Understanding Heart Murmurs in Dogs and Cats

Hearing that your dog or cat has a heart murmur can be unsettling—but it doesn’t always mean something serious is going on. A heart murmur is an abnormal sound heard during a physical exam with a stethoscope. Instead of the usual “lub-dub” of a healthy heartbeat, a murmur may sound like a whooshing or swishing noise. This happens when there’s turbulent blood flow within the heart.