Can Dogs Have Heart Attacks? Causes, Symptoms, and Care

Sudden weakness and labored breathing may be signs of an urgent cardiac crisis in pets.

By Medha deb

Created on Aug 29, 2025

Sudden weakness and labored breathing may be signs of an urgent cardiac crisis in pets.

Can Dogs Have Heart Attacks?

Heart attacks are well-known medical emergencies in humans, but what about our canine companions? While heart attacks in dogs are far less common than in people, they can still occur under certain circumstances. Understanding the causes, signs, diagnosis, and prevention of cardiac emergencies in dogs can help pet owners respond effectively and proactively keep their pets healthy.

What Is a Heart Attack in Dogs?

In medical terms, a heart attackâalso known as a myocardial infarctionâhappens when blood flow to a part of the heart muscle is abruptly blocked, most often due to a blood clot. This loss of blood flow deprives the heart muscle of oxygen, leading to tissue damage or death. In humans, this process is commonly related to cholesterol plaque buildup in the coronary arteries. However, dogs rarely face the same risk factors that humans do, such as high cholesterol and atherosclerosis.

Still, dogs can experience acute blockage of the heart’s blood supply, leading to heart muscle injury. The process typically involves the following:

Blockage in the coronary artery, which supplies oxygenated blood to the heart muscle
Tissue damage resulting from lack of oxygen
Clinical signs that may rapidly progress if not treated

How Common Are Heart Attacks in Dogs?

Heart attacks in dogs are rare. Dogs do not generally develop cholesterol-related plaque as humans do. Instead, canine heart attacks are usually associated with other underlying medical conditions that increase the risk of blood clots or circulation problems. Despite their rarity, it is important for dog owners to be aware of what can cause a heart attack and how to respond if they suspect their pet is in distress.

Causes of Heart Attacks in Dogs

Dogs differ from humans in their predisposition to heart attacks. In most canine cases, a heart attack is the end result of another disease process rather than cholesterol issues. The most common underlying causes include:

Kidney Disease: Severe kidney problems can cause abnormal blood clotting, increasing risk for heart attacks.
Hormonal Imbalances: Conditions such as hypothyroidism can alter blood lipid concentrations and contribute to clot formation.
Vasculitis: Inflammation of blood vessels (vasculitis) can damage vessel walls and lead to blockages.
Heart Tumors or Masses: Growths in or around heart vessels may physically obstruct blood flow.
Bacterial Infections: Severe infections causing sepsis or affecting the heart muscle (endocarditis or myocarditis) may result in clot formation.
Nephrotic Syndrome: A severe kidney disorder that disrupts blood protein levels and contributes to clotting.
Congenital Heart Defects: Some dogs are born with abnormalities that increase heart disease risk and, rarely, heart attack.

While anxiety and stress are not direct causes, they can worsen pre-existing heart conditions in susceptible dogs.

Heart Attack vs. Heart Failure

A heart attack (myocardial infarction) is different from congestive heart failure. Heart failure is a progressive weakening of the heart’s pumping ability, leading to fluid buildup in the lungs and body. Heart attacks are sudden events typically related to a blood clot or vessel blockage, while heart failure develops more slowly due to chronic heart disease or age-related degeneration.

Heart Attack (Myocardial Infarction)	Heart Failure (CHF)
Acute, sudden onset due to blocked blood flow	Chronic, slow progression due to weakened heart muscle
Typically caused by blood clot, vessel damage, or rarely, abnormal cholesterol	Often caused by valve disease, heart muscle disease (cardiomyopathy), congenital defects, or prolonged high blood pressure
Presents with collapse, pain, or acute distress	Presents with cough, exercise intolerance, fluid retention, rapid breathing

Symptoms of Heart Attack in Dogs

Because canine heart attacks are so rare, their symptoms can be mistaken for other severe medical emergencies. Watch for the following signs, especially in dogs with existing heart or kidney problems:

Sudden weakness or collapse
Extreme lethargy or inability to move
Rapid or irregular heartbeat
Difficulty breathing, heavy panting, or gasping
Vomiting or retching
Pain, especially in the chest or front legs
Confusion, disorientation, or unresponsiveness
Pale or bluish gums and tongue, indicating poor oxygen circulation

Symptoms may be subtle in some dogs, while in others the onset is dramatic and sudden. Immediate veterinary attention is required for any of these signs, even if not caused by a heart attack.

Symptoms of Congestive Heart Failure in Dogs

Coughing, often at night or after exercise
Difficulty or labored breathing
Increased respiratory rate even at rest
Persistent fatigue or reluctance to exercise
Distended abdomen due to fluid buildup
Fainting or loss of consciousness

How Are Heart Attacks in Dogs Diagnosed?

Diagnosing a heart attack in dogs can be challenging. Many symptoms overlap with other serious illnesses. Veterinarians use a careful blend of physical examination, imaging, laboratory work, and advanced tests to reach a diagnosis. The process usually includes:

Physical Examination: The vet will assess vital signs, listen to the heart and lungs, and look for signs of shock or distress.
Blood Tests: Evaluate organ function, look for infection, thyroid imbalances, kidney issues, and markers that might indicate heart muscle damage.
Electrocardiogram (ECG): Measures the heartâs electrical activity, detecting arrhythmias, conduction disturbances, or heart muscle damage.
X-rays (Radiographs): Help identify an enlarged heart, fluid in the lungs or abdomen, or masses near the heart.
Echocardiogram (Cardiac Ultrasound): Visualizes the structure and function of the heart, measures blood flow, and may detect blood clots, tumors, or areas of weakened muscle.
Other Tests: Based on findings, further imaging (like CT or MRI) or infectious disease screening may be recommended.

Treatment of Heart Attacks in Dogs

Immediate veterinary attention is essential if a heart attack is suspected. Treatment aims to restore blood flow, stabilize the dog, and address any underlying conditions. Key aspects of treatment may include:

Resuscitation: Emergency measures, such as oxygen therapy, intravenous fluids, or even CPR if cardiac arrest has occurred.
Blood Thinners: Medications to prevent further clot formation and help dissolve existing blood clots.
Anti-arrhythmic Drugs: Used to stabilize abnormal heart rhythms.
Ongoing Medications: Therapy targeting underlying conditions, such as thyroid hormone for hypothyroidism or antibiotics if an infection is present.
Surgical Intervention: Rarely, surgery may be necessary to remove a tumor or clot contributing to the blockage.
Pacemaker Implantation: In certain cases, a pacemaker may be implanted if the dogâs heart rhythm canât be stabilized with medication.

Recovery depends on the underlying cause, the promptness of treatment, and the overall health of the dog. Some pets may require long-term medication and monitoring for the remainder of their lives.

Treatment of Congestive Heart Failure in Dogs

CHF requires ongoing management with one or more medications:

Diuretics (e.g., furosemide): Remove excess fluid from the body.
ACE inhibitors (e.g., enalapril): Relax blood vessels and ease the heart’s workload.
Positive inotropes (e.g., pimobendan): Strengthen the heart muscleâs contractions.
Vasodilators: Help widen blood vessels.
Other drugs: Depending on the underlying problem, additional medications and dietary modifications may be prescribed.

Frequent check-ups, lab work, and lifestyle adjustments are critical for managing chronic heart conditions.

Can Heart Attacks in Dogs Be Prevented?

Since most dog heart attacks are secondary to other illnesses, prevention focuses on minimizing underlying risk factors wherever possible. Steps every dog owner can take include:

Weight Management: Keep your dog at a healthy weight; obesity increases stress on the heart.
Balanced Diet: Feed your pet a nutritionally balanced food appropriate for age, activity, and medical history.
Regular Exercise: Provide daily exercise suited to your dogâs breed, size, and health status.
Routine Veterinary Care: Annual or biannual vet exams can help catch health problems early.
Monitor Chronic Diseases: Strictly manage conditions like kidney disease, thyroid issues, and high blood pressure as advised by your veterinarian.
Dental Health: Address dental disease, since oral infections can negatively impact heart health.
Minimize Stress: Create a calm environment, particularly for senior dogs or those with heart disease.

For dogs diagnosed with heart or kidney conditions, follow your veterinarianâs management plan closely and report any changes in behavior or activity right away.

Frequently Asked Questions (FAQs)

Are some breeds more predisposed to heart attacks?

Certain breeds are more prone to chronic heart disease, which can increase risk. These include Cavalier King Charles Spaniels (mitral valve disease), Doberman Pinschers (dilated cardiomyopathy), and Boxers. However, heart attacks from coronary artery disease are rare in all breeds.

What should I do if I think my dog is having a heart attack?

Contact your veterinarian or an emergency animal hospital immediately. Do not attempt to treat your dog at home. Emergency measures may include oxygen therapy, medications, and advanced monitoring.

Can anxiety or stress cause a heart attack in dogs?

While acute stress may worsen heart symptoms, it is not a common direct cause of heart attacks in dogs. Prolonged stress can, however, contribute to heart problems in pets with underlying disease.

Is heart failure the same as a heart attack in dogs?

No. Heart failure is a gradual weakening or inefficiency in the heart’s ability to pump blood, usually from progressive heart disease. A heart attack is a sudden event caused by a blocked artery limiting blood flow to the heart muscle.

How long can a dog live after a heart attack?

Survival depends on the cause, severity, and treatment. Some dogs may resume a good quality of life after emergency management, but many will need ongoing care for chronic heart problems.

Key Takeaways for Dog Owners

Heart attacks in dogs are rare and usually linked to underlying illnesses rather than cholesterol plaque.
Symptoms can be subtle or sudden, including weakness, collapse, abnormal breathing, and confusion.
Prompt veterinary diagnosis and treatment are essential for the best outcome.
Ongoing management and lifestyle modifications play an important role in preventing and controlling heart problems.
Regular check-ups and early intervention give your dog the best chance at a long and healthy life.

Resources for Further Reading

American Kennel Club Canine Health Library
Veterinary Cardiology Specialists
Your primary care veterinarian

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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