Heart murmurs in puppies

I was with a service dog client and her puppy for their very first vet visit. That little Labrador retriever puppy was 10 weeks old. The physical exam went smoothly. After listening to the puppy's heart, the vet said - almost in passing - that the puppy had a heart murmur. You could have heard a pin drop in that room. 

Since that experience, I have learned that juvenile heart murmurs are not unusual in puppies. I asked my vet to describe them for me, so I could share the information with you. Here is what she said:

"Basically a heart murmur is a turbulent or abnormal blood flow.  We use a scale of 1 to 6 to "grade" them based on severity.   Most puppy murmurs we run into fall into the juvenile or "innocent" murmur category.  These are soft (grade 1 or 2) murmurs that 90% of puppies will grow out of by the time they are 6 months old.  The louder, more severe murmurs (3 to 6) are more concerning in puppies as they may indicate something more severe (septal defects - hole in the heart wall, etc.)." 

I hope you never hear the words "heart murmur" associated with your own puppy. If you do, know that the odds are good that it is an issue that will resolve itself, as it did with the puppy I described above.