Patent Ductus Arteriosus (PDA)

Patent ductus arteriosus is a congenital anomaly of the heart which causes fluid build-up in the lungs, exercise intolerance and possibly death if left untreated. During normal fetal development, the ductus allows most of the blood in the pulmonary artery to by-pass the lungs and go into the aorta. In normal animals, the ductus should close shortly after birth. Dogs with a PDA can be successfully treated surgically.

PDA is one of the most common congenital cardiac defects in dogs. It also occurs in humans. A characteristic “machinery” murmur is usually heard by a veterinarian on physical examination. In one retrospective study (Ackerman, 1978) of 537 dogs with PDA, Miniature and Toy Poodles, Pomeranians, and Shetland Sheepdogs were identified as being of high risk for PDA. Although PDA is considered to be an inherited defect in most affected dogs, the mode of inheritance is complicated and not well understood. Additional information on PDA is can be found at:

Dr. Kathryn Meurs of North Carolina State University is a veterinary cardiologist and the director of the NCSU Veterinary Cardiac Genetics & Holter Laboratories. In addition, she is the Associate Dean of Research at NCSU. Dr. Meurs is interested in studying the genetics of PDA in Shetland Sheepdogs and other breeds. PDA description 2016 for more information about her research and how to participate.


Ackerman N, Burk R, Hahn AW, Patent ductus arteriosus in the dog: a retrospective study of radiographic, epidemiologic, and clinical findings. Am J Vet Res, 1978; 39:1805-10.