The normal heartbeat makes a sound that corresponds to the closing of heart valves during the heart cycle. A heart murmur, caused by turbulent blood flow within the heart or large vessels that arise from it, sounds like an abnormal whooshing or swishing sound during the heart beat cycle. This can be heard with a stethoscope and, if loud enough, can be felt as a buzzing or vibration over the heart. Careful listening with a stethoscope to your cat’s heart by your family veterinarian is an important part of any physical examination.

What are the Possible Causes of Heart Murmurs in Cats?

Most heart murmurs in cats indicate underlying heart disease; however, the severity of that heart disease can vary significantly from cat to cat.  Some cats have what are known as flow or innocent heart murmurs, meaning that no structural heart disease is present.  It is important to note that such murmurs do not sound substantially different under stethoscope than do murmurs caused by severe heart disease. Thus, additional diagnostic testing is crucial to determine the underlying cause of a murmur in an individual cat. The most common structural heart diseases in cats are the cardiomyopathies or heart muscle diseases. The most common of these is known as hypertrophic cardiomyopathy (HCM), in which the muscle of the main pumping chamber becomes thicker (or hypertrophied) as compared to a normal chamber. Several other forms of cardiomyopathy exist, as well as a number of congenital (present from birth) heart defects. It is important to determine which disease an individual cat has and how severe it is in order to best tailor monitoring and treatment for the individual heart murmur patient.

What Can be Done to Determine the Cause of my Cat’s Heart Murmur?

The gold standard for diagnosing the cause of a cat’s heart murmur is a complete echocardiogram by a board certified veterinary cardiologist. The echocardiogram is an ultrasound of the heart that allows the cardiologist to examine the two-dimensional structure, pumping and relaxation function of the heart, and blood flow through the heart valves and great vessels. This is a completely non-invasive procedure, without pain, and completed without sedation in almost all patients.  The complete echocardiogram allows the cardiologist to determine the cause and severity of your cat’s heart murmur and also to guide treatment. Other diagnostic tests that may be indicated on a patient-by-patient basis include chest radiographs (X-rays), blood pressure measurement, ECG (for analysis of heart rhythm), and blood tests. These tests are complementary to but do not replace the echocardiogram.

What Treatment Options are Available for Cats with Heart Murmurs?

The treatment course for heart murmur depends entirely on the underlying heart disease identified by a complete echocardiogram.  Some cats have mild or no structural heart disease and require no treatment at the time of diagnosis.  Other cats have severe heart disease and will have a treatment regimen recommended that is tailored to their particular condition. Some cats, for example, have significant heart disease and underlying kidney disease, which requires the cardiologist to achieve a careful balance between these two systems.  All treatment protocols will be discussed at length with you, so that you are comfortable with your cat’s care.  You serve as a vital part of the team that strives to optimize your cat’s quality and length of life.

Our cardiology specialists work with your family veterinarian

A board-certified veterinary cardiologist has 4 years of specialized training beyond veterinary school and has passed a series of exams to achieve board certification. Our veterinary cardiologists work carefully with your family veterinarian and you to provide the best care of your cat. Much of the follow-up testing necessary can be performed at your family veterinarian’s office, with periodic follow up with your cat’s veterinary cardiologist. Our goal is to prevent or delay significant complications in cats with heart disease, such as congestive heart failure or severe lameness, and avoid stressful and more expensive emergency room visits.