How Serious Is a Heart Murmur in Dogs?

Does something about your dog’s heartbeat sound off? Heart murmurs in dogs aren’t unusual. In fact, over a quarter of all puppies have signs of a heart murmur.¹ But what causes this condition, and is it something to worry about? Keep reading to learn the ins and outs of dog heart murmurs.

What Is a Heart Murmur in Dogs?

Heart murmurs can be defined simply as an irregular heartbeat.² Usually, a vet would notice and diagnose a heart murmur while listening to your dog’s heart with a stethoscope during a routine examination. You may also be able to hear the heart murmur yourself by listening to your dog’s chest.²

What Causes Dogs to Get Heart Murmurs?

The irregular beat of a heart murmur is generally caused by uneven or turbulent blood flow through a dog’s heart. The root cause of this turbulence could be anything from a slightly leaky heart valve to a more serious underlying infection.² Since there’s such a vast range of causes of heart murmurs in dogs, they are divided into two categories: “innocent” and “pathologic.”²

Typically, innocent heart murmurs won’t have a negative impact on a dog’s overall health. The most common type of innocent heart murmur occurs in puppies and is caused by the rapid growth of their hearts during the first few months of their lives.²

A pathologic dog heart murmur is either caused by a structural issue with a dog’s heart or by other extracardiac factors.² Structural issues could include birth defects or heart disease. Potential extracardiac problems can include:^1,2

• Anemia
• Hyperthyroidism
• Bacterial infection
• Obesity

Is a Dog Heart Murmur Serious?

Innocent heart murmurs in dogs may not require any additional treatment and could simply go away on their own — as is the case with many young puppies.² However, a pathologic dog heart murmur caused by a structural defect or disease could develop into a serious condition if it isn’t treated.²

Dog Heart Murmur Symptoms

The main symptom of a dog heart murmur is the murmur itself. Your vet will listen with a stethoscope for any irregularity in your pup’s heartbeat.

Based on how loud the heart murmur is, it will be given a grade on a scale of I to VI.² Grade VI heart murmurs are loud enough to be heard and can be felt wherever that dog’s heartbeat may be heard and felt; conversely, Grade I heart murmurs are quiet and might only be heard occasionally and/or when a hand is placed over the dog’s heart.²

If your vet is concerned about a heart murmur, they may recommend additional tests to determine the root cause. Heart murmurs that are caused by disease or an extracardiac factor will usually have other clinical signs the vet can look for, potentially including:²

• Exercise intolerance
• Low appetite
• Pale gums
• Breathing issues
• Coughing
• Fainting

Your vet might also recommend an X-ray, ultrasound, or electrocardiogram (ECG) to directly image your pup’s heart and surrounding structures. ECGs in particular can be used to observe the flow of blood into and out of your dog’s heart, which in turn can help your vet see the turbulence causing the murmur.²

When should I worry about a heart murmur in my dog?

If you begin to observe the symptoms listed above, they could indicate a dangerous heart murmur. You should seek medical attention for your pup as soon as you suspect something is wrong.

Treatment for Heart Murmur

Once a cause has been identified, your vet will likely discuss next steps in the form of treatment options. This could involve a specialized diet and prescription medication, or it could mean simply monitoring your dog’s heart health as they continue to grow and age. Murmurs caused by defects might need corrective surgery.²

That brings us to the question on the mind of every pet parent whose pup has a heart murmur:

How long can a dog live with a heart murmur?

If your dog has an innocent heart murmur, they may live a long and happy life unaffected by their irregular heartbeat. Pathologic heart murmurs don’t necessarily indicate a shorter lifespan with the proper treatment. Even if the murmur is caused by heart disease, it’s possible the issue could be corrected with surgery.²

Can Dog Insurance Help With Heart Murmurs?

Heart murmurs in dogs can be innocent, but the same can’t be said for the cost. The cost of a single exam could run you $40 – $85, plus blood work could tack on $50 – $350.³ Your vet might also refer you to a cardiologist, which could add another $400 – $1,000 to your bill.³ When you add the potential cost of medication (up to $150), even the most innocent of heart murmurs can begin to add up to a hefty vet bill.³

Fortunately, a dog insurance policy could help cover many of the costs associated with dog heart murmurs. For a real-life example of MetLife Pet customers who saved on heart murmur costs, look at Mocha the Washington-based pup. This senior dog developed a heart murmur at the age of 11, and the subsequent examinations cost over $1,800. MetLife Pet reimbursed Mocha’s parents for nearly $1,500 — over 80% of their bill!⁴

When it comes to your pup’s health, it’s good to get a head start. Begin your journey with a free quote today. Or learn more about how our pet insurance works to help protect your pet and your wallet!