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Heart Murmurs in Australian Shepherds: A Sound, Not a Verdict

Quick answer

Is a heart murmur a diagnosis?

No — it's a finding that prompts further testing, usually an echocardiogram, to determine an actual cause.

A murmur is the sound of blood moving turbulently through the heart — it tells your vet something is worth a closer look, but it doesn't say what that something is on its own.

Heart Murmurs in Australian Shepherds: A Sound, Not a Verdict infographic

Owners who just got a call or a note after a routine exam saying their Aussie 'has a murmur' and aren't sure whether that means a minor detail or something to worry about.

Important reminder

This guide is not medical advice. If your dog shows pain, sudden behavior change, or worsening symptoms, consult a licensed veterinarian.

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What this problem looks like

A heart murmur is the sound of turbulent blood flow through the heart, picked up with a stethoscope. In Australian Shepherds it's almost always found incidentally at a routine or puppy exam rather than because the dog was showing symptoms. A murmur is a signal to investigate further, not a diagnosis, and the grade alone doesn't reliably predict how serious the underlying cause is.

Common triggers

  • A routine puppy wellness exam
  • An annual adult checkup with a stethoscope listen
  • A pre-adoption or pre-purchase veterinary exam
  • A pre-anesthetic exam before a routine procedure like a spay or neuter
  • A recheck scheduled specifically to track a previously noted murmur

Murmurs are found across dogs of every breed at some point, and Australian Shepherds are no exception. There's no documented evidence this breed has an elevated rate of murmurs specifically, but because they're found incidentally, many go unnoticed until a routine exam happens to catch one.

Why this happens

Breed factors

Nothing in this breed's documented profile points to a specific murmur-causing trait. Murmurs occur across the general dog population from a range of causes, some congenital and some acquired later in life, and Aussies aren't documented as an outlier either way.

Environment factors

Environment doesn't cause a murmur, but a stressed or excited dog can sometimes have a temporarily faster heart rate that makes an existing soft murmur easier or harder to hear clearly at a given visit — which is part of why vets often recheck before drawing conclusions.

What you can do at home (once it is not an emergency)

When to talk to your vet

Any new murmur should be discussed with your vet, who will decide whether it warrants immediate referral or a wait-and-recheck approach. Seek care the same day if a murmur is accompanied by fainting, pale or bluish gums, labored breathing, or sudden weakness.

At home, alongside your vet's plan

  • Keep your dog calm for a few minutes before a wellness exam if possible, since a very excited heart rate can make listening harder.
  • Ask your vet directly for the murmur's grade and location so you have a specific baseline to compare against next time.
  • Note the date of any murmur finding so you and your vet can track whether it's new, stable, or changing over successive visits.
  • Don't restrict your dog's normal activity based on a murmur alone — wait for your vet's guidance after any imaging.
  • Bring up a murmur finding proactively before any planned anesthesia (like a dental cleaning) so it can be factored into the anesthetic plan.

More Australian Shepherd health & behavior issues

See all Australian Shepherd health problems, which breeds are prone to heart murmurs, or the full Australian Shepherd breed guide for temperament, exercise needs and ownership costs.

What to expect, and how you know it is working

From the day a murmur is found to a confirmed answer via echocardiogram usually takes a few days to a few weeks, depending on referral availability. Innocent murmurs in puppies are often reassessed over a few months before being called resolved.

Success looks like moving from an unclear sound finding to a specific answer — whether that's 'nothing structurally significant' or a named condition with its own monitoring plan — rather than staying in an uncertain holding pattern.

How murmurs get graded, and why the number isn't the whole story

Vets grade murmurs on a scale from 1 to 6 based on how loud and easily audible the sound is — a grade 1 is very soft and only heard in a quiet room with careful listening, while a grade 6 is loud enough to feel as a vibration through the chest wall. It's tempting to treat the grade as a severity score, but it isn't a reliable one on its own. A loud murmur can come from a relatively minor issue, and a soft one can occasionally point to something more significant. The grade tells your vet how to describe what they heard; it doesn't replace imaging.

What the grade is genuinely useful for is tracking change over time. A murmur that goes from a grade 2 to a grade 4 between visits is a meaningful trend worth investigating, even if a grade 4 in isolation wouldn't necessarily alarm anyone.

From 'we heard something' to an actual answer

Once a murmur is found, the next step is usually a referral for an echocardiogram — an ultrasound of the heart that shows the actual structures and how blood is moving through them. This is the test that turns 'there's a sound' into an actual answer: a specific valve leaking, a narrowed vessel, or sometimes nothing structurally meaningful at all (an 'innocent' murmur, more common in puppies, that many outgrow by adulthood).

Until that workup happens, the honest answer to 'what does my dog's murmur mean' is genuinely 'we don't know yet.' That's an uncomfortable place to sit, but it's the accurate one, and rushing to assume either the best or worst case before the imaging is done doesn't serve the dog.

Heart Murmurs in Australian Shepherds: A Sound, Not a Verdict - From 'we heard something' to an actual answer
Heart Murmurs in Australian Shepherds: A Sound, Not a Verdict - From 'we heard something' to an actual answer

The Murmur That Followed a Puppy Through Its First Year

At Bandit's eight-week puppy exam, the vet noted a soft, grade 2 murmur and flagged it for a recheck rather than immediate concern. At four months, it was still there, roughly the same. Bandit's family kept every appointment, and by his one-year exam, the murmur had quietly disappeared — the vet's best explanation was that it had been an innocent puppy murmur that resolved as his heart finished developing. Nothing about Bandit's daily life changed during that year; he ran, played, and grew normally the whole time. The only difference was a series of calm, unremarkable stethoscope checks that eventually confirmed there was nothing to chase further.

Key takeaway: Not every murmur needs an immediate echocardiogram — sometimes the right next step is simply patient, consistent rechecking, and that's a legitimate medical plan, not a delay in care.

Frequently asked questions

My Aussie puppy has a soft murmur — should I be worried?

Not necessarily. Soft murmurs found in puppies are sometimes 'innocent' and resolve on their own by adulthood. Your vet will likely recheck it at the next visit or two to see if it's changing before recommending an echocardiogram.

How is a murmur actually found?

Almost always by a vet listening with a stethoscope during a routine physical exam, not because the dog is showing any symptoms at home. That's why regular wellness visits matter even for dogs that seem perfectly healthy.

Does the murmur grade tell me how serious it is?

Not reliably on its own. The grade describes loudness, which doesn't always match up with structural severity. It's more useful for tracking whether a murmur is changing over time than for judging severity at a single visit.

What test actually tells you what's causing a murmur?

An echocardiogram — an ultrasound that lets a cardiologist see the heart's valves, chambers, and blood flow directly, rather than just hearing a sound through a stethoscope.

Can a murmur go away on its own?

Some can, particularly mild murmurs found in young puppies that turn out to be innocent rather than tied to a structural issue. Murmurs found later in life are less likely to simply resolve and are more often worth a full workup.

Should my Aussie avoid exercise if it has a murmur?

Not automatically — activity restrictions should come from your vet after imaging clarifies what's actually going on, not from the murmur finding by itself.

How often will my dog need rechecks if a murmur is found?

This depends entirely on what the echocardiogram shows. A confirmed innocent murmur may need just a follow-up or two; a structural finding usually comes with its own specific monitoring schedule from a cardiologist.

Quick answers

View more answers
Health

Is a heart murmur a diagnosis?

No — it's a finding that prompts further testing, usually an echocardiogram, to determine an actual cause.

Health

How are murmurs graded?

On a scale from 1 (very soft) to 6 (loud enough to feel through the chest), though the grade doesn't reliably predict severity by itself.

Health

Can puppy murmurs disappear on their own?

Some do — mild murmurs found in young puppies are sometimes innocent and resolve by adulthood without ever being tied to a structural problem.

Health

What test actually explains a murmur's cause?

An echocardiogram, which lets a cardiologist see the heart's actual structures rather than just hear a sound.

Behavior

Should I panic if my vet mentions a murmur?

No — most murmurs are found incidentally at routine exams, and many turn out to be minor or unimportant once properly evaluated.

Related DogBreedCompass guides

  • congenital heart defects in Australian Shepherds – Readers whose murmur turned out to be congenital want the specific defect explained.
  • Australian Shepherd heart conditions overview – A broader map helps place a murmur finding in the context of other cardiac terms.
  • mitral valve disease in Australian Shepherds – Valve disease is one of the more common structural causes behind an adult-onset murmur.
  • Australian Shepherd puppy health screening – Owners preparing for a puppy exam often want to know what other conditions get screened for early.
  • Australian Shepherd vet cost breakdown – A cardiology referral adds an unplanned cost many owners want to budget for.

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