My Wylie has had a heart murmur for years now, and takes Enalapril. The vet can barely even hear the murmur with the meds doing their work. Dogs can do *amazingly* well w/ murmurs and early-CHF, so just be assured that it doesn't necessarily mean really bad news, or even close
.
It can get worse, or stay the same forever - no predicting this.
If the murmur IS putting add'l strain on some part of the heart - then - I would ask for a cardiac med that mitigates this.