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Cardiac Arrest (Herzstillstand) in Dogs

Synonyms: Cardiovascular arrest, circulatory failure, cardiac arrest, clinical Death

Occurrence: common
Location of disease: Chest

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

When to visit the vet?

Emergency see a veterinarian immediately

Definition

Cardiac arrest in dogs is a sudden interruption of heart function, leading to an immediate loss of heartbeat and blood flow. This is a life-threatening condition that requires immediate emergency medical attention.

The most important facts at a glance

Cardiac arrest in dogs occurs when the heart suddenly stops beating, which stops blood flow and prevents vital organs from receiving oxygen. This can be caused by heart disease, electrical heart disorders, traumas, or severe infections. Symptoms include the absence of a palpable pulse, unconsciousness, and circulatory system collapse. 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. is made through physical examination and ECG, and treatment requires immediate cardiopulmonary resuscitation (CPR)Cardiopulmonary resuscitation (CPR) is a life-saving procedure used in dogs and cats to restore heart and lung function when the heart has stopped beating. It includes chest compressions and artificial respiration.. In a hospital, additional measures such as administering medications or using a defibrillator may be necessary.

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. depends on the cause of the cardiac arrest and the effectiveness of the resuscitationResuscitation includes measures to revive animals after a cardiac arrest or severe respiratory depression. These may include chest compressions and artificial respiration. measures. PreventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. includes regular veterinary check-ups, a healthy diet, and exercise. Close monitoring is important in dogs with known heart problems. Research focuses on 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., improved diagnostic techniques, and new therapies to promote heart health and increase survival chances. Training veterinarians and owners in first aid for dogs is also an important aspect to enable quick action in an emergency.

Causes

The heart is a vital organ that pumps blood through the body. In the event of cardiac arrest, the heart suddenly stops beating, leading to an immediate drop in blood flow. This means that oxygen and nutrients no longer reach the vital organs, which can lead to serious damage or Death within minutes.

The causes of cardiac arrest in dogs can be varied. A common cause is heart disease, which can lead to a heart attack. Heart disease in dogs can be genetic or develop over the course of their lives due to factors such as an unhealthy diet or lack of exercise.

Another common cause of cardiac arrest is a severe electrical disturbance in the heart, such as ventricular fibrillationFibrillation is an irregular, often rapid heart rate that leads to a chaotic rhythm in the atria or ventricles of the heart. This can impair cardiac output and often requires medical treatment. or a progressiveProgressive describes a condition or disease that worsens over time. This term is often used to characterize the course of an illness that causes increasingly severe symptoms or damage. 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.. These disturbances can lead to an uncoordinated heartbeat that impairs the heart’s pumping function.

In addition, traumaA trauma refers to a physical injury or damage caused by external force. Traumas can range from simple cuts to severe multiple injuries., such as a heavy blow to the chest, or severe diseases affecting the entire body, such as severe infections or poisonings, can 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. cardiac arrest. The use of certain medications or anesthetics can also increase the risk of cardiac arrest.

Symptoms

Very common symptoms:

Common symptoms:

Rare symptoms:

Foamy Saliva

The symptoms of cardiac arrest in dogs occur suddenly and are very obvious. Common signs include immediate loss of consciousness and collapse of the animal. The dog shows no signs of breathing or heartbeat.

Other symptoms may include dilated pupils, pale or blue mucous membranes, and a complete loss of muscle tone. In some cases, there may be a brief, uncontrolled tremor or twitch before the dog becomes unconscious.

Since cardiac arrest is an 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. emergency, it is crucial that resuscitationResuscitation includes measures to revive animals after a cardiac arrest or severe respiratory depression. These may include chest compressions and artificial respiration. measures are initiated immediately: clear airway, ventilation, chest compressions. The dog must receive veterinary care as quickly as possible to minimize potential irreversible damage.

Cardiac arrest is an absolute emergency. Immediately initiate BLS/ALS measures for animals (clear airway, ventilation, chest compressions)

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 cardiac arrest in dogs is typically made through a physical examination and the absence of heart and breathing sounds. The veterinarian will immediately attempt to confirm the condition and begin life-saving measures.

Diagnostic tools such as an ECG (electrocardiogram)An electrocardiogram is a recording of the electrical activity of the heart over time. It is used to diagnose cardiac arrhythmia, damage to the heart muscle, and other heart problems. may also be used to check the heart’s electrical activity. This can help identify the cause of the cardiac arrest, such as an 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..

In some cases, especially if the dog is successfully resuscitated, further tests such as blood tests or imaging procedures may be performed to determine underlying conditions that may have caused the cardiac arrest.

Therapy

Treatment for cardiac arrest requires immediate cardiopulmonary resuscitation (CPR)Cardiopulmonary resuscitation (CPR) is a life-saving procedure used in dogs and cats to restore heart and lung function when the heart has stopped beating. It includes chest compressions and artificial respiration., which consists of chest compressions and rescue breaths. These measures should be started immediately to increase the chances of successful resuscitationResuscitation includes measures to revive animals after a cardiac arrest or severe respiratory depression. These may include chest compressions and artificial respiration..

If the dog is treated in a veterinary hospital, more advanced measures can be taken, such as administering heart-stimulating medications or using a defibrillator to restore a normal heart rhythm.

After successful resuscitationResuscitation includes measures to revive animals after a cardiac arrest or severe respiratory depression. These may include chest compressions and artificial respiration., intensive monitoring is necessary to ensure that the dog remains stable and that no further complications occur. This may require hospitalization and the administration of medications to support heart function.

Prognosis and follow-up care

The prognosis after cardiac arrest in dogs depends on various factors, including the cause of the cardiac arrest, the speed and effectiveness of the resuscitationResuscitation includes measures to revive animals after a cardiac arrest or severe respiratory depression. These may include chest compressions and artificial respiration. measures, and the dog’s general health.

Dogs that are resuscitated quickly and effectively have a better prognosis, but permanent damage can occur, especially if the brain has not received enough oxygen during the cardiac arrest.

Long-term survival rates often depend on the ability to treat and control the underlying cause of the cardiac arrest. In some cases, permanent medical treatment may be necessary.

Prevention

PreventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. of cardiac arrest in dogs can be achieved through regular veterinary check-ups to detect and treat heart disease early. A healthy diet and regular exercise are also important to promote heart health.

In dogs with known heart disease or genetic predispositions to heart problems, close monitoring and, if necessary, the administration of heart-supporting medications may be necessary to minimize the risk of cardiac arrest.

Owners should also familiarize themselves with the basic techniques of cardiopulmonary resuscitation (CPR)Cardiopulmonary resuscitation (CPR) is a life-saving procedure used in dogs and cats to restore heart and lung function when the heart has stopped beating. It includes chest compressions and artificial respiration. in dogs so that they can act quickly in an emergency until professional help arrives. Information can be found in [this article on dog resuscitation](https://vcahospitals.com/know-your-pet/cardiopulmonary-resuscitation-cpr-in-dogs-and-cats).

Outlook on current research

Research in the field of cardiac arrest in dogs focuses on various aspects that concern both understanding the causes and developing treatment strategies. An important area of research is the investigation of the 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. to cardiac arrest in certain dog breeds. Researchers are trying to identify genetic markers that could indicate which dogs have a higher risk of cardiac arrest. Such genetic studies could promote the breeding of healthier animals in the future and enable veterinarians to take preventive measures in a more targeted manner.

Another focus of current research is on improving diagnostic techniques. New imaging methods and biomarker diagnostics are being developed to detect heart disease earlier and more accurately. These advances could enable treatment of dogs at an earlier stage of the disease, thereby reducing the risk of cardiac arrest. Furthermore, research is being conducted on wearable devices that can continuously monitor heart activity and sound an alarm when abnormalities are detected.

In the area of therapeutic research, intensive work is being done on developing new medications and therapies. The goal is to find treatments that can effectively support or restore heart function after cardiac arrest has occurred. This includes research into stem cell therapies and the use of pacemakers or defibrillators in dogs. Such technological and medical advances offer promising prospects for treating dogs suffering from heart problems.

Finally, the education and training of veterinarians and pet owners is also regarded as an important area of research. The development of standardized protocols for emergency care and the implementation of first aid courses for cardiac arrest in pets are intended to help increase the chances of survival of dogs in the event of cardiac arrest. This training can be crucial in reducing the time to initiate life-saving measures.

Frequently asked questions (FAQs)

What is cardiac arrest in dogs?

Cardiac arrest in dogs occurs when the heart suddenly stops beating, leading to an immediate loss of blood circulation in the body. This condition is a medical emergency and requires immediate action to save the animal's life. -

What are the most common causes of cardiac arrest in dogs?

The most common causes include severe heart disease, such as cardiomyopathy or heart valve problems, as well as traumas, severe infections, and poisonings. Genetic factors and age can also play a role. -

What symptoms can precede cardiac arrest in dogs?

Before cardiac arrest, symptoms such as weakness, shortness of breath, Cough, collapse, or fainting may occur. These signs require immediate veterinary examination. -

How is cardiac arrest treated in dogs?

Treatment includes immediate cardiopulmonary resuscitation (CPR) and, if necessary, the use of a defibrillator to restart the heart. Intensive medical care is then necessary to treat the cause of the cardiac arrest. -

Can dogs fully recover after cardiac arrest?

Recovery depends on the cause of the cardiac arrest and the speed of emergency assistance provided. With timely and effective treatment, some dogs can fully recover, while others may have persistent health problems. -

How can I reduce the risk of cardiac arrest in my dog?

Regular veterinary check-ups can help detect heart disease early. A balanced diet, sufficient exercise and avoiding Overweight are also important to support your dog's heart health. -

Are there certain breeds that are more prone to cardiac arrest?

Yes, certain breeds such as Dobermans, Boxers, and Cavalier King Charles Spaniels have a higher risk of heart disease that can lead to cardiac arrest. It is important to pay particular attention to heart health in these breeds. -

Can cardiac arrest occur in dogs without warning?

Yes, in some cases, cardiac arrest can occur suddenly and without any noticeable warning, especially if underlying heart problems have not been diagnosed. Regular health checks can help minimize this risk. -

Are older dogs more prone to cardiac arrest?

Older dogs have an increased risk of cardiac arrest because they are more likely to suffer from heart disease. With age, the frequency of veterinary check-ups should therefore be increased. -

What should I do if my dog has cardiac arrest?

If you suspect that your dog has cardiac arrest, start cardiopulmonary resuscitation immediately and take the dog to a veterinarian as quickly as possible. Acting quickly can be crucial to your dog's survival.