Congestive Heart Failure In Dogs – When to Put Down?

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Author: Jacob Kay

As a dog owner, you wish your dog lives a long and healthy life. We try and provide the perfect lifestyle to increase their life expectancy. But, there is always a risk of them developing a fatal illness such as heart disease. This type of illness imbalances their lifestyle and reduces their life years.

Generally, dogs are either born with such conditions, or gradually develop them while growing up. The dog’s age, health issues or infection, results in such heart disease. Now, if the condition elevates further, it leads to congestive heart failure in dogs.

Congestive Heart Failure In Dogs

Congestive heart failure condition i.e. CHF has basically two forms of failure. One is left-sided and the other one is right-sided. In this condition, a dog’s heart finds it difficult to pump the blood for its body. So, there is a rise in pressure and fluid which ultimately leaks into the lungs and at times into other major organs.

Once the fluid gets into the dog’s lungs, the normal expansion is prevented. The flow of oxygen into the bloodstream is also not proper and it causes different health issues. Now, let’s get into the details of both the sides of failure condition:

  • Left-sided congestive heart failure

The left-side failure drives the pressure to back up in the vessels which pump the blood into the left ventricle of the heart. Then the blood leaks through the mitral valve causing excess fluid to become clogged in the lungs.

Further, the fluid gets into the lungs of the dog and they will suffer from coughing, difficulty, exercise intolerance, and high respiratory rate.

  • Right-sided congestive heart failure

Here the pressure is exerted into the vessels where the blood flows into the right atrium from the veins into the body. Instead of leaking through the mitral valve, blood leaks where it is pumped into the heart and is jammed within the body.

Now, this pressure can further, lead to fluid buildup in the chest cavity, abdomen, liver, and even the limbs. The pressure around the lungs causes breathing difficult for the dog.

Lastly, if both ventricles are not working properly there is a biventricular failure.

Symptoms of Congestive Heart Failure dogs

The signs of CHF in dogs vary as per the size of the heart. The common signs are difficulty in breathing, a distended abdomen and swollen limbs. Here are some other signs that you need to know:

  • Difficulty breathing / shortness of breath
  • Fainting
  • Swollen belly (because of fluid buildup)
  • Inability to exercise
  • Persistent coughing
  • Fatigue
  • Pacing before bedtime and difficulty settling down
  • Lack of appetite
  • Weight loss
  • Change in gum and/or tongue colour to a bluish-grey ( poor oxygen flow)
  • Elevated heart rate
  • Crackling sound when listening to the lungs

If you observe these symptoms, it’s best you take your dog to the vet for proper treatment.

Congestive Heart Failure in Dogs stages

There are different stages of congestive heart failure. Each of these stages suggests an approximate level of damage that you can expect in your dog’s heart.

  • Stage A

Here, the dog is only at risk of having heart disease. This means that there are no definite symptoms or clinical signs indicating the issue. However, at this stage, the condition of the heart does begin to deteriorate a bit. This stage can last for years, and if it’s not progressive there is a minor chance of improving the condition.

  • Stage B and Stage B2

At stage B, there is a heart murmur i.e. unusual sound in the dog’s heartbeat, heard using a stethoscope, but, no clear indication of heart failure. But, in stage B2, the dog has a detectable heart murmur but, not showing clinical signs. Although, there are some structural changes in their heart. These changes are visible with the help of an X-ray or electrocardiogram.

  • Stage C

At this stage, you will observe various symptoms. The dog will suffer from fatigue, coughing, shortness of breath and so on. The heart is not pumping properly, and the collection of fluid in the chest area will cause breathing issues. Here, the dog will respond to the medications.

  • Stage D

This stage is also referred to as the end stage i.e. a dog is suffering from complete CHF. This means the chances of the dog surviving are very low. The swelling in the belly region is unbearable and even at rest dog will feel the pain. Walking is difficult because there is swelling in the legs as well. The symptoms are severe and the dog is barely responding to any medication or treatment.

Causes Of Congestive Heart Failure In Dogs

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There are many factors that can cause CHF in dogs. In fact, some fogs are just born with congenital heart conditions which result in congestive heart failure. It is rare, but, this condition constitutes roughly 5% of heart disease in dogs. Now, let’s have a look at the causes in detail:

#1 Mitral Valve Insufficiency

According to Jerry Klein, DVM and Chief Veterinary Officer of the American Kennel Club, MVI is one of the major causes of CHF in dogs. Roughly, 80 per cent of congestive heart failure cases happen because of Mitral Valve Insufficiency. The MVI happens when there is a leak in the valve that connects the left atrium and left ventricle. So, if there is no proper treatment, the condition can worsen and damage both sides.

#2 Cardiomyopathy

This condition occurs when the dog’s heart muscles degenerate and loses their ability to contract, making the heart a weak pump. The blood will flow slower and hence, a low blood pressure. In addition, dilated cardiomyopathy often leads to biventricular failure.

#3 Abnormal heartbeats

The abnormal heartbeats basically refer to arrhythmia. Here an abnormal heartbeat can cause damage to the muscle and blood vessels. When this issue is left untreated, it causes congestive heart failure. Apart from the above-mentioned causes, there are some others as well:

  • Narrowing of primary blood cells
  • Heartworms
  • Narrow blood vessels
  • Bacterial infections
  • Parvovirus
  • Hypothyroidism
  • Nutritional deficiency
  • Fluid accumulation around the heart
  • Tumours or cancer

Diagnosis for CHF

Diagnosis for congestive heart disease will require a vet to conduct some tests. You will have to provide the entire medical history of your dog for an accurate diagnosis.

  • Blood and urine tests– for determining issues in the liver and kidneys. Dogs suffering from heart disease have problems in their kidneys or liver.
  • Chest X-rays – these reports help in outlining the size and shape of the dog’s heart. In addition, if there is fluid present within the lungs is also detected.
  • EKG – Electrocardiogram helps in identifying anomalies in heart rate and rhythm.
  • Echocardiogram (Ultrasound) – will monitor the size, shape, and movement of the heart. It can easily help a cardiologist determine whether the heart of the dog is pumping properly or not.
  • Heartworm antigen test – will look for abnormal proteins that heartworms produce. So, if the screening suggests that the dog is heartworm-positive, proper treatment can be carried out.

Treatment for congestive heart failure

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Treatment for congestive heart failure completely relies on the underlying heart disease, along with the severity. Generally, there is no cure for CHF, but there are some effective treatments for ensuring a good quality of life for the dog.

So, if the cause of CHF is a congenital abnormality such as a PDA, surgical correction may help to reverse heart failure if done on time. The main aim while treating CHF is to lower fluid buildup and maximise the amount of blood that is pumped to the lungs and the rest of the dog’s body.

  • ACE inhibitors

Angiotensin-converting-enzyme inhibitors such as enalapril, captopril, and benazepril can help lessen blood pressure and volume, reduce stress on the heart, and slow down the degeneration of the heart muscles.

  • Vasodilators and positive inotropic drugs

vasodilators will reduce the pressure on the heart and help in relaxing the blood vessels. As a result, the heart can pump blood with ease. The positive inotropic drugs will elevate the force with which the heart pumps. The heart can now pump more blood to the lungs and the remaining parts of the body.

  • Diuretics

Diuretics like Furosemide are useful in treating fatal conditions such as Congestive Heart Failure. This loop diuretic will stimulate the kidney and deal with the excessive fluids or urine present in the body. It will remove the excessive amount of fluid from the lungs as well. Hence, the workload of the heart is reduced and it can function better.

  • Nutrition

Controlling the level of sodium can help reduce the fluid in the dog’s body. Also, supplements such as taurine, vitamin B, carnitine, and Vitamin E, and antioxidants like coenzyme Q10 will also help in reducing fluid buildup.

If the treatment is at home, follow-up appointments with a vet are a must. These checkups will help determine whether there is any improvement or not.

Dog Enlarged Heart When To Euthanasia?

When the dog is diagnosed with Congestive Heart Failure condition, the heart is already enlarged and no treatment or medication can help them recover from such a condition. The dog is in agony and vets will suggest euthanasia.

Euthanasia is referred to putting an end to a dog’s life. This helps in freeing them from the pain and agony they suffer from different fatal health conditions such as tumours or in this case, heart failure. The CHF condition is not curable and euthanising is probably a good decision one can make for their furry friend.

The quality of life of the dog is already low and no treatment is going to help them recover. In fact, these treatments also cause different pain and reaction. So, you need to make the decision of whether you need to proceed with the treatment or put your dog to sleep. Here are some signs that will help you make take the decision.

  • Difficulty in breathing even when oxygen supplements are given
  • Seizures
  • Loss of appetite
  • Blue gums
  • Distended abdomen

So, when these symptoms or signs elevate, the dogs can barely remain conscious or show any energy. It’s best you consult with the vet on the situation and when to put them down and relieve them of such misery.

You can expect the vet to follow a basic protocol for euthanising the dog. Here are the common steps they might use:

  1. Use the sedative to calm and relax the dog.
  2. Inject the euthanasia drug into the dog’s system.

Once the drug is inside the dog’s system, it will stop the brain and heart function.

Now, before we conclude the article, let’s get a quick insight into a common query – Can dogs have heart attacks?

Can dogs have heart attacks?

Yes, dogs can have heart attacks. The chances of dogs having heart attacks are less but, if they do happen, it’s quite fatal. In fact, a sudden heart attack can even cause the instant death of the dog.

The reason for such heart attacks mainly involves issues such as- high blood pressure, obesity, diabetes, or a serious bacterial infection. So, if you feel your dog is having a heart attack you need to take them to the nearest emergency room.

You can try reviving the dog with CPR, but, it won’t work as the technique is different in dogs and mandates special training. Still, if you try CPR, you may worsen their condition and cause injuries as well.


How much will a dog with heart failure live?

If there is heart failure in dogs, especially congestive heart failure, you can expect a dog to live a minimum of 6 months and a maximum of 2 years. The life span depends on the timing of the diagnosis and the treatment carried out. For instance, if the diagnosis was in stage D i.e. the end-stage then the dog will die sooner.

What happens at end stage heart failure in dogs?

In the end stage of heart failure, the breathing activity for the dog gets tough. They find it difficult to breathe even while resting. The fluid starts to accumulate in different areas of the body. This results in swelling of the legs, abdomen, and also health issues such as vomiting.

Which dogs risk having CHF?

Normally, small breeds have shown a genetic proneness towards CHF. Pomeranians, Dachshunds, and Toy Poodles are a few examples. The reason why large breed dogs are not prone is that the heart valves in small dogs tend to degenerate more.

Can a dog recover from an enlarged heart?

An enlarged heart is referred to as dilated cardiomyopathy and is manageable if not progressive. There are plenty of medications that can elevate the heart’s pumping capacity and handle arrhythmias. In addition, a diuretic is also used for reducing fluid accumulation in different tissues. And a vasodilator is also given to improve blood circulation and blood vessels.


Congestive heart failure is common and many senior dogs have this health issue. There is no cure for this condition. The next best thing for such situations is extending the dog’s life span without compromising its quality of life. Because it’s difficult to precisely outline the timeframe of survival. As per the vets, the best bet is 6 months, 1 year or a maximum of two years.

So, regardless of the prognosis, as a dog owner, you can help them live a happy life by providing a good diet, mild exercise (if the dog can), giving regular medication, and spending more time.

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Jacob Kay
Jacob Kay is a Veterinary Advisor and Editor at WWD. He’s also a dog lover and has two pet dogs of his own. He has extensive knowledge in the field of veterinary medicine and is always happy to share his insights with others.

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