The moment when one of our trusted veterinarians at Oakhurst Veterinary Hospital looks up at you and asks, “Has anyone ever mentioned to you that your pet has a heart murmur” is enough to cause most people’s heart to sink. A heart murmur can’t be good news, can it?
All heart murmurs in pets are not created equally, however, and most of them don’t mean imminent demise. Understanding what heart murmurs in pets mean can help you to take better care of your furry patient.
Do You Hear That?
A heart murmur is just what it sounds like – an unexpected sound mixed in the “lub-dub” of a normal heart beat. When something sounds off during our heart auscultation, it is termed a heart murmur.
A murmur is caused by turbulence in the flow of blood through the chambers of the heart. There can be many things that cause this, from very benign to more serious.
When a heart murmur is identified, it is then described. This description can help to determine likely potential causes. Heart murmurs in pets are described using:
- Point of maximum intensity – This is simply a fancy phrase used to describe where on the patient the murmur is best heard. On the left side? The right? Apically (near the widest part of the chest)? All over?
- Timing – At what point in the heartbeat cycle the murmur is heard can also be important. Murmurs may be systolic (during or after lub) or diastolic (during or after dub). They may be continuous as well, incorporating both systole and diastole.
- Grade – Heart murmurs are also graded on a scale of 1 to 6 based on their loudness and intensity. While it might be logical to assume that a grade 6 murmur is more serious than a grade 1, this is not always the case. The loudness of a murmur has no correlation with the consequences of it.
Causes of Heart Murmurs in Pets
We already disclosed that heart murmurs in pets can have a myriad of underlying causes. Anything that changes normal blood flow within the heart’s chambers can result in an abnormal sound.
Some of the more common reasons we might hear a murmur can include:
- A heart valve that is leaking, allowing some blood to flow the wrong direction
- A thickened heart valve
- A narrow heart valve opening
- An abnormal hole between the walls of the heart chambers
- Abnormal connection of large blood vessels
- Anemia or other conditions that alter the viscosity of the blood
- Infections such as heartworm infection
The causes of heart murmurs in pets may be congenital (something the pet was born with) or acquired (developed).
When a pet has been diagnosed with a new murmur, the next logical step is to determine what is causing it. This helps not only to help us understand how worried we need to be, but it can also help us to tailor an effective treatment for your pet.
Diagnostic testing such as chest radiographs (x-rays), bloodwork, heartworm testing, heart rhythm tracing (ECG), and heart ultrasound (echocardiogram) are often recommended. Some heart murmurs do not cause any issues, but we must know what we’re treating before we can make that assumption.
Treatments vary depending on the type of heart murmur:
- Several medications exist that can help to improve heart function.
- Some heart problems, particularly those that are congenital in nature, may have surgical recommendations.
- Sometimes, especially if a murmur is without symptoms, we may simply choose to monitor it. In this scenario we recommend having one of our doctors examine your pet at least twice annually. We may also ask you to monitor resting respiration rate at home.
For all pets with a heart murmur, proactive care to help your pet’s heart function at peak capacity is important. Staying vigilant on administration of heartworm prevention, providing good dental care, and feeding a good diet rich in omega-3 fatty acids is important.
When a pet has a heart murmur, we are here for you. Please don’t hesitate to ask if you have questions or concerns. Every pet is different, and we are happy to help create a personalized game plan for each and every situation.