What is a heart murmur?

A heart murmur is an abnormal heart sound, usually caused by turbulent blood flow within the heart. Normally when we listen to the heart, we hear the ‘lub-dub’ sound – this indicates the closing of the 2 types of valves within the heart. If there is a murmur, we will often hear a whooshing sound between the ‘lub’ and the ‘dub’. However, this is not always the case, there are lots of variations in the timing, location, frequency, and pitch of heart murmurs – some of which give us an idea of the underlying cause. We cannot assess the severity or impact of the murmur from the sound alone and may recommend further investigations

Causes of heart murmurs

  • Leaky heart valves
  • Changes to the structure of the heart
    • Congenital (born with it)
    • Acquired
  • Anaemia
  • Hypertension (high blood pressure)
  • Hyperthyroidism
  • Innocent flow murmurs
  • Stress

When to worry?

Heart murmurs will often be identified during a routine health check. If this is the case – do not panic! Your vet will take a thorough history and check for other signs of heart disease. They will then discuss what the most likely cause of your pet’s heart murmur is and what investigations and/or treatment is recommended.

It is likely that an echocardiogram will be recommended. This is an ultrasound scan of the heart and is normally performed without sedation on a day-patient basis. Most animals tolerate this extremely well.

Some heart conditions will require medications or even surgery whereas others may require simple monitoring.