Heart Attack in Dogs

What Is a Heart Attack in Dogs?

A heart attack refers to a disruption of blood flow to the coronary arteries, the vessels that give blood to the heart muscle itself. Without blood flow, the heart muscle, known as myocardium, is quickly damaged and the heart is unable to do its job of sending blood throughout the body and organs.

Heart attacks are very rare in dogs, but if your pet is showing any signs of pain, weakness, or trouble breathing, seek veterinary care immediately.

What Is the Difference Between a Heart Attack and Heart Failure in a Dog?

Heart attacks occur if there is a disruption, such as a clot, that blocks the blood supply to the heart muscle. Without blood flow, the heart muscle is unable to contract and provide the needed circulation to the rest of the pet’s body. While a heart attack is possible in dogs, it happens very rarely.

Heart failure is much more common in dogs. The heart functions as a pump to push blood to all parts of the body. Any condition that results in the weakening of the pump—such as degeneration of the heart valves over time, damage from heartworms, or a birth defect of the heart—can result in heart failure.

A dog in heart failure will have fluid build up in either his lungs or his abdomen, depending upon which side of his heart is most affected. Heart failure is also a medical emergency, so any coughing, increase in breathing rate or effort, or swelling in the abdomen should be checked by a veterinarian immediately.

Symptoms of a Heart Attack in Dogs

If your dog is having a heart attack, you may see these signs:

• Loss of consciousness

• Unable to move legs

• Rapid or labored breathing

• Extreme weakness or lethargy (tiredness)

Causes of a Heart Attack in Dogs

In a dog, any condition that increases the chance of too much blood clotting (hypercoagulability) could cause a heart attack. Conditions that can cause hypercoagulability include:

• Diabetes

• Cushing’s disease

• Severe pancreatitis

• Immune-mediated hemolytic anemia (IMHA)

• Sepsis

• Parvovirus

• Heartworm disease

• Cancer

How Veterinarians Diagnose a Heart Attack in Dogs

If a heart attack was a concern, radiographs (X-rays) of the chest, blood pressure measurements, an electrocardiogram (ECG) to check heart rhythm, and an ultrasound of the heart (echocardiogram) may be considered, as well as blood tests to check for infections, organ function, or clotting abnormalities.

Since heart attacks are not common in dogs, baseline tests would typically be started to look for more common and treatable causes.

Treatment of a Heart Attack in Dogs

Ultimately, treatment would depend on the underlying condition that caused the heart muscle to lose blood flow. Prognosis for a true heart attack in a dog is very poor, with most dogs not surviving.

Recovery and Management of a Heart Attack in Dogs

A dog’s chance of recovery from a heart attack is low. It would depend on how much heart muscle was able to continue working and the severity of the underlying condition that was causing clots.

If a heart attack is suspected, veterinary care should be given as soon as possible.