A Vet’s Guide to Understanding Dogs with Heart Murmurs

veterinarian listening to a golden retriever's heart

Heart disease is a frequent reason for dogs to visit the emergency room. When older small-breed dogs struggle to breathe, it’s essential to be concerned about congestive heart failure. In this condition, the heart pumps ineffectively, causing fluid to accumulate in the lungs and pulmonary edema. Urgent action is required to eliminate the fluid using diuretics and provide oxygen for easier breathing.

This article provides insights into the life expectancy of dogs with heart murmurs. We will focus on mitral valve disease, which is the most common cause of murmurs and heart failure in older dogs. Although it’s easy to feel hopeless, working closely with your family veterinarian and a veterinary cardiologist can offer interventions to help dogs with heart murmurs live long and happy lives.

How Does a Heart Murmur Affect a Dog’s Quality of Life?

veterinarian inspecting dog

Dogs with heart murmurs can lead normal lives, especially in the early stages of heart disease. During the initial phases of mitral valve disease, dogs may not show any apparent clinical signs. However, as the disease progresses, their cardiac function declines, leading to symptoms such as weakness, lethargy, coughing, exercise intolerance, poor appetite, weight loss, and even collapse. In advanced stages of the disease, dogs may experience abdominal distension and fluid retention in their bellies. These dogs should avoid stressful situations and be exercise restricted.

Understanding the Severity of Heart Murmurs in Older Dogs

Heart murmurs in dogs, especially those caused by mitral valve disease, should never be taken lightly. This condition is always progressive, causing degenerative changes to the heart valves. As the valves become more diseased, blood flow is impaired, leading to enlargement of the left side of the heart. Dogs with cardiac enlargement are at a higher risk of developing heart failure if left untreated. Therefore, if your veterinarian detects a heart murmur in your dog, it’s crucial to perform diagnostics to determine the stage of heart disease. Chest X-rays can reveal heart enlargement, and therapy with pimobendan is necessary if enlargement is present. Regular screenings every 6 months are advised in the absence of cardiac enlargement.

Impact on Life Expectancy Based on the Cause of Heart Murmurs

The life expectancy of dogs with heart murmurs depends on the underlying cause. Various diseases can lead to heart murmurs, including mitral valve disease, dilated cardiomyopathy, and congenital heart defects. Here’s a summary of the impact of these diseases on a dog’s life expectancy:

See also  Xoloitzcuintli: The Extraordinary Hairless Dog Breed
Type of heart murmurs Impact on life expectancy
Mitral valve disease Varies according to stage
Dilated cardiomyopathy Varies according to breed
Congenital heart defects Varies depending on defect

Life Expectancy and Survival Rate With and Without Treatment

Life expectancy for dogs with heart murmurs is closely linked to the disease causing the murmur. Let’s specifically look at mitral valve disease, the most common cause.

  • Dogs with stage B1 heart failure can live for months to years without treatment.
  • Once the disease progresses to stage B2, treatment is essential to delay its progression. Dogs treated with pimobendan, according to the EPIC study, lived an average of 1,228 days (3.3 years) compared to dogs that received a placebo, which had an average survival of 766 days (2.1 years).
  • Dogs reaching stage C disease will not survive without treatment. However, with proper care, they can live for up to a year before succumbing to the disease.
  • Stage D disease represents the end stage, and even with treatment, survival may be limited.

Can Dogs Survive a Heart Murmur Without Treatment?

Dogs can live for an extended period without treatment during the early stages of heart disease. Murmurs are often discovered incidentally during routine veterinary visits, and many dogs may not have any signs of cardiac enlargement. However, it is crucial to conduct diagnostics and consult a cardiologist to determine if early intervention is necessary.

For dogs with evidence of cardiac enlargement, treatment is recommended to delay the progression of congestive heart failure. Without treatment, the disease will inevitably progress, leading to pulmonary edema. In cases where owners choose not to pursue aggressive treatment, humane euthanasia is strongly advised.

Improving a Dog’s Life with Heart Murmurs

Dogs with heart murmurs can lead happy lives, especially in the early stages of the disease. They can maintain a normal lifestyle, but it’s important to limit their exercise as the disease advances. Stress-free living is essential. Consider a cardiac diet with reduced sodium intake and appropriate protein levels. Additionally, supplementing their diet with omega-3 fatty acids can offer cardiac protection. Adhering to medication schedules is vital, and close communication with a family veterinarian and a veterinary cardiologist will ensure the best care for dogs with heart disease. Regular echocardiograms should be scheduled based on the cardiologist’s recommendations, with medication adjustments as needed.

How Vets Treat Heart Murmurs

Fortunately, there are several treatments available for dogs with heart murmurs caused by mitral valve disease. In the early stages, no treatment may be required. Oral medications are typically not recommended until dogs reach stage B2 of the disease. However, exceptions exist, and a cardiologist will provide guidance. Stage B2 means there is both a murmur and evidence of heart enlargement on radiographs or an echocardiogram.

See also  Discover the Toughest Toys That Will Last!

Once dogs reach stage B2, the first-line treatment recommended is pimobendan. This medication improves heart contractility and protects the heart. Clinical signs of heart disease improve, and the lifespan of dogs with this condition is prolonged. Additional medications such as benazepril, furosemide, and spironolactone may be prescribed at this stage.

Dogs that progress to stage C disease develop congestive heart failure and often require hospitalization for diuretic therapy and oxygen administration. After stabilizing their condition, additional medications such as ACE inhibitors and diuretics are prescribed if necessary.

Stage D heart disease represents the end stage, where standard treatments for heart failure may no longer be effective. Dogs in this stage may require high doses of cardiac medications or changes in diuretic therapy. Palliative treatments like abdominocentesis may be performed to relieve fluid buildup and make dogs more comfortable.


Is a Heart Murmur a Death Sentence for a Dog?
A heart murmur is not a death sentence. However, it is often caused by mitral valve disease, which is progressive and irreversible. While some dogs may die from this disease, others may pass away due to other underlying conditions.

How Serious is a Heart Murmur in an Older Dog?
A heart murmur should always be taken seriously and thoroughly investigated. Early diagnosis can lead to interventions that may prolong a dog’s life. An echocardiogram is recommended for any dog with a diagnosed heart murmur.

How Quickly Does a Heart Murmur Progress in Dogs?
The progression of cardiac disease varies from dog to dog. While some dogs may progress slowly over 6 months to a year, others may experience a faster progression. Regular echocardiograms every 6 months are recommended, and later stages of heart disease may require closer monitoring.

Is Exercise Good for Dogs with Heart Murmurs?
Normal exercise is beneficial for dogs in the early stages of heart disease as it helps maintain a healthy body weight. However, dogs with advanced heart disease or heart failure should avoid strenuous exercise as it can strain the heart and worsen clinical signs.

Are Heart Murmurs Common in Older Dogs?
Heart murmurs are extremely common in older dogs, particularly small breeds. Approximately 10% of dogs presented to veterinarians have heart disease, and about 70% of those cases involve mitral valve disease.

Remember, understanding and managing heart murmurs in dogs require collaboration between you, your family veterinarian, and a veterinary cardiologist. By working closely with these professionals, you can ensure your furry friend receives the best care to live a long and fulfilling life.

To learn more about Katten TrimSalon, visit kattentrimsalon.com.