Our Library of Dog Health ArticlesHeart Murmurs
A heart murmur is a specific sound detected when listening to the heart with a stethoscope. This sound is a result of the blood flowing faster than normal within the heart itself or in one of the two major arteries leaving the heart (the aorta and pulmonary artery). Instead of the normal Lubb Dupp, an additional sound is present that can vary from a mild pshhh to a loud whoosh!
Your vet will use a grading system from 1 to 6 to describe how loud the murmur is e.g. a grade 1 murmur is very soft and a grade 6 murmur is very loud. You should ask your Vet for this assessment.
Heart murmurs in puppies
If a heart murmur is present from birth or develops shortly after birth, it will probably be noticed by your veterinary surgeon at the time of vaccinations. The most common type is called an innocent“flow murmur”. This type of murmur is soft (typically a grade 2 or softer) and is not caused by underlying heart disease and will generally disappear in the first year.
However if a puppy has a loud murmur (grade 3 or louder), or if the heart murmur is still easily heard with a stethoscope after 4-
Heart murmurs in adult dogs
This type of heart murmur is usually due to heart disease that develops with age and was not present when a puppy.
In toy and small breeds of dog, a heart murmur may develop due to thickening and degeneration of the mitral valve in the heart, preventing it from closing properly and consequently leaking. The heart then has to work harder to compensate for this pumping inefficiency
The heart muscle has enlarged and can distort the mitral valve so that it cannot close properly. The resultant leak across the valve will cause a heart murmur.
How is a heart murmur treated?
If the heart murmur is caused by an underlying problem, the treatment will be based on the diagnosis, and may include a combination of specialized diets, medications and supportive care. Only a few congenital heart defects can be surgically corrected. Treatment and Care may well be required throughout your pet’s life.
Factors outside of the heart can cause murmurs
Not all murmurs are the result of a problem in the heart. Blood disorders, obesity, emaciation and parasitic conditions can create the conditions necessary to initiate a heart murmur.
What is the outlook?
The prognosis ranges depending on the cause of the murmur. If the murmur is not strong and the dog is a puppy the your vet will probably just keep and eye on the situation and offer no treatment.
The outlook for a dog with dilated cardiomyopathy varies –