BELLA had only come in for her annual vaccination and her owner seemed annoyed that it was taking more time than he had anticipated.

‘My wife normally brings her but she is unwell and I need to pick the kids up from school.’ Can you not just jag her with whatever she needs and let me tick this job off my list?’

To be fair, the poor chap did look a bit frazzled and it would have been easy to comply with his request. But there was a very good reason not to.

Bella is an eight year old Cavalier King Charles Spaniel and we know from experience that around two thirds of her breed will have a heart murmur by the time they reach this age.

Heart murmurs do not amount to a specific diagnosis, as there are many potential causes, but they are simply abnormal sounds that can be heard with the aid of a stethoscope. A normal heart, which is responsible for pumping oxygen-rich blood to the body, is composed of four chambers, separated by valves that open and shut in sequence, so that blood only flows one way.

Oxygen-poor blood returning from the body goes to the right atrium, then to the right ventricle and on to the lungs through the pulmonary valve. Oxygen-rich blood then flows to the left atrium which delivers it to the larger left ventricle through the mitral valve. The muscular left ventricle then pumps oxygenated blood to the body via the aorta.

In Cavaliers in particular, damage can occur to the mitral valve and this is referred to as Mitral Valve Disease (MVD).

Affected dogs can live for a very long time without showing symptoms but the condition is progressive, so that increased backwards leaking from the ventricle to the atrium occurs and more pressure is put on the heart.

Eventually, the murmur gets louder (we grade them from 1 to 6), the heart enlarges (cardiomegaly) and a variety of clinical signs develop. These include increased respiratory rate, tiredness, poor exercise tolerance, breathlessness, coughing and fainting.

Many moons ago, we would have noted the appearance of a symptomless heart murmur on the patient’s clinical record, advised the owner of the possibility of illness developing and suggested more regular heart checks, so that appropriate treatment could be started when signs of actual heart failure eventually occurred.

Now, however, research has changed our thinking on this.

The EPIC Study (evaluating the use of a drug called pimobendan in dogs with cardiomegaly) was carried out in 11 countries and involved treating one hundred and eighty dogs who had audible murmurs with the drug, compared to others who were given a placebo.

The results were so positive that the trial was terminated early, as it was deemed unethical to continue giving dogs the placebo alone. What it proved was that patients with MVD who were treated early had their average asymptomatic period extended by approximately fifteen months, resulting in them living longer and living better.

Which is why it was well worth ignoring Bella’s owner for a minute and reaching for that stethoscope.