Yes, patent ductus arteriosus (PDA) in dogs has a genetic component. It is classified as a complex, polygenic threshold trait, meaning multiple genes contribute to a dog’s risk rather than a single inherited mutation. Certain breeds develop PDA at significantly higher rates than others, which is strong evidence of heritability. If your dog has been diagnosed with PDA, or you’re a breeder trying to understand the risks, genetics plays a real role in this condition.
How PDA Is Inherited
PDA doesn’t follow a simple one-gene pattern like some inherited diseases. Instead, it’s polygenic, meaning several genes each add a small amount of risk. A dog inherits some combination of these risk genes from both parents, and when the total genetic burden crosses a certain threshold, the ductus arteriosus fails to close after birth. This is the same way many complex traits work: no single gene is “the PDA gene,” but the accumulated effect of many genes determines whether the defect appears.
This makes PDA harder to predict and harder to breed away from than a simple recessive condition. Two parents that appear perfectly healthy can still carry enough risk genes between them to produce affected puppies. And because the trait is influenced by a threshold effect, litters from the same parents may have different outcomes.
Breeds at Higher Risk
PDA is one of the most common congenital heart defects in dogs, and it clusters heavily in certain breeds. Miniature Poodles, Maltese, Pomeranians, Shetland Sheepdogs, English Springer Spaniels, Keeshonden, Bichon Frises, and German Shepherds are among the breeds most frequently affected. The Stabyhoun, a Dutch breed, has also been studied for its notably high PDA incidence.
The fact that PDA runs in breed lines is itself the strongest evidence for a genetic basis. Breeds are relatively closed genetic populations, so when a condition appears at disproportionately high rates in specific breeds but rarely in others, inherited factors are almost certainly involved.
The Female Predisposition
Across most breeds, female dogs develop PDA more often than males. This sex bias has been documented in both dogs and humans, though the reason for it remains unclear. One theory involves hormonal differences affecting how the ductus closes shortly after birth, but this hasn’t been confirmed.
Interestingly, not every breed follows this pattern. In a study of PDA in Stabyhouns, researchers found an equal split: 23 males and 23 females were affected, with no female predisposition at all. The sample size was large enough that a real sex difference should have shown up, so the absence was considered genuinely unusual. This suggests the genetic architecture of PDA may vary between breeds, with some breeds carrying risk factors that affect males and females equally.
What PDA Actually Is
Before birth, every puppy has a small blood vessel called the ductus arteriosus that connects the aorta to the pulmonary artery. This vessel is essential in the womb because the lungs aren’t yet in use, so blood needs to bypass them. Within the first few days after birth, the ductus normally closes on its own. In puppies with PDA, it stays open, allowing blood to flow abnormally between these two major vessels. This forces the heart to work much harder than it should.
If left untreated, most dogs with PDA develop congestive heart failure by one year of age. The heart progressively enlarges as it tries to compensate for the extra blood volume being shunted through the open duct, and eventually it can no longer keep up.
How PDA Is Detected
Most cases are caught during a routine puppy checkup. A veterinarian listening with a stethoscope will hear a very distinctive heart murmur, often described as a “continuous machinery murmur” because it sounds like a washing machine running constantly through both heartbeats. This sound is produced by blood flowing turbulently through the open duct and is different enough from other heart murmurs that it often raises immediate suspicion of PDA.
If the murmur suggests PDA, your vet will typically start with chest X-rays to look at the heart’s size and shape. An electrocardiogram (ECG) can reveal changes in the heart’s electrical activity that support the diagnosis. The definitive test is an echocardiogram, a cardiac ultrasound that lets a cardiologist see the open connection between the aorta and pulmonary artery in real time. According to Cornell University’s veterinary cardiology service, echocardiography is the test of choice for confirming PDA.
Treatment and Outlook
The good news is that PDA is highly treatable when caught early. There are two main approaches: traditional surgery to tie off the open vessel (called surgical ligation) and a less invasive catheter-based procedure where a small device is threaded through a blood vessel and used to plug the duct from the inside.
Both methods have excellent success rates. In comparative studies, the catheter-based approach showed no residual blood flow through the duct at one month, while surgical ligation had a very small residual shunting rate of about 1.5%. Major complications occurred in roughly 0.8% of catheter procedures compared to 3.1% of surgical cases. Neither approach carried operative mortality in the studied populations.
When PDA is corrected early, before the heart sustains significant damage, dogs can go on to live a normal lifespan. The key is timing. Because most untreated dogs develop heart failure within their first year, early detection during puppy wellness visits is critical.
What This Means for Breeding
Because PDA has a genetic basis, breeding decisions matter. The Merck Veterinary Manual states plainly that dogs with congenital heart defects where a genetic cause is likely or possible should not be bred. This applies not just to dogs diagnosed with PDA themselves but is worth considering for their close relatives as well.
The polygenic nature of PDA makes elimination through breeding more challenging than it would be for a single-gene disorder. You can’t simply test for a carrier status the way you can with some other inherited conditions. No specific genetic test for PDA risk currently exists. Instead, breeders in high-risk breeds rely on cardiac screening of breeding stock and careful tracking of which pairings have produced affected puppies.
If your dog has been diagnosed with PDA, spaying or neutering is strongly recommended to prevent passing on the genetic predisposition. If you’re a breeder and a puppy from one of your litters is diagnosed, both parents should be retired from breeding programs. Siblings of affected dogs also carry an elevated risk of passing on the relevant genes, so cardiac evaluation of littermates before any breeding decisions is a reasonable precaution.