Heart Murmur in Dogs

What Is a Heart Murmur in Dogs?

A heart murmur is an extra heart vibration that is produced as a result of a disturbance in the blood flow—enough to produce an audible whooshing sound. But before we tackle murmurs, let us first talk about how a dog’s normal heart sounds are produced.

Hear Murmur Sounds

Normal heart sounds are produced by the closure of heart valves. This closure of the two top valves produces the first heart sound (“S1” or the “lub” sound). Meanwhile, the closure of the two bottom valves produces the second heart sound (“S2” or the “dub” sound). A heart murmur is an abnormal sound that happens during blood flow. It’s a “swooshing” sound that happens between the normal “lub-dub” sounds. If you try to listen to a dog’s heartbeat using a stethoscope, a dog with a heart murmur will sound “lub-whoosh-dub”. The swooshing sound indicates a heart murmur.

Is a Dog Heart Murmur Dangerous?

According to Oakland Veterinary, a heart murmur in dogs is not considered a disease or an implication that there’s something wrong with your dog’s heart. But this serves as a red flag that there could be an issue. So, some heart murmurs can be dangerous while others are not. Some murmurs are natural or physiologic which are not dangerous and do not have any bearing on your dog’s overall health. They often happen in puppies and young dogs but they will eventually outgrow these murmurs by the time they reach 5 months old or so.

If your pup has an innocent heart murmur in puppies diagnosed by your vet, your vet will most likely recommend keeping track of your furbaby’s heart as they get a little bit older. A cardiac workup will then be warranted if the murmur can still be heard. Most murmurs however are caused by a cardiac disease or by an underlying medical condition outside the heart, which needs to be diagnosed in the soonest time possible.

What Causes Heart Murmurs in Dogs?

To better understand what causes a heart murmur, let’s have a quick glance at the anatomy of your furbaby’s heart.

As stated by VCA Animal Hospitals, your dog’s heart has four chambers. The two upper chambers are called atria, which are the right and left atrium. The two lower chambers are called ventricles (right and left). The heart also has four valves, namely the tricuspid valve, pulmonary valve, mitral valve, and aortic valve. These valves basically act as gates to allow the ventricles fill and prevent the blood from flowing backward. There is obviously a lot more to heart anatomy, but those are what we really need to know for murmurs.

A heart murmur is commonly caused by a valve problem. A leaky valve allows the blood to flow back through it when it is closed. While a stiff valve does not open up properly needing the blood to squeeze through it. Both of these circumstances cause a whooshing sound which is what we call now a heart murmur.

What Are the Different Types of Murmurs?

There are three types of heart murmurs in dogs, namely systolic, diastolic, and continuous. This classification of murmurs is based on the timing of the murmur. Knowing what type of heart murmur your dog has can help your veterinarian figure out what is causing it, so it is important to have your dog checked by a vet. Other factors to consider when a vet listens to a heart murmur in dogs are the location—where around the chest the murmur can be heard the loudest, as well as the length and the loudness of the murmur.

Heart murmur in dogs is also graded by their intensity from 1 to 6, with grade 1 reported as very soft and hardly audible and grade 6 reported as very loud and can already be felt through the chest wall. The various intensities directly refer to how loud the murmurs are.

Signs and Symptoms of Heart Murmurs in Dogs

Here are some signs and symptoms you may see in your fur-baby that may come together with a heart murmur:

• Lethargy
• Exercise intolerance
• Gray or blue gums
• Distended abdomen
• Bloated appearance
• Panting
• Difficulty breathing
• Congestion
• Sudden collapse

How Are Heart Murmurs in Dogs Diagnosed?

Heart murmurs are usually detected and diagnosed through routine checkups by your vet listening to your dog’s heart using a stethoscope. Murmurs’ intensity, loudness, location, timing, and length are all taken into consideration, as well as your dog’s age, breed, and overall health. Your vet might also perform different tests such as an echocardiogram, chest X-rays, electrocardiogram, blood and urine tests to identify the underlying cause of the murmur. Once the root issue is identified, a course of treatment can be determined if needed.

How Are Heart Murmurs Treated?

When it comes to treating your dog’s heart murmur, your veterinarian will look to treat its underlying cause and the symptoms associated with it. The underlying cause needs to be identified and addressed to treat the murmur.

In order to boost every day health, you should provide your dog with a well-balanced diet, regular exercise, and a dog multivitamin. Multivitamins SoftSupps® contain Heart Complex that has folic acid and Coenzyme Q10, a pure compound. These soft chews help promote normal circulation and support normal cardiovascular function. These dog multivitamins can be given daily in order to help keep your dog’s heart and body healthy. Note that multivitamins do not act as a treatment but are only supplemental to help provide your furbaby a sound and healthy heart.

Many of the underlying causes of heart murmur are treatable. The key is to catch it early and to address the disease as soon as possible. Frequent checkups will be needed to monitor how well your dog is responding to the treatment given by your vet and to ensure that the murmur has not gotten worse.