Heart Defect (Congenital) in Dogs

Patent ductus arteriosus is a congenital heart defect in which the vessel of the heart known as the ductus arteriosus is abnormally functioning. When a puppy is in utero he does not yet use his lungs for breathing. The pulmonary artery takes blood through the ductus arteriosus to the aorta. Once the puppy is born, this vessel closes so the blood may now go into the lungs to exchange oxygen. Patent ductus arteriosus is a condition where the vessel, the ductus arteriosus, does not close and as a result some of the blood does not enter the lungs. The puppy then does not receive an adequate amount of oxygen. Depending on the severity of the puppy’s condition, this heart defect may be quite treatable or can prove fatal. There are effective treatment options; however, not all puppies respond the same to treatment options for heart defects.

Heart defect (congenital) in dogs, known as patent ductus arteriosus, is a defect in the vessel of the heart known as the ductus arteriosus. It occurs in puppies shortly after birth to within the first few months after birth.

One of the first signs of patent ductus arteriosus, or PDA, is inactivity. Other symptoms may worsen over time, especially if the puppy is untreated. Symptoms of PDA include:

• Shortness of breath
• Inability to exercise
• Coughing
• Weakness
• Lethargy
• Stunted growth

Types

There are several different types of heart defects in dogs, some of them being congenital, and some of them developed over time. Other heart defects that may have similar symptoms to patent ductus arteriosus include:

• Pulmonic stenosis
• Ventricular septal defect
• Aortic stenosis

PDA is a birth defect of the heart. Puppies that are in utero have a system that is functioning normally; however, once they are born the heart circulation does not adapt to the bodily changes after birth. This birth defect is caused by:

• Genetics
• Abnormal heart circulation after birth

Puppies that are born with PDA show no signs at first. They appear as healthy puppies that may be a little smaller than the littermates. This is why it is important for routine examinations to be completed as the puppies are born. The veterinarian will perform a normal checkup of the litter, and if a puppy, after listening to its heart, has a heart murmur the veterinarian will want to take a closer look.

If the veterinarian suspects there is a heart issue, imaging of the chest area will be completed. X-rays of the heart and lungs will give the veterinarian a closer look at the shape and size of the heart and lungs. An electrocardiogram will measure the heart’s electrical impulses inactivity and will pick up any heart abnormalities in terms of rhythm. A cardiac ultrasound, known as an echocardiogram, will be the definitive test for PDA. This is because an image is shown of the heart in real time and will allow the medical professional to see that the aorta and the pulmonary artery are not communicating properly.

There is one method of treatment for patent ductus arteriosus, and that is to completely close the vessel (ductus arteriosus). Treatment plans include:

Invasive Surgery

A thoracotomy is an invasive surgery where the chest is opened so the surgeon can go in and close the ductus arteriosus.

Non-Invasive Surgery

A more desirable procedure for some is the use of a catheter. Catheter-based blocking or occlusion allows the surgeon to completely close the vessel with a coil-like tool.

Once the diagnosis of PDA is definite, it is important for the dog to receive either of these treatment options. Both of these procedures are performed by a cardiac veterinary surgeon.

With every diagnosis of PDA, every dog is different as is the method of surgery and the time it takes to heal. The prognosis varies depending on the puppy and the severity of his condition. There are times where PDA is quite treatable, and there are some instances where PDA leads to a shortened lifespan. Once the puppy is home from a thoracotomy, he will need to go back to the veterinarian to have the sutures removed in approximately one week. For either type of surgery, the dog will have a recovery which will entail you to keep an eye on the bandages or wrapping by keeping the area clean and making sure the dog does not do anything to compromise the incision.

If your dog has been prescribed any medications to take, either on a short-term basis or long-term basis, be sure to administer the medication appropriately and on a schedule. The veterinarian will give you specific instructions on how to care for your dog after the procedure and will let you know of any symptoms that warrant an immediate veterinary visit. It is important to keep any appointments after the procedure to be sure your dog is healing properly.