Heart Murmer

Question
We bred EBD's and obviously love them.  We have a 2 year old in our home and recently one of our daughters dogs had a litter but one of the puppies was very small and was being pushed off nursing so we decided to take him home.  His was about half the size as the rest and after taking him to the vet we discovered he had a heart murmer.  If he was to die with it we decided to care for him until then. Well, he hasn't died and of course he is spoiled rotten.  He has grown to the same height as his sibling but isn't as heavy as his brother.  My question is as he plays with the older dog he does pant a little more then she does but seems to do well otherwise.  What problems can we expect of her.  The vet has told us he might grow out of it to some extent. He is about 5 months old.

Answer
You're better off to let him exercise on his own, just monitor him so he doesn't get exhausted. These types of murmurs are often referred to as "musical murmurs" because they sound like a whistle. It's caused by a heart valve that isn't fully closed usually due to not being fully developed. Often these resolve on their own by the time the puppy is 3 months old.  If you're still hearing this at 5 months, chances are it will always be there.  There's no reason to think this would affect him at all if it's slight.

I have a 2 wk old litter here now. The largest is 2.6 lbs. and the runt is 12 ozs. He refuses to die and I just know I'll end up keeping him forever.