A heart murmur is characterized by abnormal heart sounds. They are common in dogs and are detected in routine checkups when a veterinarian listens to the heartbeat using a stethoscope.
Heart murmurs in dogs can be mild and difficult to detect or strong and loud enough for the veterinarian to feel when they place their hands on your pup's chest.
Various factors like defective valves, congenital heart disorders, and anemia can cause heart murmurs. Depending on the severity and underlying cause, heart murmurs in dogs can be a cause for concern or something not to worry about.
In this article, we will learn about the different types of heart murmur, the causes of heart murmur, and what we can do to treat the condition. Read on for more insight.
What are The Symptoms of Heart Murmurs in Dogs?
There aren't any symptoms associated with a heart murmur apart from an unusual sound in the heartbeat, but when the vet detects it, there is usually an underlying condition that has caused it. A heart murmur typically points to heart failure and is accompanied by other signs like;
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Exercise intolerance
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Coughing
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Heavy breathing while resting
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Weight loss
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Pale or blue gums
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Poor growth
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Poor oral/dental health
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Decreased stamina
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Weakness, collapsing, or fainting
What Causes a Canine Heart Murmur?
Turbulent blood flow results in a whooshing sound when the heart valves are not working properly. Some of the abnormal conditions include;
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Obstruction of the valve
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Abnormal valve shape or size
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Blood flows back through a leaky valve because it does not shut tightly
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Abnormal opening between structures
Heart murmurs in dogs are caused by disorders or heart disease that cause disturbance of the normal flow of blood in the heart and through the valves.
Congenital Heart Disorders
Congenital heart disorders are conditions that develop before birth and can cause improper growth of blood vessels or the heart. The heart can be underdeveloped and the valves can develop with defects that lead to an obstructed flow of blood.
Types of Heart Disease in Dogs
Heart murmurs are generally categorized into the following categories:
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Congenital heart murmurs: Dogs are born with congenital heart murmurs which are caused by structural heart abnormality. These heart murmurs are soft and quiet and in puppies they are benign. Puppy heart murmurs go away as they grow, often by 6 months.
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Acquired murmurs: A heart murmur that develops later in life can be caused by cardiac muscle disease or heart valve abnormalities. An adult dog that develops this condition can recover for as long as they get proper treatment so that the condition does not develop into congestive heart failure.
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Systolic murmurs: These heart murmurs occur when the heart contracts to pump blood.
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Diastolic murmurs. These heart murmurs are uncommon in dogs and they happen when the heart muscles relax between beats producing a whooshing sound.
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Continuous murmurs: These are heart murmurs that occur throughout the cardiac cycle.
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Innocent murmurs: An innocent heart murmur is a mild murmur that is barely audible. Young puppies that have innocent heart murmurs outgrow them by the time they are 5 months.
Heart murmur grades in dogs
A heart murmur is classified according to grades, from I to IV. These grades map out the severity or intensity of the murmur. Higher grades on the scale mean the underlying heart disease has progressed and the murmur becomes louder and easier to perceive on a stethoscope.
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Grade I Murmur: This is the initial phase of heart murmurs in dogs. It is also the less serious phase of a heart murmur, barely audible by a stethoscope, and requires a very quiet room for veterinarians to puck up the whooshing.
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Grade II Murmur: This is the second phase of the murmurs in dogs. They are soft murmurs and can be easily heard with a stethoscope.
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Grade III Murmur: These are loud murmurs in a dog's heart. This stage signifies a problematic phase that must be properly addressed medically.
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Grade IV Murmur: These are loud murmurs that the vet can easily hear with a stethoscope on both sides of the chest.
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Grade V Murmur: These are very loud murmurs. The vet can feel the murmur by simply placing their hand on the dog's chest.
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Grade VI Murmur: This is the most severe phase of the heart murmur in dogs. It is also the loudest heart murmur.
When the vet detects any scale of a heart murmur, they follow up with further tests to determine the underlying cause. The prognosis and treatment plan depends on the underlying cause of the heart murmur and its impact on the dog's health.
Veterinarian Treatment of Canine Heart Disorders
The treatment plan focuses on addressing the underlying disease or defects. The vet can recommend a combination of medication, special diet, supportive care, and routine check-ups every 6 months to monitor the condition.
Remember that innocent murmur in puppies is not severe or a cause for concern, they fade away usually within 6 months after birth. The vet will simply recommend monitoring every 3 to 4 weeks to make sure no other issue develops before the 6 months elapse.
The Bottom line
Murmurs are common in dogs. They are not a cause for alarm but should not be ignored because some murmurs are caused by heart diseases that must be treated by a professional.
As a pet parent, you should always monitor your pup for any signs of heart disease like exercise intolerance, heavy breathing, coughing, and poor growth.
