Cardiovascular diseases

5 Symptoms of Congestive Heart Failure in Dogs

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. January 29, 2020
5 Symptoms of Congestive Heart Failure in Dogs

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It can be too easy to take the heart for granted. Its functioning is necessary for life, but its involuntary action means we don't have to consciously control it. This is why heart disease is described as the ‘silent killer’. When it comes to our own health, the symptoms can be very difficult to recognize. Unfortunately, too many of us only know about heart murmurs and congestive heart failure when it is too late. For dogs, their inability to communicate verbally makes our awareness of their heart problems even more difficult to detect.

This is why AnimalWised brings you the main 5 symptoms of congestive heart failure in dogs. While some of these symptoms may be attributable to other conditions of varying acuteness, none of them should be ignored.

You may also be interested in: Heart Failure in Cats
  1. Heart failure in dogs
  2. Arrhythmia
  3. Respiratory problems
  4. Intolerance to exercise
  5. Vomiting
  6. Weakness and lethargy
  7. What to do if your dog is suffering from one of the 5 symptoms of congestive heart disease in dogs

Heart failure in dogs

Since heart disease can be difficult to register, we need to look at the main symptoms of heart disease in dogs. They are:

  1. Arrhythmia
  2. Respiratory problems
  3. Exercise intolerance
  4. Vomiting
  5. Weakness and lethargy

There are various reasons a dog's otherwise healthy heart may suffer from cardiac failure. These may be due to the dog's lifestyle, an infection, parasites, physical trauma or even stress. These can lead to congestive heart failure, i.e. the heart cannot function properly either due to blockages or due to the condition of arteries and blood vessels. This means blood cannot be pumped adequately around the body, resulting in various physiological and behavioral symptoms.

However, not all congestive heart failure in dogs is due to external factors. Congenital heart disease is a type of heart failure whereby the damage to the heart is related to genetic issues. Certain breeds are more likely to develop heart disease due to the breeding programs which have resulted in the breed standard.

For example, brachycephalic breeds such as Bulldogs and Pugs are more likely to develop heart disease. This is because their morphology leads to upper respiratory problems, over time causing a ‘remodelling’ of the heart which results in congestive heart failure[1].

Commonly, the causes of heart failure in dogs will be a combination of factors. If a dog is prone to obesity, their diet and exercise regimen will influence their likelihood to develop congestive heart failure. Maintaining health through diet and exercise is not the only influence on a dog's heart health. One study has shown that oxidative stress can be affected by the sex and neuter status of the dog as well as serum cholesterol concentration[2].

Many of the symptoms of heart disease are shared by other diseases affecting dogs. For this reason, taking your dog to the veterinarian to carry out the appropriate diagnostic tests is vital. So too is maintaining regular checkups so any developing problems can be addressed as early as possible.

1. Arrhythmia

While other symptoms of congestive heart failure in dogs may also be present in other health conditions, arrhythmia is a definitive sign that the heart is affected. The underlying cause may not be a heart problem, but the disease has now impaired the heart's ability to pump blood around the body.

An arrhythmia is an irregular heartbeat. This may be temporary, meaning the problem may not affect the long-term health of the dog. However, consistent or chronic arrhythmia can lead to fatal heart failure. There are different types of arrhythmia, some of which can be either too fast or too slow. Determining the root cause of the heart murmur will require a clinical diagnosis.

5 Symptoms of Congestive Heart Failure in Dogs - 1. Arrhythmia

2. Respiratory problems

It is not always easy to detect arrhythmia, especially if we don't know to look for it. The dog may otherwise be completely asymptomatic, despite the heart slowly being damaged inside their chest. One of the more noticeable symptoms in dogs with heart failure is a respiratory problem. We can see when they are breathing fast and shallow, make choking noises or otherwise draw attention to their breath. In dogs with heart disease they may suffer:

  • Fast breathing
  • Difficult inhaling
  • Coughing
  • Frequent panting
  • Congested sounds

Any of these symptoms may indicate cardiovascular problems in the dog, but they may also be related to another condition. Frequent coughing is also a common indicator. However, we also need to look at the context in which the respiratory changes appear. If the dog has just finished exercise or it is a hot day, their breathing may change without implying a long-term health problem.

3. Intolerance to exercise

Dogs with heart problems suffer from discomfort and weakness when doing intensive exercise. The worse the congestive heart issues, the less exercise it may take to tire them out. Certain breeds may also have more difficulty exercising due to their physical characteristics, often those which are more likely to suffer from heart failure. You will know your dog has an intolerance to exercise if:

  • They faint easily after physical exertion
  • They pant excessively when walking
  • They are more prone to heatstroke
  • They refuse to do exercise

These are warning signs that the dog is having physical trouble, often related to their heart health. A healthy dog which is used to an active routine with moderate exercise should not display an intolerance to exercise.

4. Vomiting

If arrhythmia is a symptom which is directly related to heart problems, vomiting is something which is much more widespread. It is most commonly related to gastrointestinal disorders, but there are many reasons a dog may vomit. Heart disease is one such reason a dog may regurgitated some bile due to heart issues. It may be more common after exercise.

5. Weakness and lethargy

The final of our 5 symptoms of congestive heart failure in dogs is weakness, lethargy and apathy. It is not that your dog doesn't want to get up and exercise. The problem is that their heart malfunctioning causes the other systems in their body to be affected. They do not have the energy for physical exercise because not enough oxygen is going to the cells where it needs to go. This can be very discomfiting for the dog.

Depression is a psychological reason why your dog may become apathetic and appear weak. However, even if this is the case, it can only be determined after a physical problem has been ruled out. For this reason, if your dog appears apathetic for no reason, we need to take them to the veterinarian immediately.

5 Symptoms of Congestive Heart Failure in Dogs - 5. Weakness and lethargy

What to do if your dog is suffering from one of the 5 symptoms of congestive heart disease in dogs

Congestive heart failure is an umbrella term for various heart problems which can affect your dog. Among them are dilated and hypertrophic cardiomyopathy, and valvular heart disease. Cardiomyopathy refers to any disease which affects the heart as a muscle and valvular heart disease relates specifically to the heart's valve function.

In order to find out which type of congestive heart failure is affecting your dog, or whether the problem may be related to some other health condition, the veterinarian will need to carry out various diagnostic tests. These will include a blood test, electrocardiogram, ultrasound and, potentially, a chest x-ray. This will be after the veterinarian carries out a physical examination.

Based on the diagnosis, the veterinarian will prescribe a specific treatment. For hypertension, it is possible medication will be prescribed, but it is likely the dog will require dietary changes also. In more serious cases, they may recommend surgical intervention.

We need to point out that, while it can affect dogs of any age, senior dogs are more susceptible to heart failure. If your dog is considered to be in old age, it is important we both observe them closely for any changes to their behavior. Veterinary visits should also be carried out more regularly.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to 5 Symptoms of Congestive Heart Failure in Dogs, we recommend you visit our Cardiovascular diseases category.


1. Canola, R. A. M, et al. (2018). Cardiorespiratory Evaluation of Brachycephalic Syndrome in Dogs. Pesq. Vet. Bras., 38(6), 1130-1136.

2. Reimann, M. J., et al. (2017). Markers of Oxidative Stress in Dogs with Myxomatous Mitral Valve Disease are Influenced by Sex, Neuter Status, and Serum Cholesterol Concentration. Journal of Veterinary Internal Medicine, 31(2), 295-302.

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5 Symptoms of Congestive Heart Failure in Dogs