Aortic Stenosis in Dogs

Aortic stenosis is a heart disease that is more common in certain dog breeds. Today, our Newtown vets discuss the causes, signs, diagnosis, and treatment of aortic stenosis in dogs.

Canine Aortic Stenosis

Aortic stenosis is the narrowing of the aortic heart valve. The aortic valve is the valve through which blood exits the heart and travels to the rest of the body. When this valve is narrowed, the heart must work harder to pump blood out through the valve. This additional work can have several harmful effects on the heart, leading to muscle failure and other complications.

Aortic stenosis can occur within the valve (valvular aortic stenosis), just above the valve (supravalvular aortic stenosis), or just below the valve (subvalvular/subaortic stenosis). Subaortic stenosis (SAS) is the most common form of these conditions.

Causes of Aortic Stenosis in Dogs

Aortic stenosis is a hereditary condition that occurs in certain breeds. The dog breeds that are most commonly affected by aortic stenosis include:

Signs of Aortic Stenosis

In many cases, affected dogs will not show signs or symptoms. Aortic stenosis is often initially detected on a routine physical examination when the vet detects a heart murmur. In moderate to severe cases, signs may be noted at birth; in mild cases, the murmur may not be noted until the dog is 6-12 months old.

In dogs with severe disease, you may observe signs related to heart dysfunction. Signs may include lethargy, exercise intolerance, shortness of breath, and fainting.

Signs of heart failure may be seen in severe cases of aortic stenosis. These signs include coughing, increased breathing effort, and open-mouth breathing. During heart failure, fluid will begin to pool in the lungs.

Heart failure is more common in dogs that have other heart valve problems occurring at the same time, but can be seen with aortic stenosis alone.

Diagnosing the Cause of Your Dog's Heavy Panting

The tests most commonly used to confirm a diagnosis of aortic stenosis include chest radiographs (X-rays), electrocardiography (ECG), and echocardiogram (ultrasound of the heart).

Routine laboratory tests (complete blood cell count, serum biochemistry, and urinalysis) will often be performed to assess your dog’s overall health. Having baseline laboratory values allows your vet to monitor your dog, especially if medication is required.

Treating Aortic Stenosis in Dogs

In mild cases of aortic stenosis, treatment typically is not necessary. Your dog may need to be closely monitored for signs of disease progression, but medication is not typically required. Exercise should also be restricted to aid in their recovery.

In moderate to severe cases, long-term medication may be required. Beta-blockers can be used to slow the heart rate and let the heart work more efficiently. In some cases, hospitalization may be required to ensure your pup's condition is under control.

Surgical procedures have also been considered and evaluated for use in aortic stenosis. This surgery is not commonly performed but may be necessary depending on the severity of your dog's disease, and your access to a cardiology specialist who is familiar with the procedure.

Exercise should be restricted in dogs with aortic stenosis, especially those with severe disease. The most significant health risk associated with aortic stenosis is sudden death. While this sudden death is not always correlated with exercise, strenuous exercise does appear to make it more likely.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. Please make an appointment with your vet for an accurate diagnosis of your pet's condition.