Puppy heart murmurs – when should I worry?

One of the common questions vets are faced with is when to worry about puppy heart murmurs. We all dread the excited owner who brings their gorgeous new puppy in for a check, only to find he or she has a heart murmur. We need to be sure to give the best advice on what to do next.

Innocent heart murmurs are common in puppies (where there is no structural heart disease and no physiologic reason for the murmur such as anaemia or hypoproteinaemia). These murmurs will commonly disappear by 4-6 months of age. However unfortunately there are also a range of congenital heart defects which can lead to reduced quality of life, or heart failure and premature death. The recent “puppy boom” has led to a sudden increase in problems such as patent ductus arteriosus (PDA) and pulmonic stenosis, especially with the current popularity of breeds such as French bulldogs and Cockerpoos who are predisposed to these conditions.

As a general rule if a heart murmur is quiet (grade 1-2/6), localised, short (does not persist all the way through systole) or variable (varies or disappears at different heart rates) then it is less likely to be associated with structural defect, BUT we simply cannot be sure. A murmur only tells us there is turbulent flow in the heart, it is not a diagnostic test. So if the murmur persists, then a definitive diagnosis is vitally important and this can only be done with a full Doppler echocardiogram (cardiac ultrasound scan).

All of our cardiologists use high quality cardiac ultrasound machines, and are trained to perform a full echocardiogram to specialist standard. We  perform a full consultation and clinical examination, and will report the results of the scan immediately afterwards to the owner with a thorough discussion. We ensure they are fully informed and understand any possible treatment options or future risks for their pet. In some cases such as PDA or pulmonic stenosis, we can perform keyhole cardiac surgery to permanently fix the problem, or significantly improve it so that the puppy may lead a normal life, but it is very important to catch these early for the best outcome.

You can download an information sheet for your owners on puppy heart murmurs from the link below:

information regarding our interventional surgery programme is also available from our website here:

If in doubt don’t delay, call HeartVets today! We can arrange a convenient appointment for your client and their pet locally through our network of regional clinics.