Dogs and Cardiac Arrest

What to Do If Your Dog's Heart Stops

sad dog sick dog
AMR Image/E+/Getty Images

What happens if cardiac arrest occurs in your dog? It’s frightening to think about your dog’s heart stopping suddenly. Although the likelihood of this happening to your dog is relatively low, it’s a good idea to understand cardiac arrest in dogs. Learn what to do if your dog experiences cardiac arrest.

What is Cardiac Arrest in Dogs?

Dogs do not experience "heart attacks" in the same way that humans do.

However, they can experience heart failure that ultimately leads to the heart stopping.

Cardiac arrest (or cardiopulmonary arrest) occurs when the circulatory and respiratory systems cease to function. Simply put, it means that the heart has stopped functioning. A working heart muscle pumps oxygenated blood throughout the body. When the heart stops pumping blood, the body cannot function. Cardiac arrest is a cause of death. 

When a dog experiences cardiac arrest, the process is rapid. The dog will collapse, lose consciousness, and stop breathing (not necessarily in that order). All other bodily functions will rapidly begin to shut down. Unless the dog can be resuscitated within minutes, death will occur. Generally speaking, a dog cannot survive if the brain and other organs are deprived of oxygen for more than about four to six minutes.

Sadly, the chance of successful cardiopulmonary resuscitation after cardiac arrest is low.

Additionally, even if the dog can be resuscitated, continued survival is statistically unlikely. However, the chances of survival often depend on the actual cause of the cardiac arrest.

Causes of Cardiac Arrest in Dogs

There are many different conditions that can lead to cardiac arrest in dogs. Some are medical emergencies that require immediate veterinary attention.

Others are chronic diseases or even dormant conditions. The outcome depends on the severity of the damage to the heart and other organs as well as the advancement of the disease process itself.

Trauma is a common cause of cardiac arrest. Excessive blood loss or injuries to the body can directly impact the heart’s ability to function. Some injuries affect a dog’s ability to breathe properly. Without adequate oxygen supply to the brain, the rest of the body cannot get the signals they need to function. Head trauma can cause damage to the brain that results in cardiac arrest. Dogs suffering cardiac arrest due to trauma may or may not respond to CPR. Some dogs may recover from some types of trauma. Sometimes they need surgery first

Exposure to a toxin can adversely affect many bodily functions that lead to cardiac arrest. Poisonous substances may include plants, foods, chemicals and more. Symptoms depend on the type of toxin and how much was absorbed into the body.

Heartworm disease, if left untreated, will eventually cause cardiac arrest. When the adult heartworms invade the dog’s heart, the organ can no longer properly function.

Anesthetic complications, though uncommon, can lead to cardiac arrest.

Fortunately, most veterinary hospitals use monitoring equipment that will signal problems before the heart is stopped. The veterinary team can take the necessary actions in an attempt to reverse the process and wake up the dog. Though many dogs will survive anesthetic complications, some cannot be resuscitated.

Electrocution can cause the heart to stop suddenly. This is why it's important to keep electrical cords tucked away so dogs cannot chew on them. Chewing electrical cords is especially common in puppies.

Heart disease can lead to heart failure, ultimately causing cardiac arrest. Some forms of heart disease can lie dormant until sudden cardiac arrest occurs. In most cases, dogs develop heart disease that gradually worsens until they suffer from cardiac arrest. Heart disease may be congenital (present at birth) or acquired (developed over time).

There are many different types of heart disease seen in dogs. Senior dogs may develop heart disease. Certain dog breeds are especially prone to various forms of heart disease. Fortunately, many types of heart disease can be managed medically, extending survival times and improving the quality of life in the meantime. 

There are many other diseases and disorders that can lead to cardiac arrest. Any health problem that cannot be cured or treated can have enough impact on the organs and other bodily functions that lead to the heart ultimately stopping.

What to Do If Your Dog Goes Into Cardiac Arrest

It will be very obvious if your dog experiences cardiac arrest. Your dog will lose consciousness and stop breathing. The gums may appear bluish or very pale. The pupils may be dilated. If anything like this happens to your dog, it's important to begin first aid steps as soon as possible. 

First, try to get your dog's attention. If there is no response, check for signs of breathing. Try to hear the heartbeat by placing your ear against the left side of the chest just behind the elbow. Also, you can try to feel a pulse by putting two fingers on the inside of a back leg (in the middle of the inner thigh near the belly). If you cannot detect a heartbeat or pulse, it is likely that the dog's heart has stopped. 

Although CPR is best performed by trained professionals, there is no time to waste. If your dog is not breathing and has no heartbeat, there you cannot really cause more harm by attempting CPR. You will need to breathe into your dog's mouth in between chest compressions. It's a good idea to learn how to properly resuscitate your dog before a situation like this occurs. You may even wish to take a pet first aid class.

If your dog's heart begins to beat again and he is able to breathe, the danger is not over. It is important to get to a veterinarian as soon as possible while keeping yourself safe. Be sure you know where the closest open veterinary office is at all times. Familiarize yourself with the veterinary emergency clinics in your area in case something happens after hours.

Remember, if you think your dog is in cardiac arrest, do not delay. The faster you act, the better your dog's chance of survival. Unfortunately, you need to know that not all dogs can be saved, no matter how skilled the medical team is.