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Dog parents can find themselves in a perplexing situation when trying to identify the specific cause of your dog’s cough. Two of the most commonly confused reasons for a persistent, irritating cough in dogs are congestive heart failure and kennel cough.

While coughing due to dog heart failure sounds similar to the sound of kennel cough, you may have guessed that one is quite a bit more severe than the other. 

Today, we will examine the difference between kennel cough and heart cough as well as dog heart failure sound versus kennel cough sound.

Kennel Cough vs. Congestive Heart Failure

When contemplating dog heart failure sound versus the sound of kennel cough, we must first know what these two very different illnesses entail. First, let’s review kennel cough.

What Is Kennel Cough?

Kennel Cough or Infectious Tracheobronchitis is an all-encompassing term for upper respiratory illness in dogs and is the number one reason for coughing in dogs.

Frequently a dog’s immune system has already been affected by a virus such as:

  • Canine influenza,
  • Adenovirus I or II,
  • Parainfluenza
  • Distemper.

The kennel cough bacteria Bordetella loves to latch on to one of these viruses for a free ride to the upper respiratory system, causing a persistent and prolonged cough.

Kennel cough can spread quickly despite the most valiant sanitation efforts due to its ability to infect through aerosol or droplets in the air.

The kennel cough bacteria, Bordetella, is exceptionally contagious and can be transmitted anywhere dogs hang out. Particularly in enclosed, poorly ventilated places.

Here are the most common ways dogs contract and transmit kennel cough:

  1. Aerosol – from sneezes and saliva
  2. Sharing contaminated water & food bowls
  3. Sharing dog toys & bedding
Causes of Kennel CoughCauses of Heart Failure
Direct contact with an infected dogMitral Valve Insufficiency
Transmission via droplets – airborneDilated Cardiomyopathy
Sharing of contaminated toysEndocarditis (an infection of the heart walls)
Sharing of water and food bowlsFluid around the heart

What Is Congestive Heart Failure In Dogs?

Congestive Heart Failure in Dogs
Congestive heart failure in dogs is a broad term for the heart’s inability to pump sufficient blood to the heart. In the early stages of congestive heart failure, the body will still compensate for the heart’s deficiencies.

As the disease progresses in severity, the mechanisms set to compensate for heart failure will get backed up. 

This causes fluid to build up around the heart, causing what is referred to as congestive heart failure.

What Causes Congestive Heart Failure In Dogs?

There are several possible reasons for heart failure in dogs. The two most common causes are:

  1. Mitral Valve Insufficiency
  2. Dilated cardiomyopathy

Mitral Valve Insufficiency

About 15% of dogs will suffer from heart failure in their lifetime. Of the 15%, most of them are because of mitral valve insufficiency.

What is mitral valve insufficiency, you ask? Let’s talk about the heart for a moment.

The heart has four chambers; each has a one-way valve. Between the left atrium and ventricle is called the mitral valve.

The left ventricle of the heart has a tough job of continually pumping blood out into the body. This hard work also affects the mitral valve, causing it to weaken over time. The weakened valve begins to leak; this is mitral valve insufficiency.

One sign of mitral valve insufficiency is a heart murmur, which results in a persistent cough.

Dilated Cardiomyopathy

Cardiomyopathy is the degeneration of the heart muscle. As the heart degenerates, the muscle tissue becomes thinner and thinner as the left ventricle becomes enlarged. Dilated cardiomyopathy results in a much larger heart, and we don’t mean figuratively.

Dilated cardiomyopathy very common in specific large dog breeds like:

  • Doberman Pinschers
  • Great Danes
  • Saint Bernards
  • Irish Wolfhounds
  • Boxers

Other Causes Of Congestive Heart Failure In Dogs are:

  • Abnormal heart rhythm
  • Fluid around the heart
  • Heartworm disease
  • Defects in heart walls
  • Increased blood pressure
  • Tumors
  • Endocarditis (An infection in the heart walls)
  • Pregnancy

Kennel Cough vs. Heart Cough

Kennel Cough vs Heart Cough in Dogs
It’s easy to understand how a veterinarian could misdiagnose a dog with kennel cough when they are actually experiencing congestive heart failure. It is essential to pay close attention to your dog’s worsening symptoms.

In some cases, the difference between kennel cough and heart cough may be more evident.

Where a kennel cough may be dry, dog heart failure cough may sound wet.

While kennel cough is unproductive, a heart cough may be productive, but these symptoms can be extremely tough to differentiate in reality.

We have created a chart of the symptoms of kennel cough and congestive heart failure below.

Kennel Cough SymptomsCommon in bothHeart Failure Symptoms
Persistent dry coughPersistent wet cough
Difficulty breathingDifficulty breathing
Intolerance to activityIntolerance to activity
Pale gumsPale gums
Pulmonary cracklesPulmonary crackles
Mild feverxHeart rhythm irregularities
Recent onset, quick progressionRecent onset, quick progression
ConjunctivitisxElevated heart rate
Nasal secretionsxAbdominal distention
Loss of appetitexFainting spells
Trachea sensitivityTrachea sensitivity

Dog Heart Disease Cough Sound

Dog Heart Disease Cough Sound
A dog with heart disease or congestive heart failure will result in a cough that sounds like they are trying to cough something up. In many cases, dog heart failure cough sounds very similar to that of kennel cough, except the cough is more productive with heart disease.

Because congestive heart failure often results in the sac around the heart filling with fluid, dogs with heart disease often cough up some foamy matter with their hacking, gagging cough. 

Take a listen to this poor baby who was misdiagnosed and sent home with antibiotics. Luckily his mom paid close attention to the steadily progressing symptoms and caught his illness in the knick of time.

Notice how the sweet boy in the video coughs up foam, breathing exceptionally heavily and panting? You can tell the dog has an increased heart rate due to rapid breathing. These are all tell-tale signs that the dog is experiencing something more serious than kennel cough alone.

The Difference Between Kennel Cough and Heart Cough

Difference between heart cough in dogs and kennel cough
There are several differences between heart disease and kennel cough, but we can’t say the same about kennel cough sound versus dog heart failure cough sound.

The sounds of kennel cough and dog heart disease cough are so similar in sound, especially at the early stages of heart disease, that one can easily be misdiagnosed as the other.

Here are a few differences in symptoms in an attempt to give our readers an inkling of the difference between the two cough sounds.

  1. Dry, hacking, unproductive cough versus wet, hacking, productive cough
  2. Mild fever versus increased heart rate
  3. Flu-like symptoms versus cardiac symptoms

Although kennel cough and heart cough have two incredibly different underlying causes, it is easy to confuse them in the early stages due to their similarities.

Similarities Between Kennel Cough and Heart Failure in Dogs

  1. A harsh, persistent cough
  2. Difficulty breathing
  3. Intolerance to activity
  4. Pale gums
  5. Pulmonary crackles

A Harsh, Persistent cough

This is where it can get challenging to tell the difference between kennel cough and dog heart disease cough.

Check out this video of a beautiful husky with kennel cough. His cough sounds dry and unproductive and ends with a hack or gag like he is trying to expel something.

Similarly, this chihuahua terrier mix suffers from congestive heart failure, yet the cough sounds almost identical.

Difficulty Breathing

With both kennel cough and heart failure in dogs, difficulty breathing may be apparent. Dog heart failure will often cause more extreme labored breathing like this older Shih-Tzu with heart disease.

Intolerance To Activity

Both kennel cough and congestive heart failure result in an aversion to activity due to difficulty breathing and lethargy. Still, heart failure comes with heart rhythm irregularities and an increased heart rate, making the activity more strenuous than it should be for your once vibrant pet.

Pale Gums in Dogs

A healthy doggo should have bubble gum or salmon, pink gums. If a dog has pale gums, it is indicative that something more severe like congestive heart failure.

Pale gums in dogs

If your dog has pale gums, get them to the vet as soon as possible!

Common Reasons For Pale Gums In Dogs:

  1. Anemia
  2. Shock
  3. Blood loss
  4. Kidney disease


Anemia causes a drop in red blood cells, which transport oxygen throughout the body. Other signs of anemia are lethargy, poor appetite, and shortness of breath.


SHock refers to the lack of blood flow through the body; therefore, organs will not receive enough oxygen or nutrition. Shock is often induced by serious trauma, such as a car accident. Shock can be fatal if left untreated, so don’t let this one go.

Blood loss

Blood loss could be caused by parasites or internal bleeding. Get your dog to the vet immediately.

Kidney disease

Renal or kidney disease can be caused by several things, including toxic foods, chemicals, and infection. When the kidneys are not failing, the body doesn’t make as many red blood cells. Less red blood cells mean less oxygen being transported around the body. As you may have guessed, this is a slippery slope. Get to the vet.


Now that we know that heart disease, a severe and often quickly progressing disease, sounds very similar to kennel cough, which is usually relatively mild and self-limiting. We can arm ourselves with information to avoid the doggy disease faux pas.

If your dog has been diagnosed with kennel cough, prescribed antibiotics, and rest, don’t assume your job is done. Remember to keep a close eye on your pet for worsening symptoms, like the cough or signs that don’t quite line up with common kennel cough symptoms.

Your vet is the professional but, you know your pet best. It’s up to you to catch things that the vet may have missed. Trust your intuition if you feel things are not going in the right direction. When it comes to our animals, it’s always better to be overcautious and safe than oblivious and regretful.