Cavalier King Charles Spaniels and Heart Murmurs
Finding a heart murmur when examining a Cavalier King Charles Spaniel (CKCS) is very common. In fact, by five years of age over 50% of CKCS’s have a heart murmur, and by ten years of age almost all will have a murmur.
What Causes the Murmur?
The most common cause of this murmur is a disease called endocardiosis (it is also called mitral valve disease, mitral valve degenerative disease, chronic valvular disease, and myxomatous mitral valve degeneration). It is caused by a degeneration of the mitral valve (the valve between the left atrium and left ventricle of the heart), and can lead to a condition called congestive heart failure.
We don’t understand why the valve degenerates in such dogs, but it is very common in breeds such as CKCS’s, Poodles and Terriers.
Your Vet will check your dog’s heart at their annual health check. We find in most cases, the Vet will initially find a low grade heart murmur. We grade them from Grade 1-6, with grade 1 being a very subtle murmur and grade 6 being so pronounced you can actually feel it just by putting your hands on the dog’s chest.
As a general rule, the loudness of the murmur will give a good idea of how bad the valve degeneration is, with a louder murmur normally indicating a more damaged valve.
The function of the valves in the heart is to make sure the blood is pumped in the right direction. When the valves become leaky, some of the blood is pumped in the wrong direction. This leads to increased pressure in the blood vessels leading to the heart, and changes to the heart muscle itself as it tries to compensate for the leaky valve. This process leads to congestive heart failure.
The first signs many owners will notice is the dog having a cough. This is a sign that there is an increase in pressure in the small blood vessels in the lungs and congestive heart failure has set in.
What are the Treatment Options?
Until very recently, the advice was to start treatment once the dog was showing signs of congestive heart failure, such as coughing or struggling to exercise. We believed that early treatment didn’t improve the outlook for the dog.
Late last year, the results of a massive trial were published, which has changed this advice. It has shown that starting treatment earlier can delay the onset of clinical signs of heart failure by 15 months. The results of the study can be found here: http://www.results.epictrial.com/
So what does this mean for your pet? If your pet has been found to have a heart murmur but doesn’t have signs of heart failure, it will be worth having a talk to your vet as to whether heart medication might be appropriate. They may recommend an ultrasound of the heart, chest xrays, starting medication, or just monitoring for now.
For dogs with signs of heart failure, there are a variety of medications which can help control signs of the condition. Your Vet will be able to prescribe the appropriate medication for your pet, which may involve a combination of several different drugs.
With appropriate and early treatment, we can maximise your pet’s life span and keep them happy and healthy for longer.