Patent Ductus Arteriosus (PDA) Ligation

PDA is one of the most common congenital heart defects in dogs and is also seen in cats. Without repair, most patients develop left-sided congestive heart failure (fluid in the lungs) within one to two years, and median survival without surgery is poor. When surgery is performed early — ideally before signs of heart failure appear — the heart has the best chance to remodel back toward a normal size, and the animal can expect a normal lifespan. Even patients already showing early heart failure often benefit substantially from ligation once the cardiac function is stabilized medically beforehand.

PDA ligation is performed under general anesthesia with continuous cardiac monitoring by our team. The steps:

• An incision is made through the left side of the chest wall (thoracotomy), providing direct access to the heart and great vessels
• The ductus arteriosus is carefully isolated from the adjacent pulmonary artery and aorta
• The vessel is permanently tied off (ligated) with strong suture — blood flow through the shunt stops immediately
• The chest is closed in layers, and a small drainage tube is temporarily placed to remove any residual air before final closure

An echocardiogram (heart ultrasound) confirming closure is typically performed while the patient is still in hospital.

Before surgery, our cardiology team performs a full cardiac workup — echocardiogram, chest X-rays, and ECG — to assess the degree of heart enlargement and confirm surgical candidacy. Pre-anesthetic bloodwork is run to evaluate overall organ function. If early heart failure is present, a short course of diuretics and cardiac medications may be given first to stabilize the patient. You will be asked to withhold food the night before the procedure, and your pet will be admitted the morning of surgery for pre-operative preparation and IV catheter placement.

Hospital stay is typically two to three nights. At home, recovery focuses on the chest incision and respiratory comfort:

• Week 1: strict rest, incision monitoring, coughing or breathing changes reported promptly
• Weeks 2–4: gradually increasing quiet indoor activity; harness-only walks to avoid chest pressure
• 4–6 weeks: recheck echocardiogram to confirm the heart is remodeling and cardiac medications can be tapered

Most young patients who are repaired before heart failure develops make a complete recovery and require no ongoing heart medication. Patients with pre-existing cardiac enlargement continue cardiology follow-up to confirm the heart returns to normal size over several months.

PDA ligation has a high success rate when performed in experienced hands. The primary surgical risk is inadvertent vascular injury during dissection around the ductus — a rare event that our team is trained and prepared to manage. Other possible complications include recurrence of ductal flow (very uncommon with ligation), post-operative bleeding, or anesthesia-related issues. Patients with advanced heart failure carry a higher anesthetic risk, which is why early repair is strongly preferred. Our cardiology and surgical teams review every case together before proceeding, and owners receive a thorough informed-consent discussion before surgery.