A heart murmur is an extra vibration (with an audible noise) that is caused by a blood flow disturbance. Usually, these are classified by a number of different characteristics, which include their timing.
Types of Heart Murmurs and Other Symptoms
The symptoms of heart murmurs depend on their different grades, locations and configurations. However, if a murmur is associated with structural heart disease, your pet may show signs of congestive heart failure which include exercise intolerance, weakness and coughing.
What Are the Causes of Heart Murmurs in Pets?
Pets can get heart murmurs from:
• Disturbed blood flow that is associated with high flow caused by normal or abnormal valves or with structures that vibrate in the blood flow.
• Blood flow disturbances that are from outflow obstruction or forward flow through diseased valves or into a dilated great vessel.
• Blood flow disturbances that are associated with a regurgitant flow from an incompetent valve, defect in the septum or patent ductus arteriosus.
Additionally, murmurs can be brought on by these diseases and conditions:
• Pulmonic stenosis
• Aortic stenosis
• Dynamic subaortic stenosis
• Mitral and tricuspid valve heart failure
• Cardiomyopathy and aortic valve insufficiency
• Mitral and tricuspid valve dysplasia
• Heartworm disease
• Systolic anterior mitral motion (SAM)
• Dynamic right ventricular outflow obstruction
• Mitral and tricuspid valve endocarditis (inflammation of the inner part of the heart)
• Atrial and ventricular septal defect
• Tetralogy of Fallot
Diagnosing Heart Murmurs in Pets
For a veterinarian to determine what is causing heart murmur symptoms, they must identify the wide range of abnormal heart sounds which include ejection sounds, gallop rhythms, clicks and split sounds. The doctor also must differentiate between abnormal heart and lung sounds and also listen to check if the timing of an abnormal sound is correlated with heartbeat or respiration.
Another way to determine the cause of heart murmurs is the radiation and location of the murmur as well as the timing during cardiac cycle. This is accomplished through different tests which include echocardiography, chest X-rays and Doppler studies. Also, a complete blood count is one of the recommended methods for confirming heart murmurs.
Treatment for Pets with Heart Murmurs
Your pet will be treated as an outpatient unless heart failure is evident. This treatment will be determined on associated clinical signs. For puppies or kittens with low grade murmurs, they may need little or no treatment and the murmur may resolve itself within six months. For pets with murmurs, diagnostic imaging is recommended.
At PAVG, we are always committed to making sure your pet stays happy and healthy. If you suspect your pet may have a heart murmur, or if you notice any of the above symptoms, please contact us at our following locations: