Heart murmurs in horses

Understanding heart murmurs from both a conventional and TCVM perspective will help you make the best decisions for your horse’s health.

Researchers estimate that anywhere from 3% to 81% of horses may have a heart murmur. These statistics demonstrate quite a spread. This huge range may be due to different populations of different types of horses being evaluated between multiple studies around the world. Regardless, the point is that heart murmurs are a common finding in horses. While most of the horses studied had no performance detriments, early identification of heart murmurs may help with longevity and quality of life, especially when the heart’s function is understood from both a conventional and alternative medical perspective.

Understanding heart sounds

Understanding heart murmurs in horses means first understanding the heart and the sounds it makes as part of its normal function. It’s fairly common knowledge that the heart is a four-chambered organ. Between each chamber are valves that keep blood moving forward through the heart. Normal heart sounds are created when the valves close.

Typically, the healthy heart makes two sounds which often sound like “lubb-dupp”. The first sound is associated with the valves at the top of the heart closing. The second sound is associated with the lower valves closing. Technically, each valve makes its own sound when it closes; simultaneous closing makes it difficult to hear each sound. Some people are surprised to learn that it’s common to hear three hearts sounds in the very athletic horse. This third sound is associated with the wave of blood moving into the chamber and hitting the wall of the heart muscle. When there are three heart sounds present, it sounds like “lubb-dupp-dupp.“ The third sound will be low in pitch like the other normal heart sounds. All these heart sounds can be heard through auscultation with a stethoscope over different areas of the chest wall.

So what is a heart murmur?

By definition, heart “murmur” means there are extra heart sounds. Heart murmurs are not only associated with age changes; in some horses, especially young foals, the heart may not have completed its formation, or may not have formed correctly, and may have extra sounds – murmurs. Sometimes these foals outgrow the condition, sometimes it persists. In a retired pasture horse, it would be unusual to hear extra heart sounds.

As just suggested, the presence of a heart murmur does not always indicate problems. In cases of problematic heart murmurs, the sounds will be higher-pitched, less uniform, and the horse may suffer from reduced performance. In some extreme cases, the heart may sound like a top-loading washing machine sloshing its water around. The washing machine sound comes from an inability of the heart valves to prevent a backflow of blood between the chambers as it squeezes. In these horses, a jugular pulse is often present.

It is normal to see a little bit of pulse in the neck when a horse puts his head down. However, a jugular pulse will travel more than halfway up the neck in a heart murmur patient who is experiencing difficulties, even when the horse’s head is up. The murmur, its associated sounds, and the jugular pulse all occur due to inefficiencies in the heart’s ability to pump blood forward. Inefficiencies can be due to leaky valves, a damaged heart muscle, or even a hole in the heart muscle.

A heart murmur can become a sign of a failing heart, especially in aging horses. While potentially a serious medical condition, many things can be done to help the horse with a heart murmur if it’s detected early enough. Understanding the heart’s function from an alternative perspective provides valuable insight.

Using TCVM for diagnosis and support

Interestingly, Traditional Chinese Veterinary Medicine (TCVM) not only evaluates health or dysfunction based on heart sounds, but further differentiates abnormalities by TCVM patterns. Through auscultation, attention to other clinical signs such as tongue color and size, as well as pulse quality, the TCVM practitioner further differentiates heart murmur cases to determine exact treatment protocols. By contrast, conventional medicine tends to lump all clinical heart murmur cases into only a few groups and treat them accordingly; heart murmurs are graded on a scale of I to VI, with I being very difficult to hear and VI being the washing machine sound discussed previously.

The TCVM view of the Heart is different than the conventional view. As you’ll see, the word “Heart” is capitalized to indicate the TCVM organ which does not entirely correlate to the structural organ, the heart. The Heart is connected to its related organ, the Small Intestine via acupuncture meridians; there are times when addressing the Small Intestine can help the Heart function. The Heart is considered to be the king of the internal organs because it plays the most important function. Not only does the Heart propel blood through the blood vessels, it also houses the Shen (basically, the mind), controls sweat and has an opening to the tongue according to TCVM theory.


It is said that the Heart dominates Blood contained in blood vessels, meaning it governs the circulation of Blood. The Heart is the machine that propels blood forward, which is similar to the conventional concept of the heart as a pump. The Heart’s ability to maintain Blood flow depends on the energy or Qi (pronounced chee) of the Heart. When the Qi is strong, the Blood will circulate through the vessels, supplying nutrients to the body. When the Heart’s Qi and/or its Blood is weak (deficient), there will be a weak pulse and tongue color. In cases where a heart murmur is present, the Heart Qi is weak and often Heart Blood is deficient.


In Chinese medicine, a weak or deficient Heart will also lead to disturbances in mental or emotional aspects. The weak Heart Blood does not anchor the mind (Shen), thus it’s at the mercy of the outside environment, like a dinghy in a windstorm. Some horses with heart conditions may undergo behavior changes; this correlation is explained in TCVM but not directly recognized in conventional medicine. Because the two can be explained through TCVM theory, it makes treatment logical as the entire issue is addressed together, rather than as two separate conditions.

Bodily fluids

Body fluids are derived from the Blood, according to TCVM theory. Because the Heart drives the Blood, it also drives perspiration or sweat; body fluids move between the Blood and the body surface to balance fluidity in the vessels. Abnormal sweating can relate to an imbalanced Heart. Some horses may experience either an increased or decreased ability to sweat depending on their progression of the heart condition.


Centuries ago, Chinese physicians noticed a correlation between the health of the tongue and the heart. In those with a deficient Heart, the tongue may be shriveled and small, and can even have a notch or discoloration at the tip. When the Heart is healthy, the tongue is moist, movable and peachy red. Often, an astute owner and/or TCVM practitioner will notice changes in the horse’s tongue before there is any indication of heart dysfunction. As the external opening to the Heart, the tongue is a great early indicator of the internal condition of the heart.


Together, conventional and TCVM theory can be used to help the horse owner detect early changes that can suggest a horse with an asymptomatic heart murmur may be progressing in symptomology. Furthermore, while conventional medicine often leaves asymptomatic heart murmurs untreated, TCVM theory would identify the horse’s underlying pattern and work to maintain heart health before failure begins. In symptomatic cases, TCVM treatment may be sufficient, or a combination of therapies may work best to extend quality of life. For this reason, working with an integrative equine practitioner may provide for the best equine health.