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Heart Murmur in Dogs

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

If the condition worsens / symptoms persist, consult a veterinarian.

Unsure about what’s wrong with your pet? Feel free to use our Symptom Checker for more clarity

A heart murmur in dogs is an abnormal sound that occurs during the heart’s action and is detected during auscultationAuscultation is an examination method in which the doctor uses a stethoscope to listen to the sounds in the body, especially in the heart, lungs, and intestines, in order to obtain information about the state of health., which is listening with a stethoscopeA stethoscope is a medical instrument used for auscultation, or listening to body sounds, such as heartbeats and lung sounds. It is a fundamental tool in medical diagnostics.. These sounds are often signs of an underlying heart disease or other health problems.

Can Occur with the Following Diseases:

Grundlagen und mögliche Ursachen

Heart murmurs are caused by turbulent blood flow within the heart or in the large vessels leaving the heart. This turbulence can be caused by structural abnormalities of the heart valves, defects in the heart structure, or changes in blood viscosityBlood viscosity refers to the blood's resistance to flow. High viscosity means the blood is thicker, which can impede blood flow and lead to health problems. Factors that affect blood viscosity include the number of blood cells and protein content.. Normal blood flow is laminar and silent, while turbulence creates audible vibrations.

One of the most common causes of heart murmurs in dogs is valve disease. These usually affect the mitral valve and the aortic valve. In mitral valve insufficiencyInsufficiency refers to the inadequate function or performance of an organ or system. This can include, for example, heart failure, kidney failure, or venous insufficiency., for example, the valve does not close properly, leading to a backflow of blood into the atriumThe atrium (plural: atria) is one of the two upper chambers in the heart that receive blood from the body (right atrium) or from the lungs (left atrium).. This creates the characteristic sound. Aortic valve stenosisA stenosis is a narrowing or constriction of a body channel or opening that can impede the normal flow of fluids or other substances, such as blood in arteries or air in the airways., on the other hand, is a narrowing of the aortic valve that obstructs blood flow from the left ventricleA ventricle is one of the two lower chambers of the heart that pump blood into the arteries. The right ventricle pumps blood to the lungs, while the left ventricle pumps blood throughout the body..

Heart murmurs can also be caused by congenitalCongenital means "present from birth" and refers to characteristics or conditions that are already present at birth. This can include genetic disorders, developmental anomalies, or infections transmitted by the mother. heart defects such as patent ductus arteriosus or ventricular septal defects. These defects lead to abnormal connections within the heart or between the large vessels, causing turbulence.

Additionally, heart murmurs can be functional, meaning they occur without structural heart abnormalities. Such functional murmurs can be caused by anemia, Fever, or an overactive thyroid, which accelerate blood flow and change the viscosity of the blood.

Typische Begleitsymptome

Cough: A common accompanying symptom, often caused by fluid accumulation in the lungs or pressure on the airways due to heart failure.
Exercise intolerance: Dogs with heart problems often show decreased stamina and fatigue during activities that they used to be able to handle without any problems.
RespiratoryRespiratory refers to breathing or the process of breathing. Respiratory diseases affect the respiratory tract and can impair the ability to breathe effectively. distress: RespiratoryRespiratory refers to breathing or the process of breathing. Respiratory diseases affect the respiratory tract and can impair the ability to breathe effectively. distress can be a sign of advanced heart disease, especially if the dog is breathing heavily at rest or while sleeping.
Dropsy (ascites): Fluid accumulation in the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity can be caused by Heart failure, especially in right-sided heart failureRight-sided heart failure is a condition in which the right side of the heart is unable to effectively pump blood to the lungs. In dogs and cats, this can lead to fluid accumulation in the body, especially in the abdominal cavity, and reduced oxygen supply..
SyncopeA syncope is a sudden, temporary loss of consciousness, usually due to a brief drop in blood pressure and reduced blood flow to the brain. Syncopes can be triggered by various factors, including stress or heart problems. (fainting spells): These can occur when the heart no longer pumps enough blood into the circulation, leading to a temporary lack of oxygen in the brain.
Blue coloration of the mucous membranes (cyanosisCyanosis refers to a bluish discoloration of the skin and mucous membranes, caused by an inadequate oxygen supply to the blood. It can be a sign of heart, lung, or blood diseases.): This indicates an insufficient oxygen supply to the blood, which can be caused by heart or lung problems.
Weight loss: A chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. heart problem can lead to loss of appetite and thus to Weight loss.

Wann zum Tierarzt?

A visit to the vet is urgently required if your dog shows one or more of the symptoms mentioned. Action should be taken immediately, especially in cases of dyspneaDyspnea, also known as shortness of breath, is the subjective feeling of breathlessness or difficulty breathing. It can be a symptom of a variety of conditions, including heart disease, lung disease, and anemia., syncopeA syncope is a sudden, temporary loss of consciousness, usually due to a brief drop in blood pressure and reduced blood flow to the brain. Syncopes can be triggered by various factors, including stress or heart problems., or bluish mucous membranes, as these signs can indicate acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. heart failure.

Even if your dog only has a heart murmur but no other symptoms, a veterinary check-up is advisable. Heart murmurs can be the first indicationIndication refers to a valid reason or rationale for using a specific treatment, medication, or medical procedure. It is based on the diagnosis and the patient's clinical condition. of beginning heart disease that requires early therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions..

Regular check-ups are particularly important if your dog belongs to a breed that is predisposed to heart disease, such as Cavalier King Charles Spaniels or Boxers.

Symptomerkennung für den Tierhalter und tierärztliches diagnostisches Vorgehen

For the pet owner, it is often difficult to recognize heart murmurs without veterinary help, as they are detected during auscultationAuscultation is an examination method in which the doctor uses a stethoscope to listen to the sounds in the body, especially in the heart, lungs, and intestines, in order to obtain information about the state of health. with a stethoscopeA stethoscope is a medical instrument used for auscultation, or listening to body sounds, such as heartbeats and lung sounds. It is a fundamental tool in medical diagnostics.. However, the symptoms described above may be an indicationIndication refers to a valid reason or rationale for using a specific treatment, medication, or medical procedure. It is based on the diagnosis and the patient's clinical condition. that a more thorough examination is necessary.

The veterinarian will first take a thorough medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. and examine the dog clinically. During this, the heart is listened to with a stethoscopeA stethoscope is a medical instrument used for auscultation, or listening to body sounds, such as heartbeats and lung sounds. It is a fundamental tool in medical diagnostics. to localize and characterize the sound. The volume, the timing in the cardiac cycle, and the duration of the sound can provide clues to the type of underlying disease.

For further clarification, imaging procedures such as chest X-rays, a heart ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. (echocardiographyEchocardiography is an ultrasound examination of the heart that assesses the structure and function of the heart valves and chambers. It can provide information about heart size, pumping function, and the presence of heart disease.), or an electrocardiogramSee ECG. (ECG) are used. These examinations help to identify the exact cause of the heart murmur and determine the severity of the disease.

Was kann der Tierhalter tun und professionelle Therapieoptionen

As a pet owner, you can take some measures to support your dog’s health and avoid major damage. First, make sure your dog maintains a healthy weight, as being Overweight puts additional strain on the heart. A balanced diet and regular exercise are crucial for this.

Avoid stressful situations and physical overexertion for your dog, especially if heart problems have been diagnosed. Talk to your vet about suitable activity levels and possible therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. options to minimize the strain on the heart.

Medical treatments may be necessary to support heart function and relieve symptoms. These can include diureticsDiuretics are medications that increase urine production in the kidneys to rid the body of excess salt and water. They are often used to treat high blood pressure, heart failure, and certain types of edema., ACE inhibitors, or beta blockers, depending on the specific diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients.. Strictly follow your vet’s instructions regarding medication.

Regular follow-up appointments with the vet are important to monitor the progress of the heart disease and adjust the therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. if necessary. Inform your vet about any changes in your dog’s behavior or health so that they can intervene in time.

Ausblick auf aktuelle Forschung

Heart murmurs in dogs are a common symptom that is often discovered by chance during veterinary examinations. Current research is focused intensively on developing more precise diagnostic methods to better narrow down the underlying causes of heart murmurs. A significant advance in this area is the use of advanced echocardiographyEchocardiography is an ultrasound examination of the heart that assesses the structure and function of the heart valves and chambers. It can provide information about heart size, pumping function, and the presence of heart disease. and Doppler ultrasound technology, which allows for a more detailed visualization of the heart structure and blood flow. These technologies help distinguish between harmless and pathologicalPathological refers to anything related to diseases or their processes. Pathological changes are those that deviate from the normal structure or function and indicate a disease. heart murmurs, which is crucial for the treatment and management of affected dogs.

Another significant area of research is the genetic analysis of heart murmurs. Scientists are investigating the extent to which genetic factors play a role in the development of heart murmurs. By identifying specific genetic markers, researchers hope to better understand which dogs are at a higher risk for serious heart problems. In the long term, this could lead to the development of genetic tests that help in the early detection of high-risk patients.

Research into the long-term impact of heart murmurs on the quality of life and life expectancy of dogs is also gaining importance. Studies tracking the clinical progress of dogs with heart murmurs over several years provide valuable data on which factors influence the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of potential heart disease. This information is crucial for developing better therapeutic strategies that can improve the well-being and lifespan of affected dogs.

In addition, there are innovative studies dealing with the role of diet and lifestyle in the development and management of heart murmurs. Some research teams are investigating whether certain diets or supplements can reduce the risk of heart problems. These studies could lead to new recommendations that have a preventive effect and slow the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of heart disease.

An interesting field of research deals with the application of Artificial Intelligence (AI) and machine learning in the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of heart murmurs. Algorithms are being developed to analyze heart sounds from audio recordings and automatically distinguish between normal and abnormal sounds. These technologies could make it easier for veterinarians to evaluate heart sounds more accurately and make faster, more precise diagnoses.

In summary, research into heart murmurs in dogs is a dynamic field that benefits from technological innovations and a better understanding of genetic and environmental factors. These advances help improve the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and management of heart murmurs, thereby promoting the health and well-being of our four-legged friends.

Häufig gestellte Fragen

What is a heart murmur in dogs? A heart murmur is an unusual sound heard during a dog’s heartbeat cycles during a veterinary examination. It is caused by turbulent blood flow in the heart or large blood vessels.
How is a heart murmur diagnosed in dogs? Heart murmurs are usually discovered by listening with a stethoscopeA stethoscope is a medical instrument used for auscultation, or listening to body sounds, such as heartbeats and lung sounds. It is a fundamental tool in medical diagnostics. during a routine examination. Further diagnostic tests, such as an echocardiographyEchocardiography is an ultrasound examination of the heart that assesses the structure and function of the heart valves and chambers. It can provide information about heart size, pumping function, and the presence of heart disease., may be required to determine the exact cause.
Are all heart murmurs serious in dogs? Not all heart murmurs are serious. They can range from harmless, so-called functional sounds to those that indicate serious heart problems. An accurate diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. by a vet is important.
What symptoms can occur in dogs in addition to heart murmurs? In addition to heart murmurs, symptoms such as cough, respiratoryRespiratory refers to breathing or the process of breathing. Respiratory diseases affect the respiratory tract and can impair the ability to breathe effectively. distress, decreased performance, fainting spells, or a bloated abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen. may occur, depending on whether there is an underlying heart disease.
Can heart murmurs be treated in dogs? The treatment for heart murmurs depends on the underlying cause. Harmless sounds may not require any treatment, while serious heart diseases may require medication or even surgical intervention.
Can puppies have heart murmurs? Yes, puppies can have heart murmurs, which are often harmless and referred to as “physiological” or “functional” sounds. These often disappear on their own as the puppy grows.
Should I worry if my dog has a heart murmur? It is advisable to have a veterinary examination to clarify the cause of the heart murmur. Some sounds are harmless, but others can indicate heart problems that should be treated.
Can heart murmurs occur suddenly in dogs? Heart murmurs can appear suddenly, especially if they are caused by acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. illnesses. However, they are more commonly discovered during routine examinations.
How often should a dog with a heart murmur be monitored by a veterinarian? The frequency of monitoring depends on the cause and severity of the heart murmur. Your vet will suggest a suitable monitoring plan, which may include regular examinations and possibly further tests.
Can diet affect my dog’s heart health? Yes, diet can play an important role in heart health. A balanced diet rich in omega-3 fatty acids and low in sodiumSodium is a vital electrolyte that plays a key role in regulating water balance, blood pressure, and nerve and muscle activity. Unbalanced sodium levels can lead to various health problems in dogs and cats. can reduce the risk of heart problems. Your vet can give specific recommendations for your dog.