What is atrial septal defect?

If your dog has an atrial septal defect, it has defect or hole in the wall the separates the left and the right atria of the heart. The heart consists of four chambers, and the left and right atria are two of them. The wall between heart chambers consists of muscles and is called the septum. When the dog is still an embryo, the heart consists of one single tube. This tube will then gradually separate into four chambers before the puppy is born. Defects can develop at several different steps of this process, and the result can be a small or big atrial septal defect in the heart of the dog. The exact effect on the dog will depend on how big the defect is and exactly where it is located.

Symptoms of atrial septal defect in dogs

If your dog has only a small atrial septal defect, it will probably show no symptoms of ASD at all. Your dog might however be extra susceptible to infections in the respiratory tract. If your dog has a large atrial septal defect, the situation is worse because such a defect will cause abnormal blood flow from the left side of the heart via the defect and into the right side. This makes the work load bigger for the right side of the heart, and this can in turn lead to right-sided heart failure which will be lethal without prompts treatment. Dogs with a large atrial septal defect can develop symptoms such as fainting, exercise intolerance, breathing difficulties, fainting, abnormal cardiac rhythms, and swelling. Right-sided heart failure can lead to sudden death. A dog with just a small atrial septal defect will on the other hand normally attain a normal age for its breed.  

When the vet examines a dog with an atrial septal defect, he or she will normally be able to hear a heart murmur. This heart murmur can be noticeable at a young puppy’s first physical examination.

Breeds commonly affected by atrial septal defect

Atrial septal defect (ASD) is a hereditary disease, but the exact mode of inheritance has not yet been discovered. Dogs with ASD should not be used for breeding, and neither should their parents. Siblings can be used for breeding, but only after meticulous screening. Atrial septal defect is an uncommon condition in all breeds, but the Boxer, Doberman pinscher, Old English bulldog, and Samoyed have an increased risk for ASD. 

Atrial septal defect treatment for dogs

As the signs of heart disease start to manifest in your dog, the vet can administer different types of treatment in order to alleviate the symptoms. The vet can prescribe drugs that will support the heart and decrease any congestion in the lungs. This should normally be combined with exercise limitations and a diet low in sodium.

In dogs with sever symptoms of heart disease; the vet can decide to surgically close the defect. This is a very risky procedure since it involves open heart surgery.

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Congestive heart failure in dogs
Degenerative mitral valve disease in dogs
Dilated cardiomyopathy in dogs
Heart valve dysplasia in dogs
Hemolytic anemia in dogs
Patent ductus arteriosus in dogs
Pericardial effusion in dogs
Pulmonary hypertension in dogs
Pulmonic stenosis in dogs
Thrombocytopenia in dogs
Ventricular septal defect in dogs
Atrial septal defect in dogs
Tetralogy of Fallot in dogs
Von Willebrand disease in dogs