07/22/2025
Did you know all puppies are born with a heart murmur? After about 6-8 weeks the majority of the puppies hearts tighten up and no longer have a murmur. Some puppies it take a little longer. Just like kids, not all puppies grow and develop at the same rate. Give them a bit of time and their hearts tighten up and puppy scampers into adulthood.
Puppy murmurs are different from adult murmurs because of philology. Puppies hearts are normal and are just tightening up the heart just as the bones are firming up. Murmurs range from no murmur to 1/6 - a vet described it to me as “you hear something you think, but your not really sure it’s there.” A 2/6 you can hear it a bit more clearly. The simple puppy murmurs stay in the 1-6 to 2/6 range and generally clear up by 3-6 months of age. Another vet told me a “thud” sound is good, if you have a “swish” sound, that isn’t a normal sound - that can indicate heart valves. If that is heard the doctor will make note of what they heard. The murmur score goes to up to 6/6.
Did you know a dog can have no murmur and develop a 1/6 murmur in pregnancy and nursing then go back to normal afterwards? My vet laughter and said,” Not just dogs, people too! I was one of them. I had a murmur with each of my pregnancies and afterwards didn’t. It’s quite common.”
So what does a 1/6 murmur puppy / dog act like? Exactly the same as all other dogs. They run, play, all the same. A 2/6 potentially wouldn’t run quite a long or quite as hard for the same duration, but other than that is exactly the same as all the rest. They grow fine, play, are healthy. (Even dogs in adulthood with 1/6 and 2/6 murmurs lead normal lives.)
A vet will always tell you, “I am not a cardiologist. They can run tests, I just listen. The far majority of murmurs clear up but there some that don’t and could worsen. I can not guarantee the type of murmur I hear”. But if they were to hear an abnormal sound they will tell you and make note of that.
If you plan to get a puppy, read up on puppy murmurs. Most breeders will have in their contracts that “1/6 or 2/6 puppy murmurs are considered a normal finding and not an abnormal finding” and are considered normal
Within their health guarantees.