Dog heart murmur.

There is not much arguing about it: the heart is a pretty important part of the body, be it in an animal or a person. When something is wrong with it, the results can be pretty devastating.

Heart murmurs in pets are not uncommon, but thankfully not all of them are panic-worthy. Animal Medical Hospital & Urgent Care hopes to help pet owners understand a little more about heart murmurs in pets and what to do about them.

Go With the Flow

The heart has a pretty vital role in the physiology of animals. It needs to circulate blood throughout the body in order to oxygenate the blood and deliver that oxygen to every extremity. From the tips of the toes to the top of the brain, the heart must adequately deliver oxygenated blood.

In essence, the heart is a living pump, moving blood throughout its four chambers (two atria and two ventricles) before sending it back out into the body. The process of moving blood through the body works in the following way:

  • Oxygen depleted blood enters the right atrium through the vena cava
  • The blood then flows into the right ventricle through the triscupid valve
  • Blood then flows through the pulmonic valve into the lungs to be oxygenated
  • After oxygenation, the blood return to the left atrium
  • The left atrium then contracts, moving the oxygen-rich blood into the left ventricle through the mitral valve
  • The blood then leaves the left ventricle through the aortic valve into the aorta to bring oxygen to the rest of the body

Coordinated muscle contraction and the functional opening and closing of the four valves to prevent the backflow flow of blood is very important to be sure that this is an efficient system.

Heart Murmurs in Pets 

Anything that disrupts the forward and streamlined flow of blood through the heart can lead to extra noise in the normal “lub-dub” our veterinarians auscult with their stethoscope. This is called a heart murmur. 

Heart murmurs in pets are graded on a scale of one-to-six by their loudness. They may also be described by the time they occur in the heartbeat (systolic, diastolic, etc.) and where they are heard most loudly.

While the grade of a heart murmur can tell us more about the murmur and its potential causes, grade does not equate to severity. A very loud murmur can have very little effect on the function of the heart, while a quiet murmur may lead to serious consequences.

There can be many causes for heart murmurs in pets. Some of the more common underlying reasons include:

  • A heart valve that is leaking or damaged in some way
  • A thickened or narrowed valve or major vessel
  • An abnormal opening between the heart chambers
  • Abnormal connections of major blood vessels
  • Changes in the heart muscle
  • Anemia or other changes in blood viscosity

Heart Healthy

So what is a pet owner to do if their pet is diagnosed with a heart murmur? Heart murmurs in pets can be caused by so many different things that may carry different consequences. Further diagnostics are almost always in order to determine the cause of the new finding. 

A cardiology workup may include things like radiographs, blood work, echocardiogram (ultrasound), nutritional evaluation, and electrocardiography to evaluate the cause, the severity, and the best treatment for a murmur. 

You can also take steps to support heart health at home. Be sure to:

  • Feed a healthy, recommended diet
  • Maintain a healthy weight for your pet
  • Encourage healthy activity and exercise
  • Keep up on wellness visits 
  • Keep your pet on heartworm prevention year-round
  • Consider using omega-3 fatty acids if deemed appropriate for your pet
  • Make sure to provide good dental care (periodontal disease can affect the heart)

While we encourage you to bring your pet in for regular wellness visits so that we can monitor things like heart health closely, you should also pay close attention if you know that your pet has a murmur. 

Call us right away if you notice that your pet is having faster or heavier breathing at rest, is coughing, or seems to have less exercise tolerance than normal. These can all be signs of congestive heart failure and need to be assessed as soon as possible.
Heart murmurs in pets happen, but not all of them have to be scary. Your pets are in good hands with Animal Medical Hospital & Urgent Care. We promise to do our best to determine the cause and best options for your furry family member.