Pulmonic Stenosis in Dogs

Pulmonic stenosis in dogs has been identified as the third most common congenital disease in dogs. While there are treatment options available for pulmonic stenosis, it is important to understand what this congenital defect is and how treatment can increase the longevity of a dog’s life.

Pulmonic Stenosis Explained

Within the heart, dogs have four valves which control the flow of blood in and out of the heart. These valves include the mitral valve, aortic valve, pulmonary valve and tricuspid valve. Each of these valves has flaps which open and close to keep the flow of blood sufficient within in the heart and moving in the appropriate direction.

The pulmonary valve, or pulmonic valve, is located between the right ventricle and the pulmonary artery. Its main function is to move blood from the right ventricle through the pulmonary artery and into the lungs where the blood can then be oxygenated. Stenosis of the pulmonary valve means that the pulmonary valve is too narrow to allow for adequate blood flow, which restricts the amount of blood pumped into the lungs.  

In dogs, pulmonic stenosis is a condition that occurs during development while in utero. It is not known exactly what causes this condition, but there does appear to be a genetic link involved.

Signs and Symptoms of Pulmonic Stenosis

Pulmonic stenosis in dogs is a serious condition, although it may or may not require medical treatment. However, because blood flow to the lungs is restricted, it is important to recognize the signs and symptoms so that can treatment can be sought and identified if needed.

Signs and symptoms include:

  • Shortness of breath at rest or with minimal activity
  • Heart murmurs sounds upon auscultation of the lungs
  • Excessive fatigue and lethargy
  • Appearance of generalized pain and malaise
  • Loss of consciousness
  • Abdominal distention (fluid retention)

It is important to note that some dogs may only experience very mild variations of these symptoms. However, even though the symptoms may be mild in nature, they are still worthy of veterinarian examination.

Diagnosis and Treatment of Pulmonic Stenosis

Diagnosing pulmonic stenosis in dogs begins with a thorough physical examination. Although an ultrasound done during pregnancy could identify the possibility of a heart abnormality, pulmonary stenosis in dogs may not be definitively diagnosed until after birth. When heart murmurs (swishing sounds) are heard upon listening to the chest, it indicates that blood may be moving more freely within the heart as a result of a defective heart valve. These sounds then prompt further examination with echocardiography, or ultrasound imaging of the heart. An echocardiographic image of the dog’s heart allows for the visualization of pulmonic stenosis, as well as whether or not the right ventricle is enlarged as a result.

Some dogs may not experience severe enough symptoms to prompt medical intervention. While stenosis cannot be corrected without surgery, stenosis of the pulmonary artery does not always cause problems major enough to warrant surgical intervention. However, for dogs requiring surgery, a balloon valvuloplasty can be done. This procedure is done by inserting a balloon catheter into the pulmonary valve where it is then inflated to allow optimal blood flow.