Hi Have no experience but found this article. Depending on the age of your puppy they might outgrow it. What has the vet said? https://vcahospitals.com/know-your-pet/heart-murmurs-in-dogs
May outgrow it IF it is an “innocent” murmur. I would HIGHLY recommend scheduling a echocardiogram with ur vet to rule out pathologic reasons i.e PDA etc.