Pet Insurance for Heart Murmur 2026: Coverage, Cost & the Pre-Existing Catch

Last updated: September 2, 2026 | Expert reviewed

"There's a slight murmur, probably nothing, let's keep an eye on it" is one of the most common sentences a vet says at a puppy or senior wellness exam — and one of the most consequential for pet insurance, because it can be written into a medical record months or years before an owner ever thinks about buying a policy. A murmur by itself isn't a heart condition; it's a sound that tells a vet something is worth investigating further. But for insurance purposes, that sound alone can be enough to trigger a permanent exclusion if it predates enrollment. This guide explains what a heart murmur actually is, which pets are most at risk, how the pre-existing rule treats it, what a real workup costs, and how to time enrollment so a routine finding doesn't become an expensive gap in coverage.

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What Is a Heart Murmur, Exactly?

A heart murmur is an extra "whooshing" sound a vet hears through a stethoscope during the normal heartbeat — it is a physical exam finding, not a disease. Per Cornell's Riney Canine Health Center, murmurs are graded on the Levine scale from I to VI: a Grade I murmur is barely audible even in a quiet room, Grade III is heard immediately on auscultation, Grade V has a palpable vibration (a "thrill") through the chest wall, and Grade VI can be heard with the stethoscope lifted slightly off the chest. Crucially, Cornell notes that the grade of a murmur does not reliably predict the severity of the underlying disease — a loud murmur can come from a mild finding and a soft one can mask something more serious. The only way to know what's actually causing a murmur is an echocardiogram (a cardiac ultrasound), which is why "murmur" and "heart disease" are not interchangeable terms even though owners often use them that way.

Congenital vs. Acquired: Two Very Different Risk Stories

Where a murmur comes from — and what it means for a pet insurance policy — depends heavily on whether it's congenital (present from birth) or acquired (develops with age).

Congenital Murmurs: A Puppy Exam Finding

Subvalvular aortic stenosis (SAS), a narrowing below the aortic valve, is the second most common congenital heart defect in dogs, accounting for roughly 25–31% of congenital cases, per Cornell's Riney Canine Health Center. Cornell confirms it disproportionately affects Boxers, Golden Retrievers, Rottweilers, Newfoundlands, Bullmastiffs, and German Shepherds, with Boxers carrying a 9.4-times higher odds ratio of the condition than the general dog population; a genetic basis has also been confirmed specifically in Newfoundlands. A murmur picked up at a puppy's first or second wellness visit, in one of these breeds especially, is worth taking seriously rather than assuming it's incidental.

Acquired Murmurs: An Aging-Dog Story

Myxomatous mitral valve disease (MMVD) — a degeneration of the heart's mitral valve — is the most common acquired heart disease in dogs, estimated to account for roughly three-quarters of all canine heart disease diagnosed. It disproportionately affects small breeds: Cavalier King Charles Spaniels are the textbook example, with published research finding roughly half affected by age 6–7 and rates approaching universal by age 10–11 in some study populations — see our Cavalier-specific coverage guide for the full breed breakdown. More broadly, MMVD is understood to affect more than half of small-breed dogs over age 8, making an acquired murmur at a senior wellness exam a routine, expected finding rather than a rare one.

Is a Heart Murmur a Pre-Existing Condition for Pet Insurance?

Almost always, if it was noted before your policy started or during the waiting period. Most major insurers define a pre-existing condition broadly — as any sign, symptom, or abnormality a vet or owner noticed before coverage began, not only a confirmed diagnosis. That broad wording is the trap: an unconfirmed, low-grade murmur written into a chart as "monitor, recheck in 6 months" can still meet the definition, even though no vet ever said the word "disease." Once that note exists before enrollment, cardiac care is typically excluded going forward — and because conditions like SAS and MMVD are progressive and not curable, there is generally no symptom-free window that resets the exclusion the way there can be for a one-off, fully-resolved issue.

What varies by insurer and policy wording is the scope of that exclusion — whether it covers only the specific finding noted, or the entire cardiac disease category that develops later. That distinction is significant enough, and inconsistent enough across providers, that it's worth confirming directly with an insurer before enrolling a pet with any murmur history, rather than assuming every company draws the line the same way.

What's Typically Covered vs. Usually Excluded

Covered (If Diagnosed After Enrollment)

• Cardiology consult and workup — physical exam, chest X-rays, bloodwork tied to the new finding
• Echocardiogram to identify the specific underlying cause
• Ongoing monitoring for a diagnosed condition, including recheck echoes
• Medication such as pimobendan once a condition like MMVD is confirmed and treatment starts
• Emergency care for complications like congestive heart failure, if the underlying condition wasn't pre-existing

Usually Excluded

• Any murmur or cardiac finding noted before your policy started or during the waiting period — the central issue this guide covers
• Care during the waiting period itself (commonly 14–15 days for illness, though it varies by insurer and state)
• Routine wellness auscultation as part of an annual exam, unless a wellness add-on is included
• Breeding-related cardiac screening some breeders request before a puppy is placed, which typically predates any policy entirely

What a Heart Murmur Workup and Treatment Actually Cost

Once MMVD is confirmed, staging matters for both prognosis and treatment timing. Under the ACVIM's consensus staging system, Stage B1 means the valve is degenerating but the heart hasn't remodeled yet, so treatment usually waits. Stage B2 means measurable heart enlargement is present — even with no outward symptoms — and current guidance recommends starting pimobendan at B2 rather than waiting for symptoms, since it has been shown to delay the onset of congestive heart failure by roughly 15 months on average. That staging distinction is exactly why an insured pet's periodic recheck echoes matter: catching the B1-to-B2 transition early is what makes the earlier medication timing possible.

How Common Is an Incidental Heart Murmur?

More common than most owners expect. One study found a murmur in 23% of dogs presented as apparently healthy at a routine exam, and of the murmurs identified, roughly 6–12% turned out to be purely physiological — meaning benign blood-flow noise with no underlying structural heart disease at all, typically low-grade (I–III) and heard only during systole. The remaining majority still require a cardiology workup to sort out which specific condition, if any, is causing the sound, since grade and sound character alone can't make that determination. Congenital heart disease overall is estimated to affect roughly 4.6 to 8.5 per 1,000 dogs in the general population — uncommon, but common enough that a first-visit murmur in a young puppy of an at-risk breed shouldn't be dismissed without a look.

Best Pet Insurance If Your Pet Has Cardiac Risk

No insurer specializes in murmurs specifically — the deciding factor here is almost entirely enrollment timing rather than which company you choose. The four below each offer standard accident-and-illness cardiac coverage once a policy is active and past its waiting period.

Exact pre-existing and curable-condition wording varies by insurer, state, and plan version — confirm current terms at quote time, especially the scope of any cardiac exclusion if your pet already has a murmur on record.

How to Protect Yourself

• Enroll before the first vet visit that could reveal a murmur: for a puppy, that's often the 8-week wellness exam — insuring before that visit is the single most effective step for at-risk breeds
• Ask your vet to document clearly: if a murmur is found and judged innocent, ask that it be noted as such in the record rather than left ambiguous, since precise documentation can matter later
• Don't skip the recheck to avoid a paper trail: delaying a recommended follow-up doesn't prevent a pre-existing designation and risks missing a real diagnosis
• If your pet already has a noted murmur, still enroll: every non-cardiac condition remains fully coverable, and insurance still protects against accidents, cancer, and every other illness
• Compare curable-condition reset windows: they matter far less for a progressive condition like MMVD or SAS, but they're worth understanding before you assume any exclusion is temporary

Frequently Asked Questions

Does pet insurance cover a heart murmur?

It depends on timing. If a vet first notes a murmur after your policy's illness waiting period has passed, the diagnostic workup and any resulting treatment is covered like any other illness. If a murmur was already noted before you enrolled or during the waiting period, most insurers treat it as pre-existing and exclude cardiac care going forward, whether or not a formal diagnosis was ever made.

Is a heart murmur a pre-existing condition for pet insurance?

Usually, yes, if it was noted before enrollment. Most insurers define pre-existing broadly — any sign or symptom noticed before the policy started, not just a confirmed diagnosis. Whether the exclusion covers just that finding or the whole cardiac disease category that develops later varies by insurer, so confirm directly before enrolling a pet with a known murmur.

Can a vet always tell if a puppy's heart murmur is serious?

No. A peer-reviewed survey of 452 vets found only 9% considered it easy to reliably distinguish an innocent puppy murmur from an early sign of real heart disease using auscultation alone, even though 88% found detecting a murmur itself easy. A "probably nothing, monitor it" note reflects genuine diagnostic uncertainty, not routine caution.

What does it cost to work up a heart murmur?

A cardiology consult typically runs $150 to $450, and an echocardiogram usually costs $300 to $1,200 depending on the setting — a full workup commonly lands between $450 and $1,650. If a condition like MMVD is confirmed and pimobendan is started, brand-name medication runs $60 to $277 per month.

How common is it for a vet to find a heart murmur at a routine exam?

A murmur was found in 23% of dogs presented as apparently healthy in one study, and of those murmurs, roughly 6 to 12% were purely physiological with no structural disease at all. The rest still need a cardiology workup, since grade and sound alone can't determine the cause.

What is the best pet insurance if my pet has a heart murmur risk?

There's no single "best" insurer for murmurs specifically, since enrollment timing matters far more than which company you pick. Embrace, Healthy Paws, Spot, and ASPCA all offer standard cardiac coverage once a policy is active and past its waiting period — the real lever is enrolling before any murmur is ever noted, especially in breeds with known congenital or age-related cardiac risk.

The Bottom Line

Pet insurance for a heart murmur comes down to a single piece of timing more than almost any other condition on this site, because a murmur is often noted long before it's understood — sometimes years before it develops into anything, sometimes as the very first sign of a serious congenital or acquired condition. The uncertainty vets themselves report in telling those two situations apart is exactly why "wait and see" is the wrong approach to insurance shopping: a policy bought before any murmur is on record covers whatever that murmur eventually turns out to be, and a policy bought after covers everything except it.

If your puppy or senior pet hasn't had a murmur noted yet, especially in an at-risk breed, enroll now rather than after the next wellness exam. If a murmur is already on the record, insurance still won't cover that specific finding, but it fully protects every other risk your pet faces. See our guides to pre-existing conditions, chronic condition coverage, and pet insurance for Cavalier King Charles Spaniels.