Puppy Heart Disease

Heart Diseases Affecting Puppies

Miniature Poodles appear to have more issues with congenital heart problems. Image Copr. D-Base/Stockbyte/Getty Images

Puppies can be affected by a variety of heart problems. They can be congenital—present from birth—or acquired later in life, and some may be inherited. Heart failure results when the damaged muscle is no longer able to pump blood throughout the body properly. 

Signs of Puppy Heart Disease

Symptoms can be specific to the types of heart conditions. General signs can include the puppy quickly becoming exhausted from exercise.

Affected dogs with heart disease typically act weak or lethargic. They also may have a bluish tinge to the skin of the lips, tongue or inside the ears from lack of oxygen.

When the left side of the heart fails, fluid collects in the lungs (pulmonary edema) and results in a cough, labored breathing and panting. Dogs sit with elbows spread and neck extended while straining to breathe, and may even try to sleep in this position to ease breathing.

Right heart failure prompts ascites—fluid leaks from the body and collects and swells the abdomen, accumulates beneath the skin, and may fill the chest cavity (pleural effusion).  Accumulation of fluid causes congestive heart failure

Diagnosis of heart disease is made using X-rays, ultrasound and electrocardiograms that pick up irregular heart rhythms. Advances in cardiac treatment, including open-heart procedures, today give puppies and dogs a much greater chance to maintain a greater quality of life or even become cured.

Open Heart Surgery for Puppies

There are not many programs able to do open-heart procedures, and the technology is mostly limited to universities and teaching hospitals. Your veterinarian can refer you to a specialist if your puppy could benefit from these procedures.

Patent Ductus Arteriosus

The most common congenital heart disease, patent ductus arteriosus (PDA) affects Miniature Poodles and German Shepherd Dogs most often, but any pet may have the problem.

It may or may not be inherited. Normally, the ductus arteriosus, a short blood vessel, allows blood to bypass the lungs of an unborn puppy. If the duct fails to close after the puppy’s birth, blood leaks back into the heart through the opening and leads to left heart failure. Surgery can cure the problem when performed early, and in the past this has been the treatment of choice. “Young animals recover very well from thoracotomy, and for PDA that’s still a viable option,” says Dr. Orton. A thoracotomy opens up the entire chest wall to offer access to the heart, and then the hole is repaired.

Interventional catheterization is one of the most exciting techniques to reach veterinary cardiology, says Dr. Orton. “They treat coronary artery disease in people by going down in the coronaries with a catheter [flexible tube].” Coronary artery disease is not a major problem in animals, but the techniques have been developed for pets. Closure of PDA in pets can now be corrected using catheters. Pets recover more quickly with this procedure than thoracotomy, and other more invasive surgeries. Experts say that the more you can do with catheters, the less stress for the patient. 

Pulmonic Stenosis

Another heart problem of puppies is pulmonic stenosis, which means a narrowing of the connection between the right ventricle, or lower heart chamber, and the pulmonary artery that leads to the lungs. Affecting small breed dogs most often, this congenital defect makes the heart work harder to push blood through the narrow opening. Heart muscles sometimes compensate by growing stronger, but many times the heart defect becomes life-threatening.

New catheter techniques can also treat pulmonic stenosis, says Dr. Kittleson. Performed under anesthesia, the procedure requires a small incision into a blood vessel, and a catheter is passed through the vessel to reach the heart. “We put a fairly large catheter, with quite a large balloon on it, across this region of narrowing, inflate that balloon with some saline, and essentially rip the lesion apart,” he says.

That enlarges the opening to normal size. The procedure is identical to that performed on children with pulmonic stenosis. Heart catheterizations are specialized procedures, and only a few centers across the country do them. They tend to cost $1,000, says Dr. Kittleson.

Open-heart surgery offers a brand-new option for treating stenosis Dr. Daniel Brockman, now a surgeon at the Royal Veterinary College at the University of London, England. “A perfusionist comes from St. Luke’s Hospital in Bethlehem, Pennsylvania, to run the heart of the pulmonic valve. The technique can very successfully treat this congenital defect, but is currently limited to only two veterinary centers—University of Pennsylvania and Colorado State University. Patients must also meet stringent requirements to be considered as candidates.

Large breed dogs like Golden Retrievers are prone to aortic stenosis, a narrowing of the connection between the left ventricle and the aorta, the large artery that carries blood out of the heart. Surgery is the treatment of choice, but it is risky, expensive, and available only at veterinary schools or specialists that have access to cardiopulmonary bypass machines.

When the condition is one thought to be commonly found in your particular breed, ask the breeder about the history of the parents. Reputable breeders will do all they can to breed away from heart defects, whenever that's possible.