Congenital vs Acquired Heart Disease in Dogs

When it comes to heart disease in dogs, there are two possible conditions that might occur. The first one is a congenital condition that the dog is born with, and the second one is an acquired condition developed later in the dog’s life. Answering this question is difficult because of the numerous elements that affect it, yet some clues might help to achieve a better understanding.

For instance, congenital heart disease is often found in purebred dogs from specific breeds and pedigrees. There are also some known risk factors for both types of heart disease- namely exposure to toxins and lack of exercise- so it may be possible to reduce your dog’s risk for either by making simple lifestyle changes.

What Causes Congenital Heart Disease?

Congenital heart disease is the general term for an issue that arises during fetal development, which prevents your dog’s organs from growing into their ideal location. For instance, maybe the heart is located too low in the chest cavity and isn’t pumping blood properly; or perhaps there’s too much fluid around the heart, which obstructs blood flow.

Common congenital heart diseases include:

Patent Ductus Arteriosus (PDA): This occurs when a puppy’s pulmonary artery fails to close during its development in utero. As such, oxygenated and deoxygenated blood mixes; it isn’t severe in most dogs and will complete on its own within a few weeks, but it can lead to heart failure.

Tetralogy of Fallot: The pulmonary valve is blocked or narrowed, which causes less oxygenated blood to reach the lungs. In addition, there’s a hole between two chambers that reduces pressure, which leads to blood flowing backward during diastole.

Coarctation of the Aorta (CoA): This occurs when there is a narrowing in the aorta, making it harder for the heart to pump blood to your dog’s body; in addition, many dogs suffer from an additional hole between two chambers of the heart.

Subaortic Stenosis: A thickening of your dog’s aortic valve leads to high blood pressure and makes it difficult for blood to flow out of your dog’s heart; in severe cases, there is an obstruction in the left ventricle.

These common congenital heart diseases are usually diagnosed during the first six weeks of your puppy’s life. If possible, breeding dogs with these issues should not be used.

What Causes Acquired Heart Disease?

Acquired heart disease is the general term for an issue that arises due to stress on the heart or blockage of blood flow. There are several different causes of acquired heart disease:

Hypertrophic Cardiomyopathy (HCM): A thickening of your dog’s heart muscle makes it harder for the heart to pump blood and increase pressure within its chambers. In most dogs, the cause is unknown, but some breeds have a genetic component. This can lead to sudden death in otherwise healthy dogs.

Aortic Stenosis: A thickening of your dog’s aortic valve leads to high blood pressure and makes it difficult for blood to flow out of your dog’s heart; in severe cases, there is an obstruction in the left ventricle.

Myxomatous Mitral Valve Disease (MVD): An inherited condition is common cause of acquired heart disease in dogs. The mitral valve becomes floppy and doesn’t close properly; blood flows through the valve when it shouldn’t, leading to congestive heart failure.

Coronary Artery Disease (CAD): When the heart’s blood supply is limited or blocked, which causes slow tissue damage and eventually congestive heart failure

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): In this condition, the right ventricle of your dog’s heart weakens and enlarges, resulting in abnormal heart rhythms and congestive heart failure.

Regardless of the underlying cause, acquired heart disease can be seen in dogs of all ages, breeds, and sexes.

Congenital versus Acquired Heart Disease in Dogs

To date, no conclusive research shows one form of heart disease is more common than the other in dogs. This is because many different breeds, sizes, ages, etc., are involved in studies.

However, specific findings have been published that give clues about the frequency of congenital versus acquired heart disease. For instance:

  • A 2000 study found that 64% of dogs who died from heart disease were less than five years old, with the most common cause being HCM.
  • According to Veterinary Partner, three-quarters of dogs diagnosed with congestive heart failure (CHF) are seven years or older.
  • Researchers at Auburn University found that 8% of dogs who died suddenly were younger than one year, and CHF was the most common form of heart disease.

With this information, it appears that acquired heart disease is more common than congenital in dogs, but again it’s challenging to be sure given the number of factors involved.

There are several steps you can take to help your dog avoid developing either form of heart disease:

  • Ensure your dog always has plenty of freshwaters to drink.
  • Feed your dog a properly balanced diet, not table scraps or junk food.
  • Do not let your dog become overweight; check your vet for the best weight/age recommendations.
  • Give your dog routine veterinary check-ups.
  • Keep your dog’s vaccinations up to date.
  • Exercise your dog daily, but ensure you know any signs of heart disease before beginning a strenuous workout regimen.

Whichever form of heart disease affects your dog, and early detection is key to successful treatment and improving prognosis. If you notice any symptoms or signs of heart disease in your dog, contact your veterinarian as soon as possible.

What are the symptoms of heart disease?

The primary symptom is shortness of breath. Dogs with congestive heart failure have difficulty breathing due to increased fluid build-up within their lungs and around their hearts. They might gulp for air, have a swollen abdomen from fluid build-up, or sit or stand with their elbows spread apart. Other signs include loss of appetite and excessive panting.

In HCM, there might be no symptoms in the early stages, but if the heart is enlarged secondary to high blood pressure, you might see signs of lethargy, coughing, difficulty breathing, or collapse.

With ARVC, the most common sign is sudden death due to abnormal heart rhythms with no warning signs. Other symptoms include lethargy, loss of coordination, and collapsing unexpectedly. If your dog has any of these symptoms, contact your veterinarian without delay. Treatments are available for all forms of heart disease if caught early enough.

Though the exact cause is unknown, certain risk factors are known to contribute to heart disease in dogs:

  • Acetaminophen toxicity
  • Exposure to toxins such as lead, thallium, mercury, and arsenic, since many of these toxins are especially dangerous for puppies, please do not allow your dog to chew or eat anything he finds outdoors.
  • Lack of exercise. Sedentary dogs are at risk for obesity, contributing to heart disease.

There are steps you can take to reduce the risk of either congenital or acquired heart disease in your dog:

  • Ensure that your dog has plenty of freshwaters to drink.
  • Feed your dog a properly balanced diet, not table scraps or junk food.
  • Do not let your dog become overweight; check your vet for the best weight/age recommendations.
  • Give your dog routine veterinary check-ups.
  • Keep your dog’s vaccinations up to date.
  • Exercise your dog daily, but ensure you know any signs of heart disease before beginning a strenuous workout regimen.

If the symptoms of heart disease do appear in your dog, contact your vet without delay for treatment options. If caught early, heart disease is treatable.

Early detection is key to successful treatment and improving prognosis for whichever form of heart disease a dog has.

Conclusion

Heart disease is the most common cause of death in dogs but can be prevented with lifestyle changes. The first step to preventing heart disease is ensuring your dog has plenty of fresh water and a well-balanced diet without table scraps or junk food.

It would help keep an eye on his weight; make sure he doesn’t become overweight by checking with your veterinarian for the best weight/age recommendations. If you notice any heart disease symptoms, contact your vet as soon as possible–treatments are available for all forms if caught early enough! Whichever form causes more trouble for your dog (congenital or acquired), these steps will help reduce their risk factor:

  • Ensuring they have lots of fresh water daily
  • Exercise but stay aware of heart disease symptoms
  • Giving routine veterinary check-ups

These are especially important for dogs with congenital heart disease because early diagnosis can be life-saving.