pets corner

Matters of the Heart by Dr Steph Gowing MRCVS

This month we’re taking the theme of Valentine’s Day and discussing matters of the heart - particularly heart murmurs. Some of you may have pets who have one and have had to undergo further testing. So what does it mean?

What is a heart murmur? It’s an abnormal sound in the heart heard when carefully listening with a stethoscope. This is often a ‘whooshing’ sound heard between the heartbeats. It is usually caused by abnormal blood flow (turbulence) within the heart or the blood vessels associated with the heart. This can be caused by faulty valves, changed heart muscle or a change of direction to blood flow.

What should I do if my vet has heard a murmur in my pet’s heart? If your pet is very young, initially the vet will monitor the heart sounds closely to see if the murmur disappears. Innocent (benign) murmurs can occur due to the fast flow of blood in a small heart. As the puppy or kitten grows and the heart matures these murmurs gradually disappear. They should usually disappear by six months of age. If the murmur is very loud or does not improve, your vet will recommend further investigation.

In older patients, the murmur is most often permanent. Usually a heart ultrasound scan will be recommended, which will allow the vet to look at the structure of the heart to see what changes have caused the murmur. A murmur is characterised by location, timing and a volume grade of 1-6. This allows vets to track any changes that may mean changes in the heart structure.

Why is my pet having a murmur important? As murmurs are usually related to changes in the heart, this means they are often a symptom of heart disease. Heart disease may stay stable and not impact the pet for a long time, or it may change and cause heart failure. This happens when the heart disease has progressed to the point where the heart is struggling to do its job and the pet may start showing symptoms. There are different stages of heart failure which is why it is important to scan these pets’ hearts before symptoms are obvious. Starting medication at the appropriate time, usually before symptoms appear, can significantly improve their lifespan.

What does more significant heart disease look like? Symptoms of advanced heart failure include: exercise intolerance, breathing problems, a cough, collapse, weakness, or pale gums. The earliest change that is often seen is an increase in the resting breath rate. This is the number of breaths your pet takes in one minute. It is important that this is taken when the pet is at rest and relaxed. If your pet has been diagnosed with a heart murmur and you notice any of the above signs please contact your vet.