Hearing that your dog has a heart murmur can be unsettling, especially when they seem perfectly normal at home. Many pet owners immediately worry about heart failure, but a heart murmur is not a diagnosis by itself. It is a finding that tells your veterinarian that blood flow through the heart is not completely silent or smooth.
Understanding what a heart murmur means, why it occurs, and what steps come next can help you feel more confident and prepared.
What Is A Heart Murmur?
A heart murmur is an abnormal sound your veterinarian hears while listening to your dog’s heart with a stethoscope. Instead of a quiet, steady rhythm, there is a whooshing or swishing sound caused by turbulent blood flow.
Murmurs are graded from Grade 1 to Grade 6 based on how loud they are. The grade helps describe intensity, but it does not always indicate how serious the underlying condition is.
Common Causes Of Heart Murmurs In Dogs
Heart murmurs can develop for several reasons, and not all of them are due to heart disease.
Innocent Or Physiologic Murmurs
Some puppies and young dogs develop soft murmurs that are not associated with heart problems. These often resolve as the dog matures. Temporary murmurs can also occur due to excitement, stress, fever, or pregnancy.
Structural Heart Disease
In adult and senior dogs, murmurs are often linked to structural changes in the heart. Mitral valve disease is one of the most common causes, particularly in small and medium-sized breeds. Congenital heart defects may also cause murmurs earlier in life.
Secondary Or Functional Causes
A murmur may also be caused by conditions outside the heart, such as anemia, dehydration, infection, or systemic illness. In these cases, addressing the underlying problem can reduce or eliminate the murmur.
Why Some Dogs Show No Symptoms
Dogs are very good at compensating for early heart changes. This is why many murmurs are discovered during routine wellness exams rather than after symptoms appear.
A dog can have a heart murmur and still eat well, play, and behave normally. While this is reassuring, it does not mean the murmur should be ignored. Monitoring helps determine whether it remains stable or progresses over time.
When A Heart Murmur Becomes More Concerning
Your veterinarian considers more than just the murmur itself. Signs that may indicate progression include:
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Coughing, especially at night or after activity
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Reduced stamina or tiring easily
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Rapid or labored breathing
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Fainting or collapse
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Weight loss or decreased appetite
If these symptoms are present, further evaluation is important.
What Tests Are Usually Recommended
At Norgate Animal Hospital, the next steps depend on your dog’s age, breed, murmur grade, and overall health.
Diagnostic testing may include:
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Chest X-rays to assess heart size and lung health
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Bloodwork to rule out secondary causes like anemia
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Blood pressure measurement
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Referral for an echocardiogram, an ultrasound that evaluates heart structure and function
An echocardiogram provides the most detailed information and helps guide treatment decisions.
Does Every Heart Murmur Require Treatment?
Not every murmur requires medication. Some dogs only need regular monitoring, especially if the murmur is mild and there are no symptoms.
If heart disease is diagnosed, treatment may include medications to reduce strain on the heart, control fluid buildup, or improve circulation. Starting treatment at the right time can significantly improve comfort and slow disease progression.
Why Ongoing Monitoring Matters
Regular rechecks allow your veterinarian to track changes over time and adjust care as needed. Monitoring helps catch progression early and prevents sudden complications.
Early intervention often means better long-term outcomes and a higher quality of life.
What You Can Do At Home
Pay attention to changes in breathing, coughing, energy level, and appetite. Keep routine veterinary visits consistent and follow any recommended monitoring plans.
If you ever notice sudden changes or worsening symptoms, contact your veterinarian promptly.
A Heart Murmur Is A Starting Point, Not A Verdict
Many dogs with heart murmurs live long, comfortable lives with proper monitoring and care. A murmur is simply the beginning of a conversation about your dog’s heart health.
If your dog has been diagnosed with a heart murmur or you have concerns about cardiac health, the team at Norgate Animal Hospital is here to help. Call (604) 980-2222 to discuss next steps or schedule an evaluation.