Heart Murmur

Cavalier King Charles Spaniels

Toy Poodles

Mitral Valve Disease (MVD)

Cavalier King Charles Spaniels

A heart murmur is an abnormal heart sound that is heard when listening to the heart with a stethoscope. It is caused by an abnormal turbulent blood flow. It can also occur when blood flows very fast when your puppy is excited or scared.


Your vet will grade the heart murmur out of 6, with 6/6 being the loudest. An ultrasound is a non-invasive test that is performed to determine the cause of the murmur.


If you have a new puppy

Soft heart murmurs (grade 1 to 3/6) can occur in young puppies and are of no consequence to them. These types of murmurs are called “innocent” murmurs, they usually go away by 14 weeks of age.


Loud heart murmurs (Grade 4/6 to 6/6) in a new puppy should be assessed by a cardiologist. This may indicate that congenital heart disease is present.   The cardiologist will perform an echocardiogram as well as other tests to assess the heart and determine if heart disease is present.

Depending on the disease present, some congenital diseases can be fixed or made better with an interventional catheter procedure.

Mitral Valve Disease

Approximately 10% of dogs develop heart disease during their lifetime, approximately 80% of the heart disease will be due to the mitral valve,  mitral valve problems are more common in small dogs than large dogs and generally affects older dogs.

2022: Here at CameronCavs our Cavaliers are tested in association with the Veterinary Cardiovascular Society and in agreement with the RCVS before they are allowed to breed.  In 2019 new scheme assessment tests came in for Cavalier King Charles Spaniels and now it is recommended that they are tested at ages 2, 4, 6 & 8 by a recognised canine cardiologist.