About Heart Murmers

There are many diseases which can cause a murmur. The most common one in dogs is mitral valve disease (MMVD), but other causes include dilated cardiomyopathy (DCM), aortic and pulmonic stenosis, patent ductus arteriosus (PDA), and ventricular and atrial septal defects - holes in the heart. The most common heart disease that causes murmurs in cats is hypertrophic cardiomyopathy (HCM), although not all cats with HCM have a murmur. Other causes in cats include DCM, congenital tricuspid and mitral valve disease, and restrictive and unclassified cardiomyopathies.

While a murmur indicates that there may be a problem with the heart, it doesn't tell you the cause of the heart disease, or how serious it is. It may be the first symptom of a potentially serious problem. Therefore it is important to do further testing to determine what's going on. If your pet is showing additional signs of heart disease - such as changes in their breathing, changes in their energy levels, or fainting - it is very important to investigate their problems without delay.

The gold standard test for investigating a heart murmur is echocardiography. This may also be called an 'echo' or a 'heart scan'. This is where ultrasound is used to look at the internal heart structures and movement of the valves. Doppler echo can directly show the movement of blood within the heart chambers and great vessels, and helps to assess all aspects of heart function.

Echo is the only way to determine the exact cause of your pet's murmur. It also helps us to assess the severity of heart disease, what the best treatments will be, and your pet’s prognosis. We use it to monitor your pet’s response to treatment.

Echo is a completely non-invasive and safe test, and most pets do not need any sedation for it.

Your vet may also recommend radiography of the chest (chest x-ray). This is useful to assess the lungs, the blood vessels in the chest, and the overall size and position of the heart. Radiography can help determine whether your pet is in congestive heart failure or not. Mild sedation may be necessary for this test; your vet can advise.