Pet Vet: Dog’s heart murmur doesn’t necessarily mean heart disease

December 19, 2016

I received a letter from Andrea concerning her 1-year-old Rottweiler named Roxanne. It seems Roxanne has a heart murmur and Andrea wants to have her spayed. She has been cautioned that Roxanne, because of her heart condition, may not be able to handle an anesthetic procedure and Andrea is concerned.

In discussing this case, I think it is important to try to explain what the words heart murmur mean and what might be the consequences, if any, for a companion living with this condition.

First of all, what is a heart murmur? A heart murmur is a sound made within the heart due to abnormally turbulent blood flow. This noise is sort of a "whoosh" sound and most commonly occurs due to a leak in one or more of the heart valves. There are other possible causes for this sound made by this turbulent blood flow but for our discussion here, heart valve leakage will suffice.

Veterinarians listen to your companion’s heart with a stethoscope to hear the heartbeat and any abnormalities involving the blood flow through the heart.

Blood flows through the heart from one chamber to the next through one way "flapper" valves. There are four chambers and six valves. A leak in any one of these valves can cause a murmur because the blood, instead of flowing in the forward direction through the valve, flows backward, creating turbulence and thus an audible murmur. A leaking valve can be a congenital condition, meaning it’s been present since birth or it may develop later in life. In Roxanne’s case, I suspect a congenital heart murmur since she is only 1 year old.

The mere presence of a murmur does not imply there is heart disease. Many companions — and humans for that matter — are living totally normal lives with heart murmurs of no consequence. This is not to say that a heart murmur can not be indicative of a potential problem. The key is to determine if the detected murmur is causing a problem.

As I’m sure you’ve guessed, this is the time when a visit to your veterinarian is appropriate. In Roxanne’s case, a thorough evaluation of her heart is in order. This should include a set of chest radiographs, an electrocardiogram (that’s the electrical tracing of the heart’s activity), an echocardiogram (ultrasounding the heart), blood pressure measurement and possibly some bloodwork. With these diagnostic steps, it is possible to determine Roxanne’s heart condition and if it is now or is likely to become a problem. It can also help assess the risk from her anesthetic procedure.

The presence of a heart murmur in no way implies heart disease. With a proper workup, it is possible to determine if there is indeed a heart problem or simply a harmless murmur.




Associated Press