Hearing that your pet has a heart murmur can be unsettling. Some pet owners are told, “It’s common” or “It can happen with age”—but it’s important to understand the truth: heart murmurs are not normal, and they should never be ignored.

What Exactly Is a Heart Murmur?

A heart murmur is an abnormal sound heard during a heartbeat, usually detected by a veterinarian using a stethoscope. Instead of a smooth “lub-dub” rhythm, the blood flow creates a whooshing or swishing noise.

This typically indicates turbulent blood flow, which can be caused by underlying heart issues.

Are All Murmurs Serious?

Not all murmurs mean severe disease—but all murmurs warrant attention.

They are graded on a scale (usually 1–6) based on how loud they are, but the grade doesn’t always correlate perfectly with severity. Even a quiet murmur could signal severe disease.

Possible causes include:

  • Valve disease (like mitral valve disease)
  • Congenital heart defects
  • Cardiomyopathy
  • Anemia or other systemic conditions

Why Early Monitoring Matters

One of the biggest risks with heart murmurs is assuming they’re harmless. In many cases, murmurs are the first detectable sign of heart disease, appearing before symptoms develop.

Early monitoring allows veterinarians to:

  • Track progression over time
  • Begin treatment at the right stage
  • Prevent or delay heart failure

What Happens After a Murmur Is Detected?

Your veterinarian may recommend additional diagnostics, such as:

  • Echocardiogram (heart ultrasound)
  • Chest X-rays
  • Blood pressure checks
  • Routine rechecks to monitor changes

These tests help determine whether the murmur is benign or linked to a more serious condition.

Signs to Watch at Home

Even if your pet seems fine, watch for:

  • Coughing
  • Decreased energy
  • Rapid or labored breathing
  • Fainting or weakness

If any of these develop, prompt veterinary care is essential.

A heart murmur is not just a “normal part of aging.” It’s a signal—one that deserves attention, monitoring, and sometimes treatment. Staying proactive can make a significant difference in your pet’s health and longevity.