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Signs, Causes, and Treatments of Heart Disease in Dogs

Heart disease is a term that is used to describe many different conditions that affect the heart.

Unfortunately, heart disease is common in dogs just as it is in humans. And like humans, canine heart disease does not disappear but worsens with time. If the situation isn't handled promptly, your dog’s risk of death from cardiovascular disease in greatly increased.

Canine heart disease encompasses many conditions, including myocardial disease and chronic valvular disease.

Myocardial disease is characterized by heart muscle weakness, which impacts the heart's pumping ability.

On the other hand, chronic valvular disease involves a leaking heart valve, thus reducing the quantity of blood pumped around the body.

This post looks at the signs, causes, and treatment of heart disease in dogs.

Signs of Heart Disease in Dogs

Although there are several different conditions that constitute heart disease in dogs, below are some common symptoms which may indicate that your pet is experiencing cardiovascular issues:

Persistent Cough

Persistent coughing is one symptom of heart disease in dogs. We're not talking about a cough that lasts one or two days—we mean a cough that continues for at least one or two weeks.

One explanation for why dogs with heart disease cough is that fluid can accumulate in the lungs when the heart isn't pumping efficiently. Another explanation could be enlargement of the heart which results in pressure on the airways.

Canine coughs can be caused by a number of things, including allergies, asthma, etc., so you shouldn't automatically assume any cough is a sign of heart disease. The best thing is to have your dog checked by a veterinarian.

Pacing and Restlessness

Your dog may become distressed when they are unwell. Dogs are likely to pace due to pain from heart failure or become distressed due to the secondary symptoms associated with heart failure, like excessive panting, coughing when at rest, swollen legs or belly, vomiting, etc.

Dogs can also become restless when they feel something is wrong. Like in humans, heart disease may cause your dog to feel anxious as their condition worsens, even though they don't realize exactly what is happening in their body.

Difficulty Breathing

Your dog is likely to experience breathing difficulties as heart disease progresses. You may notice that your dog is breathing more rapidly or is struggling to breathe, and sometimes you may hear your dog wheezing when sleeping or resting.

Dogs who are experiencing breathing troubles have difficulty lying down and often stand for long periods of time with their mouth wide open.

Of course, many other health issues, such as asthma, pneumonia, canine influenza, etc., can cause your dog to have a difficult time breathing, so it's best to have a veterinarian check your pet if you notice this issue.

Fainting or Collapse

Another sign of heart disease in dogs is fainting or collapsing. This usually happens when heart function is not optimal and vital body organs such as the brain don't get enough oxygen and other vital nutrients.

In other words, dogs with heart disease can experience compromised blood flow to the brain, leading to weakness or collapse.

If you're unsure what has caused fainting in your dog, take them to the vet immediately so they can assess your dog and determine what the problem is.

Lethargy and Weakness

Lethargy and weakness are other signs of heart disease in dogs. Of course, these signs can be due to other health issues as well, but heart disease could be the culprit if your dog shows these signs alongside other symptoms in this list.

Lethargy and weakness are common experiences as heart disease progresses in dogs. Consult your vet on how to control the symptoms to make your pet comfortable and live a normal life.

Less Active/Inability to Exercise

Dogs with heart disease will be less tolerant to exercise. As such, you may realize that your dog gets tired quickly during walks or other routine exercises or is sleeping or resting more than usual.

There are many things that cause these signs in your dog, so if the issue persists make sure to have your dog checked by a qualified vet to determine if heart disease could be the cause.

Heart Murmur

A heart murmur occurs when there's a disturbance in the blood flow within the heart. Fortunately, not all murmurs are a cause for alarm. For example, puppies can have 'innocent' or ‘physiologic' murmurs that pose no threat to their health.

However, a heart murmur in adult dogs can indicate an underlying health issue. It can either be due to heart disease (pathologic) or not due to heart disease (extracardiac).

Not all murmurs sound the same, so it's best to have your dog examined by a vet to determine their type of murmur.

Swollen Abdomen

A dog may have abdominal swelling in the later stages of heart disease. In most cases, this is due to fluid buildup that is the result of the weakening of the heart.

A swollen abdomen due to heart disease usually indicates that your dog is in the last stages of heart failure. The condition may cause a lot of discomfort and pain to your pet.

Loss of Appetite and Sudden Weight Loss

If your dog won't eat even after offering them their favorite food, it's a sign that they're unwell. This could include having a heart problem. Sudden weight loss could also be a sign of heart disease in dogs. Consult your vet if your pet won't eat or has shown signs of weight loss so they can determine what might be causing the problem.

Causes of Heart Disease in Dogs

To better understand the causes of heart disease in dogs, let's look at the two categories of heart disease in dogs: congenital heart disease and acquired heart disease.

Congenital Heart Diseases in Dogs

Congenital heart disease is related to genetics. In other words, dogs with congenital heart disease are born with this condition. Your dog may inherit the problem or simply be born with the condition.

Unless your dog shows symptoms of heart disease or is diagnosed by a vet during routine vet visits, it can be hard to tell if or when your dog will fall ill.

Regular exercise, a healthy diet, and overall pet care can delay the onset of congenital heart disease.

Common types of congenital heart disease in dogs include:

  • Congestive Heart Failure. This condition affects the flow of blood in the heart. It can also cause fluid and pressure buildup within the heart.
  • Pulmonic Stenosis. This heart condition results from the narrowing of the valve between the lung arteries and the lower right heart chamber, which interferes with blood flow from the right ventricle to the pulmonary artery.
  • Canine Dilated Cardiomyopathy. This disease affects the cardiac muscle, reducing the heart's ability to pump blood.

Acquired Heart Disease in Dogs

Not all heart diseases are congenital. Acquired conditions develop over time in middle-aged and senior dogs due to normal wear and tear, diet, level of physical activity, and aging.

While there are several different heart conditions that can affect your dog, they usually present similar symptoms. However, since the causes are different, management and treatment are different.

Common acquired heart conditions in dogs include:

  • Canine Valvular Disease. This disease is more common in smaller dog breeds. It is caused by the thickening or breakdown of the heart valves.
  • Pericardial disease. This disease is due to the accumulation of excess fluid within the pericardial sac, which reduces the heart's ability to pump effectively.
  • This condition occurs when the impulses that regulate how the heart beats are affected, resulting in an irregular heart rhythm. Common causes of arrhythmia in dogs include diabetes, cardiomyopathy, drug misuse, high blood pressure, and heart valve disease.

Some infections, such as heartworm, viruses, and bacteria, can also lead to heart diseases such as endocarditis and heartworm disease.

Treatment of Heart Disease in Dogs

Heart disease in dogs can be treated or managed using prescribed medications, dietary adjustments, supplements, and, in severe cases, surgery.

However, since heart disease is a general term referring to conditions that interfere with normal heart functions, the exact treatments depend on your dog's specific problem and the cause. Below are the possible treatment options:


Your vet may prescribe Digoxin Tablets if your dog has congestive heart failure. These tablets can help improve the heart's ability to beat, giving your dog a more normal heartrate.


Narrowing of the blood vessels carrying blood to and from the heart can also lead to congestive heart failure. In such a case, your vet may prescribe VETMEDIN to treat your dog.

Vetmedin Chewable Tablets for Dogs are FDA-approved for treating and managing Congestive Heart Failure in dogs (mild, moderate, and severe cases). They help open the blood vessels to improve the heart's pumping ability.


Like VETMEDIN, Enalapril can help open up the blood vessels and reduce fluid retention in the body. Your vet may prescribe Enalapril to treat heart failure and high blood pressure.


For dogs with heart failure disease and high blood pressure, your vet may prescribe Benazepril HCL Tablets. This treatment blocks angiotensin, a natural enzyme involved in narrowing blood vessels.


Furosemide is a diuretic that a vet may prescribe to remove excess bodily fluid (edema) due to heart failure, kidney disease, and liver disease. Options include Furosemide Tablets, Furosemide 10mg/ml Oral Solution 60 ml, and Salix (Furosemide) Tablets.

Other tablets that your vet may prescribe to treat heart disease in dogs include:

Besides medication, the type of food you give your dog will affect their heart health and overall health. Diets such as Hills Heart Care h/d Dry Dog Food is a balanced diet that can support heart,  kidney, and liver health. Talk to your vet about the best medications and diets that can help improve your dog's immune system, heart, and overall health.

Support Your Dog's Heart Health

Given the impact that heart disease can have on your pet, taking preventative measures against heart disease is crucial. Of course, heart disease cannot always be prevented - especially the congenital types - but there are still things that can help your dog live a longer and healthier life.

The best approach is to feed your dog a healthy and nutritious diet, exercise regularly, and be on the lookout for common heart disease symptoms.

Regular visits to your vet are also crucial, as early diagnosis of heart disease and any underlying issues can lead to a better prognosis. It is also important to stick to the treatment plan your vet recommends; this will increase the chances of recovery and healthier life. After your vet prescribes medication or a veterinary diet, visit to order your pet’s prescriptions and have them conveniently shipped to your door.


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