Understanding Heart Murmur in Dogs: Symptoms and Treatment

If you’ve ever sat beside your pup, feeling their chest rise and fall, and wondered, “Is everything okay in there?” you’re not alone. One of the more confusing and concerning health issues dog parents encounter is a heart murmur in dogs. Learning about heart murmur in dogs symptoms and treatment can make the experience far less frightening and help you take better care of your furry friend. Not every murmur is serious, but every murmur deserves understanding and attention.

What is a Heart Murmur?

A heart murmur is an unusual sound created by turbulent blood flow in or near the heart. When your vet listens with a stethoscope, they expect a steady rhythm as the heart’s valves open and close. A murmur is an extra sound, often described as a whoosh or a swirl of air.

The presence of a murmur doesn’t always mean serious disease. Some murmurs are innocent or physiologic, especially in puppies and young dogs. These often fade as the dog grows. Others are pathologic, which means they’re caused by structural problems or disease within the heart. Knowing the heart murmur in dogs symptoms and treatment helps you understand which type your pet may have.

Why do Heart Murmurs Happen?

There are several reasons dogs develop heart murmurs, and not all are cause for concern.

• Innocent or physiologic murmurs
  Young puppies, especially those growing quickly, can have mild murmurs that usually disappear by four to six months of age.
• Anxiety, excitement, or stress
  A dog’s heart beats faster during stressful moments, such as a vet visit. That temporary increase in blood flow can cause a murmur that isn’t linked to disease.
• Extracardiac or functional causes
  Conditions such as anemia, fever, or infection can change how thick or thin blood is. When the underlying issue resolves, the murmur often disappears.
• Structural heart disease
  Some dogs are born with congenital defects, such as holes between heart chambers or valve abnormalities. Others develop changes later in life, such as leaky or thickened valves or weakened heart muscle.

A loud murmur doesn’t always mean worse disease, and a faint one doesn’t always mean mild disease. The only way to know for sure is with proper diagnosis and understanding of treatment options.

Symptoms of Heart Murmur in Dogs

Many murmurs are discovered during routine checkups, before symptoms ever appear. Still, some dogs may show signs of heart trouble. Keep an eye out for:

• Coughing, especially at night or after exercise
• Weakness, tiredness, or reluctance to play
• Loss of appetite or weight loss
• Rapid or labored breathing
• Pale or bluish gums
• Fainting or collapsing
• A vibration you can feel on your dog’s chest if the murmur is strong

These are among the most common heart murmur in dogs that suggest the heart may not be pumping efficiently. If you notice any of them, schedule a vet visit right away.

How do Vets Diagnose Heart Murmurs?

Once your vet hears a murmur, they may recommend tests to determine whether there’s underlying disease and how advanced it is. These may include:

1. Physical exam and history to note symptoms and how the murmur sounds in different positions
2. Bloodwork to rule out anemia or infection
3. Chest X-rays to check heart size and lung condition
4. Electrocardiogram (ECG) to measure heart rhythm and detect irregular beats
5. Echocardiogram (ultrasound) to visualize how blood flows through the heart and how well the valves and chambers work
6. ProBNP or NT-proBNP blood tests to see how much strain the heart is under
7. Holter monitoring for long-term rhythm tracking if needed

These tests help your vet determine whether the murmur is harmless or a sign of disease requiring treatment.

Understanding Murmur Grades

Vets classify murmurs from Grade I to Grade VI, based on how loud they sound and whether they create vibrations you can feel.

• Grade I – very faint, barely audible
• Grade II – soft but easy to hear
• Grade III – moderately loud
• Grade IV – loud, often with vibration
• Grade V – very loud, strong vibration
• Grade VI – so loud it can be heard without the stethoscope touching the chest

The grade doesn’t always reflect how serious the condition is. A quiet murmur can still be linked to significant disease, while a loud one may not be dangerous.

Treatment for Heart Murmurs in Dogs

When it comes to heart murmur in dogs, the goal is to address the underlying cause rather than the murmur itself.

• Innocent murmurs only need monitoring. Your vet will recheck your dog periodically to make sure nothing changes.
• Treat underlying issues such as infection or anemia, and the murmur often disappears.
• Medication may be prescribed to ease the workload on the heart or manage fluid buildup.
• Dietary management can help in advanced disease, with controlled sodium and balanced nutrition.
• Supplements such as omega-3s, antioxidants, and CoQ10 may support heart health when recommended by your vet.
• Surgery or catheter procedures can correct certain congenital defects, improving or resolving the murmur entirely.
• Follow-up care is essential since many heart conditions change over time.

With proper treatment, many pets live long, happy lives filled with joy and fun.

What Can You Do at Home?

• Don’t skip wellness exams. Vets often find murmurs during routine checkups, long before symptoms appear.
• Keep your dog at a healthy weight. Extra pounds put added stress on the heart.
• Stay active but sensible. Gentle, regular exercise supports circulation and keeps your dog fit.
• Take care of their teeth. Oral bacteria can enter the bloodstream and cause heart infections.
• Know your breed’s risks. Some breeds are more prone to valve or heart muscle problems.
• Watch for red flags. If your dog starts coughing, tiring easily, or breathing rapidly while resting, contact your vet right away.

Outlook

Prognosis varies widely. Some dogs with mild murmurs never develop symptoms and live full lives. Others, especially those with valve disease or heart muscle weakness, may progress to congestive heart failure. The key is early detection and consistent care.

Remember, a murmur isn’t a death sentence. It’s information that helps you act before problems become serious.

Protecting Your Dog’s Heart and Your Peace of Mind

Caring for a dog with a heart murmur often involves tests, medications, and follow-up care. These expenses can add up quickly, which is why pet insurance can make such a difference. Having coverage allows you to focus on your dog’s health instead of worrying about unexpected bills.

If you haven’t already explored pet insurance, now is the perfect time. A good plan can help cover future exams, diagnostics, and treatments related to heart murmur in dogs. When it comes to your pup’s heart, a little preparation today can bring comfort, confidence, and more tail wags tomorrow. 

References:

https://vcahospitals.com/know-your-pet/heart-murmurs-in-dogs

https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information/get-jump-heart-murmurs

https://www.sciencedirect.com/science/article/pii/S1760273415000636

Disclaimer

The information contained on this blog is intended for informational and educational purposes only and should not be construed as medical advice. It is not a substitute for professional veterinary care. Always consult with your veterinarian before making any changes to your pet's health care or treatment plan.

The authors of this blog are not veterinarians and do not claim to be experts in pet health. The information provided here is based on our own experiences and research, as well as information from reputable sources. However, we cannot guarantee the accuracy or completeness of this information.

We encourage you to do your own research and consult with your veterinarian before making any decisions about your pet's health.