Heart Beating Fast in Dogs

Written By hannah hollinger
Published: 07/24/2017Updated: 08/11/2021
Veterinary reviewed by Dr. Linda Simon, MVB MRCVS
Why is my dog heart beating fast?

What is Heart Beating Fast?

Depending on the size of your dog, a faster heartbeat could be completely normal. Smaller dogs tend to have much faster heartbeats than larger dogs, so it is important to understand what is normal for your particular dog. Tachycardia simply refers to an abnormally quick heartbeat. Besides size, however, there are a few other reasons why your dog may be having a faster heartbeat than usual. This heart issue can be defined a couple of different ways. The first being tachycardia, which means an abnormally fast heart rate. And secondly, arrhythmia, which is the irregular rhythm of a heart. Listed below are a few of the reasons why your dog may be experience a fast heartbeat:

  • Heart disease
  • Drug overdose¬†
  • Congestive heart failure¬†
  • Gastrointestinal disease¬†
  • Ventricular tachycardia¬†
  • Supraventricular tachycardia¬†
  • Stress or anxiety
  • Recent toxin ingestion

If you notice that your dog is having a faster heartbeat than usual, it is vital to get him to a vet as soon as possible. Hearts are very difficult to repair once damage has been done and damage can lead to death if left untreated. So, if you suspect that anything is off, medical attention will be necessary in order to diagnose the issue further. It is always better to be safe than sorry, therefore do not hesitate to get medical help if your dog is showing signs of rapid heartbeat, excessive panting, shortness of breath, lethargy, weak pulse, or fever.

Why Heart Beating Fast Occurs in Dogs

When determining why your dog may have a fast heartbeat, it is important to remember that size does play a part in heart pace. Smaller dogs, even those in perfect health, will have a faster heartbeat than a larger dog. Small dogs and puppies typically have a normal heartbeat of around 120 to 160 beats per minute. Larger dogs, over 30 pounds, tend to have a slower pace at around 60 to 120 beats per minute. If your dog is over the average speed for his weight category, he could be victim to heart disease, drug overdose, congestive heart failure, gastrointestinal disease, ventricular tachycardia, or supraventricular tachycardia. As the first line of defense for your pet, understanding heart issues will help to ensure that you recognize an issue and can act accordingly. Read the descriptions below to learn a bit about what each of these underlying issues are and be sure to speak with your vet immediately if you suspect your dog is suffering from one of them. 

Heart Disease 

Although it is upsetting to hear, heart disease in dogs is actually quite common. There are many reasons why problems in the heart occur and heart failure may occur as a consequence. Monitor your pet closely and if you notice any signs of heart disease such as coughing, lethargy or loss of appetite take your dog to the vet as soon as possible to be examined. 

Drug Overdose 

Toxicity can take place when there is too much of a drug in the bloodstream of a dog at one time. This can happen due to accidental ingestion or by human error. Even if the dog has been specifically prescribed a medicine, too much of it may cause irregular heartbeats or tachycardia. Once this happens the toxicity can either occur very quickly, known as acute, or it can take effect over a long period of time which is known as chronic. Regardless of the speed toxicity occurs, it is vital to get your dog immediate treatment in order to minimize the damage. 

Congestive Heart Failure 

The two most common causes of CHF (congestive heart failure) are mitral valve insufficiency and dilated cardiomyopathy, both of which are a type of valvular insufficiency. While the terms may seem complicated, the definition of CHF is simply that a heart no longer has the ability to adequately move blood throughout the body. It is important to pay close attention to your dog’s behavior. The symptoms that appear with congestive heart failure will depend on which side of the heart is failing. Commonly, dogs will show signs of CHF through coughing, low stamina, loss of appetite, swollen belly, blue gums, or difficulty breathing. If you notice any of these signs paired with a rapid heartbeat, schedule an examination with the vet immediately. 

Gastrointestinal Disease 

While it may not seem that a problem in the digestive tract would affect the heart, the two systems actually share disorders quite commonly. It is a very complicated relationship, however it’s been noted that those with gastrointestinal disease (which can be a blockage and inflammation) can also suffer from cardiac issues as well. This is most likely due to the inflammation that occurs within the digestive tract as a result of damage or blockage, either from food or some foreign body. Monitoring your dog’s behavior is vital if you believe that he has gastrointestinal disease. Catching it early can help prevent any damage from affecting the heart. If you see that your dog has trouble defecating, becomes extremely weak, experiences any abdominal pain, or has blood in the feces, you will want to take your dog to the vet immediately for medical attention.  

Ventricular Tachycardia 

As mentioned previously, tachycardia is defined as an abnormally rapid heart rate. This issue meddles with the rhythm of the heart through its own electrical impulse. 

In order to understand ventricular tachycardia properly, we must first look at the location it takes place inside the heart. Within the heart there are chambers called ventricles which are responsible for pumping blood in and out of the heart and on to the rest of the body. Ventricular tachycardia occurs within these ventricles. Because of the increased heart rate, the ventricles do not have time to fill up completely with blood before the heart contracts; meaning that the blood then does not get pumped through the body correctly. 

Some symptoms that can occur with ventricular tachycardia are:

  • Shortness of breath¬†
  • Dizziness¬†
  • Weakness¬†
  • Chest pain¬†
  • Rapid heartbeat
  • Coughing¬†
  • Collapse¬†

When Ventricular tachycardia occurs, there are some cases where the body can adapt just fine; however, the issue can be life threatening, so it is vital to seek medical attention immediately if you suspect that your dog is suffering from any of these symptoms. 

Supraventricular Tachycardia 

Similar to ventricular tachycardia, supraventricular tachycardia has the same symptoms but occurs in the atria of the heart situated above the ventricles. This issue can occur in both dogs who do and do not have structural heart disease and can be categorized as a type of arrhythmia (irregular heart rhythm). If you notice that your dog is showing any of the symptoms mentioned above, it is vital to see a vet immediately in order to maintain the health and structure of your dog’s heart.

Stress or anxiety 

Stressful events result in cortisol release and a 'fight or flight' response. As well as tachycardia, dogs may pant, hide away and even tremble. This is a temporary response which may occur due to e.g. fireworks overhead or a dog fight. Anything that causes stress will naturally raise the heart beat. This is a normal response and will not cause harm.

Toxin ingestion

Many toxins including nicotine, cocaine and chocolate can all cause the heart to beat faster. Any toxin ingestion requires an immediate vet visit.

What to do if your Dog is Heart Beating Fast

It can be quite alarming to discover that your dog’s heart it beating a bit too fast for comfort. But quite often, it may just be that you’ve never thought about the normal heart rate for your pet. Smaller dogs, under 30 lbs. tend to have a much faster heartbeat than larger dogs, around 120 to 160 beats per minute. Larger dogs over 30 lbs. should have a heartbeat of about 60 to 120 beats per minute. The best way to determine your dog’s heart rate is to follow these steps:

  • Grab a timing device (clock, watch, smartphone)¬†
  • Place your hand over the left side of their chest, just behind the front leg
  • Count the number of beats in 15 seconds, then multiply by four to get the heart rate in bpm (beats per minute)

Because normal heartbeats can vary, it may be difficult to get a correct reading the first time without a baseline. So perform the test a few times before making any assumptions. Measure while your dog is resting or asleep. If what you find is concerning to you, then be sure to set up an appointment for your dog with the vet as soon as possible.

Prevention of Heart Beating Fast

Those predisposed to heart disease should be regularly screened. Unfortunately, there are some cases where heart defects are inevitable. Genetics can pass along a heart problem, so it is worth screening breeding parents. 

The most important thing to remember is that no matter what the cause of your dog’s fast heartbeat may be, getting him to the vet for treatment as soon as possible is the best thing that you can do. Surgery or medications may be able to stop any further damage from occurring so that your pet can live a full life. 

Understand what the normal heartbeat range is for your dog by performing the test mentioned above and do not hesitate to take action if you suspect that anything is amiss.

Cost of Heart Beating Fast

Treatment cost will vary depending on the cause of your dog’s fast heartbeat. For instance, if your dog is diagnosed with congestive heart failure, the average cost of treatment is $2,500. If your dog is diagnosed with rapid heart rate due to ventricular tachycardia, the cost of treatment can range from $500 to $6,500 depending on the cost of living and the severity.

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Heart Beating Fast Questions and Advice from Veterinary Professionals





One Month


8 found this helpful


8 found this helpful

My pet has the following symptoms:
Heart Beating Fast
Why is his heart beating so fast while he just laying there.

Nov. 24, 2020

Answered by Dr. Linda S. MVB MRCVS

8 Recommendations

One month old have natural high heart beats. Up to 200 bpm can be normal. If it seems higher than this or you have other concerns, a vet can check your puppy over.

Nov. 24, 2020

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Shorkie Tzu



14 weeks


12 found this helpful


12 found this helpful

My pet has the following symptoms:
Extremely Fast Heart Rate
My dogs heart is beating extremely fast tonight while she is asleep. It is way faster than it normally is. Should i be concerned

Sept. 29, 2020

Answered by Dr. Michele K. DVM

12 Recommendations

Thank you for your question. Puppies can breathe quickly and have rapid heart rate more than adult dogs, and this may be normal for your puppy. If it is something that is a new problem, or your puppy seems tired more than normal, or is something that is not changing, then it would probably be best to have a veterinarian examine your puppy and assess its cardiovascular system for you. I hope that all goes well with your

Oct. 1, 2020

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