Heart Murmur in Dogs: Guide for Pet Owners

A medical condition may be diagnosed anytime during your pet’s lifetime, even at birth. Some illnesses are known while others may prompt more questions. Because of this, it is important to be mindful of medical conditions that can affect dogs of all ages, such as heart murmurs.

If you're concerned about your dog's heart health, it's important to make an appointment with their veterinarian as soon as possible. Many heart conditions are treatable, but early prevention is key. Heart murmurs are no exception to this.

What is a canine heart murmur?

A heart diagnosis can be concerning, but what does it actually mean for your pet?

“A heart murmur indicates the turbulent flow of blood in the heart," explains Trupanion veterinarian Dr. Sarah Nold. "If it’s severe enough, it can not only be heard but also felt when you lay your hand over your dog’s heart.”

If you are concerned about your dog, please seek the medical expertise of your veterinarian. They can listen to your dog’s heart and recommend the best course of action for your best friend.

How dogs get heart murmurs

Heart murmurs can start at any time during your dog’s development. You might associate a heart condition with only adult or senior dogs, but that’s not always the case.

“Dogs may be born with heart murmurs, or they can develop them when they get older. Heart murmurs can have many causes, including defects in the heart wall to thickening of the heart valves," Nold says. "Your veterinarian can get more information about the possible causes of a heart murmur by listening with a stethoscope while taking into account the age and breed of the dog. However, often diagnostics and possibly a referral to a veterinary cardiologist are necessary to get a specific diagnosis.”

Although your dog may receive a heart murmur diagnosis, it does not always mean there is only one treatment plan. Every dog is different, and there are different levels of heart murmur diagnosis ranging from daily medication to surgery.

Signs of a heart murmur in dogs

While a heart murmur might sound daunting, your dog might not even look or act sick. That is one of the mysterious things about heart murmurs in dogs. It’s really dependent on the level of severity of the murmur for your dog.

According to Nold, the following signs that may be related to the cause of your murmur:

• Anemia
• Hyperthyroidism
• Heartworm disease
• Labored breathing
• Collapsing
• Valvular heart disease

“With heartworm disease, you may see signs such as coughing and exercise intolerance. But most often, there are no signs until your veterinarian listens to your pet’s heart,” Nold adds. "For this reason, yearly wellness exams and check-ups with your veterinarian are so important. Early detection is key."

How serious are dog heart murmurs?

Not all heart murmurs are the same for every dog. While some heart murmurs are a grade one, which is barely audible, a grade four is pronounced and loud. Your veterinarian will be able to determine the grade of the heart murmur and get more information from the cardiologist from an echocardiogram.

Pet insurance claims data

Trupanion, one of the leading pet health insurance providers, paid out $5,858,000 for dog heart murmur claims in 2023 alone. Averages paid out to individual pet owners for singular canine heart murmur claims fell between $200 and $500, with some outliers for more severe or milder cases.

The following dog breeds tend to claim most frequently for heart murmurs:

• Japanese Chin - over 10 times more likely to claim than the average dog
• Cavalier King Charles Spaniel - 8 times more likely to claim than the average dog
• Whippet - 5 times more likely to claim than the average dog
• Brussels Griffon - 3.8 times more likely to claim than the average dog
• Chihuahua - 3.8 times more likely to claim than the average dog

Real dog heart murmur story

“Spencer was diagnosed with a heart murmur in 2018. With the help of a Trupanion policy we’re able to give her the medical care that she needs. It’s stressful emotionally and financially when you have a sick pet. Because of Trupanion, the financial stress is taken away. We don’t have to make decisions based off finances. We can make decisions based on getting the best care possible for Spencer. Between cardiology appointments and monthly medication, the Trupanion policy has paid $4,039.52 in claims for her heart murmur. We’re so grateful.”

-Kelli, a Trupanion member since 2016

Treatment options

Treatment will be dependent on the severity of your dog’s heart murmur. For instance, “some heart murmurs only need to be monitored, and in some cases, like in young puppies, they go away with time. Treatment depends on the underlying cause of the heart murmur, which in rare cases may involve surgery. Further, most treatment involves close monitoring until medication becomes necessary,” states Nold.

What to expect with your pet

If your dog gets a heart murmur diagnosis, remember every dog’s treatment plan is different. Not every dog will need medication or surgery. Fortunately, with the advancements in veterinary medicine and the help of your veterinarian, your dog can receive the best care possible. And plenty of cuddles and positivity from the family certainly helps!