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PDA: Is My New Puppy Tired Because of a Heart Problem?

Posted March 11, 2015 in Dog Diseases & Conditions A-Z

Collie puppy

Dr. Phil Zeltzman is a traveling, board-certified surgeon in Allentown, PA. His website is He is the co-author of “Walk a Hound, Lose a Pound” (

Freddy was a very cute 10-month-old Collie. He was cute, but he looked and acted very different from his littermates. He was reluctant to play and seemed to tire quickly—unlike his siblings who had unlimited amounts of energy. Freddy was a finicky eater with a stunted growth, which means that he was underdeveloped, compared to his littermates.

Freddy's guardian took him to his family veterinarian to try and figure out why he behaved that way. Everything seemed to check out normally during the physical exam, except for a loud heart murmur. An ultrasound of the heart, called an echocardiogram, was recommended. The ultrasound diagnosis was very clear: Freddy had a PDA.

What is PDA in a puppy?
PDA (which stands for Patent Ductus Arteriosus) is an abnormal vessel that connects two large arteries, right next to the heart: the pulmonary artery and the aorta. A PDA is a congenital abnormality, which means that affected dogs, and less commonly cats, are born with it. Some of the blood is directed away from the lungs and is not well oxygenated, causing weakness and low energy.

What causes PDA in a puppy?
This vessel is normal in the fetus and should shut down at birth. Since Mother Nature did not shut Freddy’s PDA off, human intervention was necessary. Without surgery, he would end up with heart failure. The surgery entails a thoracotomy, which means opening up the chest cavity. Doing this in less traumatic than it sounds. We go between two ribs, so there is no need to cut bones.

How is PDA treated in a puppy?
The next steps to treat a PDA are:

  • Confirm the PDA
  • Free it up and delicately place two stitches around it
  • These special sutures are tied to shut off the PDA and redirect the blood where it should go

This surgery can be quite risky and stressful for the surgeon. Whereas the two big arteries (the pulmonary artery and the aorta) are tough-vessel-blood-vessels, the PDA is a very fragile structure. The main risk of the surgery is in tearing the PDA, which can cause massive bleeding and possibly death of the patient.

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Dr. Phil Zeltzman is a board-certified veterinary surgeon and author. His traveling practice takes him all over Eastern Pennsylvania and Western New Jersey. You can visit his website at, and follow him at