Dog heart attack


While canine heart attacks (medical term – myocardial infarction) are rare in the UK, they can occur in dogs of any breed. Sadly in some parts of the USA they are reporting an increase in serious canine heart attacks. This is thought to be due to the increasing amounts of fast food and fatty food consumed by US pets, a reduction in the amount of exercise they take and an increase in pet obesity. Frighteningly many of these pets are also showing an increase in diabetes and atherosclerosis.


What happens in a canine heart attack?

Just as in humans, a heart attack for a dog occurs when the coronary arteries become blocked (or leak) and cut off the flow of blood to the heart muscle. When deprived of blood, the heart does not get sufficient oxygen or nutrients. Therefore, the heart muscle dies, disrupting the heart‘s ability to beat effectively and reducing the heart’s ability to effectively pump blood to their heart and brain.

Additionally, just like humans, dogs can also experience heart health problems, such as heart disease and heart failure.


Helpful research for humans

Furthermore, dogs have served as helpful research models for heart attack studies. Studies on dogs have proven extremely beneficial to diagnosing and treating heart attacks. It was one such study that led to the initially understanding of CPR and another that led to the development of the defibrillator.

Read more on this subject here:


Symptoms of Canine Heart Attacks

Unfortunately, the first recognisable symptom of heart attack is usually collapse. Canine heart attack symptoms can be subtle, so it’s crucial to try and spot early warning signs as this could enable you to prevent your pet from having a fatal attack.

Other symptoms include

  • Vomiting
  • Panting
  • Increased heart rate
  • Fever
  • Pain in front legs
  • Difficulty standing
  • Confusion
  • Immobility
  • Seizure
  • Lethargy
  • Anxiety


Increased risk

A pet with existing heart disease, congenital heart abnormalities or a genetic predisposition will have an increased risk of heart attack. Therefore being able to spot the signs of heart disease is vital


Long-term health conditions can raise risk


Being overweight is a preventable cause of heart attacks in dogs. Carrying extra weight increases your pet’s blood pressure and cholesterol. Certain breeds, such as Basset Hounds, Bulldogs and Beagles can be more susceptible than others.


Diabetes and the resulting high levels of glucose can damage the blood vessels. This in turn can cause heart disease and increase the risk of heart failure.

Bacterial infections

Can sometimes cause a blood flow blockage.


This is when blood vessels become inflamed, this can affect any blood vessels, including those in the heart.


This can slow the heart rate and lead to a rise in blood pressure.


The gradual build up of plaque in the arteries results in restricted blood flow to and from the heart. Atherosclerosis is a main cause of heart attacks in pets and humans.


Canine heart attacks

If you recognize the symptoms of a heart attack in your dog, seek medical attention immediately. 

The severity of a heart attack depends on the extent of the damage to the heart muscle, the location of the infarct and how much of it has been deprived of blood supply.


Collapsed and unconscious?

If your dog has a heart attack that results in collapse and they are unconscious and stop breathing, give CPR if you are confident doing so.

Read our article on performing dog CPR here:

Dog cpr


Physical examination

Your vet will check for signs such as an irregular heart rate or pulse, respiratory distress, jaundice, swelling and dehydration.

Your vet will run tests to make a diagnosis. These may include:

Electrocardiography: an ECG (just like in humans): determines cardiac electrical impulses and detects any abnormal heartbeat rhythms

Echocardiography:can detect heart valve/muscle functioning; and find any fluid or masses in the heart

Blood Culture Biochemistry Profile: tests liver and kidney functioning

Urinalysis: checks kidney and metabolism

Complete Blood Cell Count: assesses red/white blood cell count


Possible treatments

Once the underlying cause of your dog’s heart attack is known, the vet will stabilise your dog’s condition.  Treatment often involves medication.


Your dog may require resuscitation and hospitalization after a heart attack.


Your pet may need medicine to restore their blood flow and remove any blockages.


In some cases surgery may be required to remove these blockages.


If there is accumulated fluid in the dog’s lungs due to congestive cardiac failure, they may be prescribed diuretics (water tablets).


Antibiotics may help mitigate any damage to the heart from infection or inflammation.

Lifestyle changes

You may have to change your dog’s diet and offer supportive care and monitoring at home.


The best way prevent a canine heart attack is to reduce your pet’s risk factors. Keep them at a healthy weight, give them a good diet and ensure they have regular exercise. Pay regular visits to the vet to monitor and stabilize any ongoing health conditions.

Can dogs have heart attacks caused by anxiety?

Studies have shown there is a correlation between anxiety and canine health. Although fear is unlikely to be the main cause it could well be a contributing factor.

Be vigilant

If your dog has been diagnosed with heart issues take extra care and follow the advice from your vet. Heart conditions do mean an increased risk of heart attacks. A heart condition is manageable, but not generally curable so you may need to manage this for the rest of your pet’s life.


First aid for dogs


About us

Written by Emma Hammett for First Aid for Life

Award-winning first aid training tailored to your needs

It is strongly advised that you attend a practical First Aid for Pets course or take our online course to understand what to do in a medical emergency. Please visit,  or call 0208 675 4036 for more information about our courses.

First Aid for Life is a multi-award-winning, fully regulated first aid training provider. Our trainers are highly experienced medical, health and emergency services professionals. They will tailor the training to your needs. Courses for groups or individuals at our venue or yours.

First Aid for Pets provides this information for guidance. It is not in any way a substitute for veterinary advice. The author does not accept any liability or responsibility for any inaccuracies or for any mistreatment or misdiagnosis of any person or animal, however caused.

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