occlusion or surgery is performed in time and there are no serious complications, many pets have a clear improvement in quality of life. Long-term monitoring of heart function is still needed, with follow-up visits as recommended by your vet.

How much do the tests and treatment usually cost?

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

Disease Guide

Patent Ductus Arteriosus in Dogs and Cats: Breathing Difficulty, Echocardiography & Care Guide [2025]

A congenital heart defect that may require surgical ligation of an abnormal blood vessel

Take 1 minute to check the symptoms first

Last updated: 2025/12/16

Pethealthmap Editorial Team

Sources: ACVIM, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate emergency care

•Difficulty breathing with open-mouth breathing that cannot be relieved
•Gums or skin turning visibly purple or blue
•Repeated seizures or brief loss of consciousness requiring emergency care

Schedule a clinic visit soon (within 24–72 hours)

•Noticeable shortness of breath or fatigue after exercise or activity
•Frequent coughing or rapid breathing while at rest
•Decreased appetite, reduced alertness, and noticeably lower activity level

01What symptoms suggest something is wrong?

Common signs of patent ductus arteriosus are usually related to increased strain on the heart and lungs. Some signs are chronic, while severe cases may show emergency warning signs.

Persistent or night-time coughing; record the frequency and when episodes occur
Weakness, breathlessness, or reduced exercise tolerance after activity
Rapid breathing at rest or during activity should be monitored closely
Low energy, reduced appetite, or a clear drop in activity level
Occasional seizures or brief episodes of collapse should be assessed by a vet promptly
Blue-purple gums or skin (cyanosis) are an important warning sign

Seek emergency care immediately if you notice the following symptoms:

⚠️ Difficulty breathing or open-mouth breathing that does not improve
⚠️ Gums or skin turning clearly blue-purple
⚠️ Repeated seizures or brief fainting episodes need immediate care

02How can you assess the problem at home? Key observations and when to seek emergency care

Before visiting the clinic, observing and recording details at home can help your vet understand how the condition is changing.

Record coughing frequency, timing, and possible triggers
Observe and note changes in breathing rate at rest and during activity
Use your phone to record short videos of coughing or abnormal breathing for the vet
Track changes in energy, appetite, and water intake
Note toileting frequency and colour, and whether there are any other abnormal discharges or eliminations
If signs worsen, arrange a vet appointment or emergency visit as soon as possible

03How will the vet diagnose it? Common tests

Vets mainly use a physical examination and imaging to assess heart function and whether the lungs are affected.

Physical examination

listening to the heart, assessing murmurs, and checking breathing sounds

Chest X-rays

assessing heart size, pulmonary oedema, or lung changes

Echocardiography

assessing the ductus location, blood-flow direction, and heart structure

Blood tests and biochemistry

checking organ function and anaesthetic risk

Electrocardiogram (ECG) and, when needed, advanced imaging such as CT

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

Treatment is usually based on occlusion or surgery. Close monitoring after the procedure and long-term follow-up of heart function are important.

Depending on the case, treatment may involve transcatheter occlusion or surgical ligation
During hospitalisation, oxygen support and vital-sign monitoring may be needed
Post-operative medication or supportive care will be provided based on the vet's assessment
Manage diet and body weight to help reduce strain on the heart and lungs
Attend regular follow-up visits, with imaging used to monitor changes in heart function
Continue monitoring breathing, activity level, and appetite at home, and update the veterinary team

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

Record when signs first started, how they have changed, and any worsening

List current medicines, supplements, and any allergy history

Bring videos of coughing or abnormal breathing for the vet to assess

Bring any existing X-rays or other test reports, if available

Prepare recent notes on toileting and food intake for the vet to review

Travel in a secure carrier or crate, and share your observation notes when you arrive

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.