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Bradycardia (Heart Rate Lowered) in Dogs

Occurrence: rarer
Location of illness: Chest

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

BradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs is a condition in which the heart rate is lower than normal. This means that the heart beats slower than it should, which can lead to various health problems.

The most important facts at a glance

Bradycardia in dogs occurs when the electrical system of the heart is disrupted, resulting in a slow heartbeat. The sinus node in the right 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). is normally responsible for controlling the heart rate. Causes can include diseases of the sinus node, heart blockages, as well as systemic problems such as hypothyroidism or electrolyte disorders. Certain medications and nervous system disorders can also triggerA trigger is a stimulus that elicits a specific reaction or state. In veterinary medicine, this can refer to emotional responses, such as fear or aggression, or medical conditions, such as seizures in dogs and cats. bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease.. Symptoms range from weakness and reduced resilience to seizures and brief loss of consciousness. 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. is made through a physical examination, ECG, and possibly further tests such as blood tests or 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.. Treatment depends on the cause; in the case of medication-related bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease., an adjustment of the medication may be necessary, while in severe cases a pacemaker may be required. Medications such as atropine can help to increase the heart rate. The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. varies but is generally good if the cause is treated. PreventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. includes the management of underlying diseases, regular veterinary examinations, and a healthy lifestyle. Research focuses on genetic factors, new medications, and diagnostic tools to improve the treatment and 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 bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs.

Causes

Bradycardia occurs when the electrical system of the heart, which normally controls the rhythm and frequency of heartbeats, is disrupted. In a healthy heart, the sinus node, located in the right 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). of the heart, initiates the electrical impulses that stimulate the heart muscle to contract. A disturbance in this area can lead to a slow heart rate.

There are several causes of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs. A common cause is a disease of the sinus node itself, known as sick sinus syndromeA syndrome is a group of symptoms that occur together and indicate a specific disease or condition. A syndrome can be caused by various factors and is often complex in its diagnosis and treatment.. Other causes may include heart blockages, in which the electrical signals are not properly conducted through the heart. Systemic diseases such as hypothyroidism or electrolyte disorders can also lead to bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease..

Some medications, especially those used to treat heart problems, can also cause bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease.. These include beta-blockers and certain calciumCalcium is a mineral that is essential for building and maintaining strong bones and teeth. It also plays a role in blood coagulation, nerve transmission, and muscle contraction. channel blockers. Finally, nervous system disorders or increased vagal nerve activity can also play a role.

Symptoms

Very common symptoms:

Common symptoms:

Rare symptoms:

The symptoms of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs can be subtle and develop slowly. The most common signs include lethargy, weakness, and a decreased joy of movement. Dogs with bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. may also show reduced resilience and tire more quickly than normal.

In more severe cases, collapse or fainting spells may occur, especially during or after exertion. These episodes are called 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.. Another possible symptom is a pale or bluish discoloration of the mucous membranes, which indicates an insufficient oxygen supply to the body.

Some dogs may also show signs of respiratoryRespiratory refers to breathing or the process of breathing. Respiratory diseases affect the respiratory tract and can impair the ability to breathe effectively. distress, especially during physical activity. An unusually slow heartbeat may be noticeable during a veterinary examination, even if no other symptoms are obvious.

Diagnosis

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 bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. usually begins with a thorough physical examination by the veterinarian, who measures the dog’s heart rate and looks for signs of cardiac arrhythmiaAn arrhythmia is a heart rhythm disorder in which the heart beats irregularly, either too fast (tachycardia), too slow (bradycardia), or with an irregular pattern. Arrhythmias can be harmless or a sign of serious heart problems.. A complete 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. is also important to identify possible underlying causes.

ElectrocardiogramSee ECG. (ECG) is an important diagnostic tool to assess the electrical activity of the heart and identify specific types of cardiac arrhythmiaAn arrhythmia is a heart rhythm disorder in which the heart beats irregularly, either too fast (tachycardia), too slow (bradycardia), or with an irregular pattern. Arrhythmias can be harmless or a sign of serious heart problems.. An ECG can show whether the bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. is due to a sinus node problem or a heart blockage.

Further diagnostic tests may include blood tests to rule out systemic causes such as electrolyte disorders or thyroid problems. In some cases, a chest X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions. or a cardiac 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. may be performed to identify structural problems of the heart.

Therapy

The treatment of bradycardia depends heavily on the underlying cause. If there is a specific condition such as hypothyroidism or an electrolyte disorder, treating the underlying condition can normalize the heart rate.

In cases where bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. is caused by medication, the veterinarian may adjust the medication or consider alternative treatment options. If the bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. is severe and leads to symptoms such as syncope, the use of a pacemaker may be necessary to regulate the heart rhythm.

In addition, medications such as atropine or theophylline can be used to increase the heart rate. These medications work by reducing the influence of the vagus nerveThe vagus nerve is the tenth cranial nerve and plays a central role in the parasympathetic nervous system. It affects the function of many internal organs, including the control of heart rate, gastrointestinal motility, and respiration in dogs and cats. on the heart or improving the conduction in the heart.

Prognosis and follow-up care

The prognosis for dogs with bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. varies depending on the cause and severity of the condition. Dogs with mild forms of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. who do not show symptoms usually have a good prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. and can live a normal life, especially if the underlying cause is successfully treated.

In dogs with severe bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. that leads to 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 other serious symptoms, the prognosis may be more cautious, especially if a pacemaker is required. However, the quality of life can be significantly improved through appropriate medical measures.

Long-term follow-up and regular veterinary check-ups are important to monitor heart health and detect possible complications early.

Prevention

The preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. focuses primarily on avoiding and managing underlying conditions that can affect the heart rhythm. A regular veterinary examination can help to detect and treat potential health problems early.

If your dog is taking medications that could increase the risk of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease., it is important to discuss the dosage and possible side effects with your veterinarian. A balanced diet and regular exercise can also contribute to heart health.

For dogs that are prone to heart problems, it can be helpful to pay attention to stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. and excessive exertion, as these factors can further impair heart function. Close cooperation with your veterinarian can help ensure the best possible care for your dog.

Outlook on current research

Bradycardia in dogs is an interesting area of research that has gained increasing attention in recent years. BradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease., defined as a decreased heart rate, can be a symptom of various health problems, such as heart disease, metabolicMetabolic refers to metabolism, i.e. the entirety of chemical processes that take place in a living organism to enable life processes. Metabolic disorders can cause a variety of Diseases in Dogs and cats. disorders, or even neurological problems. Currently, research is focused on identifying the underlying causes as well as developing effective treatment strategies. Scientists are particularly investigating the role of genetic factors and how these may influence the susceptibility to bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease..

A promising direction of research is investigating the effect of medications and herbal remedies on heart rate. Studies have shown that certain medications used to treat bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in humans may also be effective in dogs. Furthermore, the role of nutrition and lifestyle in the development of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. is being investigated. Researchers are trying to find out whether certain diets or nutritional supplements can positively influence the heart rate in dogs.

Another area of research focuses on the development of new diagnostic tools. The use of portable ECG monitors that can continuously monitor a dog’s heart rate is an exciting development in veterinary medicine. Such devices could help veterinarians detect and monitor bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. early. In addition, the role of imaging techniques such as 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. and MRI 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 structural heart abnormalities that could lead to bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. is being further investigated.

Research in this area is also related to the investigation of the effects of environmental factors on the heart health of dogs. Scientists are investigating how stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being., temperature, and physical activity can affect heart rate. Behavioral studies that examine how dogs respond to various environmental stimuli and how these responses affect heart rate are also of interest.

The interdisciplinary collaboration between veterinary physicians, cardiologists, and nutritionists plays a crucial role in advancing our understanding of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs. Such collaborations help to develop more comprehensive treatment approaches that consider both the physiological and psychologicalPsychological refers to anything related to the mind or behavior. In veterinary medicine, this can include the study of animal behavior, including stress responses and behavioral disorders. aspects of the disease. In the long term, this could lead to personalized treatment plans that are tailored to the specific needs of each affected dog.

Overall, current research shows promising progress 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. and treatment of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs. The continuous advancement of technologies and the increasing understanding of the underlying biological mechanisms will certainly contribute to improving the quality of life of dogs with bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. and prolonging their life expectancy. It is hoped that future studies will provide even more comprehensive insights into the disease and its treatment options.

Frequently asked questions (FAQs)

What is bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs? BradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs is a condition in which the heart rate is lower than normal. The normal heart rate of a dog varies depending on size, age, and breed, but generally a heart rate below 60 beats per minute is considered bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease..
What are the symptoms of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs? The symptoms can be non-specific and include lethargy, weakness, collapse, respiratoryRespiratory refers to breathing or the process of breathing. Respiratory diseases affect the respiratory tract and can impair the ability to breathe effectively. distress, or even fainting. Some dogs may not show any symptoms at all, especially in the early stages of the disease.
What causes bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs? The causes can be varied and range from genetic factors to heart diseases to metabolicMetabolic refers to metabolism, i.e. the entirety of chemical processes that take place in a living organism to enable life processes. Metabolic disorders can cause a variety of Diseases in Dogs and cats. disorders such as hypothyroidism. Certain medications or overstimulation of the vagus nerveThe vagus nerve is the tenth cranial nerve and plays a central role in the parasympathetic nervous system. It affects the function of many internal organs, including the control of heart rate, gastrointestinal motility, and respiration in dogs and cats. can also cause bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease..
How is bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. diagnosed? The diagnosis usually begins with a thorough clinical examination by the veterinarian, followed by an ECG to monitor the heart rate. Further diagnostic tests may include blood tests, X-rays, or 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. examinations.
Can bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs be treated? Yes, the treatment depends on the underlying cause. Possible treatment approaches include adjusting medications, treating underlying diseases, or, in severe cases, implanting a pacemaker.
Is bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. in dogs life-threatening? In some cases, bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. can be life-threatening, especially if it leads to circulatory failure. However, timely 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 treatment can significantly reduce the risk of serious complications.
Can all dog breeds develop bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease.? Yes, bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. can occur in any dog breed, although some breeds may have a genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases.. Larger dog breeds tend to have a lower normal heart rate, which can complicate 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..
Can diet play a role in bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease.? A balanced diet is important for overall health, including heart health. Certain nutrient deficiencies or excesses could indirectly affect heart rate, which is why a balanced diet is recommended.
How can I help my dog with bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease.? If your dog has bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease., you should have regular veterinary check-ups and follow your veterinarian’s treatment recommendations. Make sure your dog receives a balanced diet and monitor his physical activity.
Are there preventive measures against bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease.? While not all cases of bradycardiaBradycardia refers to a slower than normal heart rate, typically below 60 beats per minute in adults. It can occur in healthy individuals, especially athletes, but can also be an indication of heart disease. can be prevented, a healthy lifestyle, including regular exercise and a balanced diet, can contribute to overall heart health. Regular veterinary examinations can help to detect and treat early signs.