Heart Murmurs in Dogs

heart murmur in dogs

Heart murmurs are found when a veterinarian listens to a dog’s heart and hears a whooshing sound. It’s not constantly a reason for concern, however it can be. In dogs, common causes consist of heart valve issues, heartworm disease, heart problems, growths, or weakening of the heart muscle. If your dog has problem breathing, sounds busy or coughs, has a pot tummy, passes out, or suddenly collapses, he could have a heart condition. Treatments can include surgery or addressing any underlying problems that might be causing the murmur.

What Is It?

A heart murmur is an abnormal sound that a veterinarian hears when listening to a dog’s heart through a stethoscope. Normally, a veterinarian hears 2 noises, a “lub” and a “dub,” which are the sounds of the heart valves closing as blood circulates through the heart. An additional “whooshing” sound or other noise, called a heart murmur, is generally associated with a disturbance of the generally smooth flow of blood through the heart.

Vets rank the intensity or volume of a heart murmur in grades from one to 6, with one being hardly audible and six being the loudest. There is also a one-to-five ranking system that works the exact same method. These grades do not necessarily associate with the seriousness of the heart condition; they are merely one of several ways that veterinarians attempt to characterize the murmur.

Though it’s not considered normal, a heart murmur is not constantly a cause for concern. It may, nevertheless, be an indication of a heart problem. Depending upon your dog’s condition, the veterinarian might wish to carry out additional diagnostic tests to figure out the cause of the murmur.

Symptoms of Heart Murmurs in Dogs

Heart murmurs are brought on by any number of conditions that can produce turbulence in the circulation of blood through the heart. In dogs, typical causes for heart murmurs consist of:

  • Heart valve shortages or obstructions
  • Flaws in the heart walls
  • Dilated cardiomyopathy (weakening of the heart muscle walls).
  • Heartworm disease.
  • Endocarditis (an infection of the heart valves).
  • Tumors.

Sometimes, a vet finds a heart murmur in a young pup. Though this might suggest the existence of a hereditary heart condition (a defect the puppy was born with), in most cases it is what is called an innocent murmur, indicating that it is not associated with a heart problem. These murmurs usually vanish by the time the animal has to do with 4 months of age. If a murmur does not solve, your veterinarian might recommend diagnostic screening to investigate it further.

Not all dogs with a heart condition show outward signs. However, if you have been told that your dog has a heart murmur, you should expect signs such as:

  • Coughing.
  • Hard or rapid breathing.
  • Congestion or “loud” breathing.
  • Exercise intolerance (hesitation to workout).
  • Weakness or lethargy (exhaustion).
  • Passing out episodes.
  • Gray or blue gums.
  • Stomach distention (a pot-bellied appearance).
  • Collapse.

If your dog displays any of these signs, call your veterinarian for recommendations or to set up an examination.

Small Puppies

Soft heart murmurs (grade 1/6 to 2-3/6) can take place in young animals and are of no effect to them. These kinds of murmurs are called “innocent” murmurs. They are soft and generally go away by 14 weeks of age.

A cardiologist should evaluate Loud heart murmurs (Grade 3-4/6 to 6/6) in a new young puppy or cat. This may indicate that genetic (present at birth) heart problem is present. The cardiologist will perform an echocardiogram along with other tests (EKG, blood pressure, etc.) to assess the heart and figure out if congenital heart disease is present. Depending on the disease present, some hereditary diseases can be fixed or made better with an interventional catheter procedure.

Older, Small Breed Dog

Heart murmurs in these dogs might suggest that these dogs have leaking mitral valve (the heart valve in between the left atrium and left ventricle). The mitral valve’s task is to enable blood to flow from the left atrium to the left ventricle but not permit blood to flow backward from the left ventricle to the left atrium. This valve degenerates as a dog’s age, and when it does, the older valve permits blood to leakage in reverse. We describe this disease as chronic valve disease, endocardiosis or degenerative mitral valve disease.

Mild chronic valve disease that leads to small leakages across the mitral valve generally does not create an issue for a dog. The disease is gradually progressive most of the times, and the leak will continue to intensify over months to years. If the disease ends up being severe, the dog is at danger for establishing congestive heart failure. Heart disease indicates that the leak across the heart valve overwhelms the heart and fluid goes from the heart backward into the lungs (instead of from the heart forward to the body). Signs of congestive heart failure consist of cough (particularly a cough at rest), a fast breathing rate, problem breathing, fainting, weakness, sleepiness, workout intolerance, and stomach distension.

A cardiologist can perform an echocardiogram and determine the stage of chronic valve disease present. The presence or lack of heart disease is then detected by X-ray of the chest. If heart disease exists, oral medications can be recommended and some dogs can do well with these medications for 1-2 years.

Middle-aged to Older Big Breed Dog

…especially a Doberman Pinscher, Irish Wolfhound, Great Dane, Boxers, St. Bernards, Newfoundlands, Cocker Spaniels, Dalmatians or Portuguese Water Dogs.

Heart murmurs in these dogs might indicate that they have a disease called dilated cardiomyopathy (with a subsequent leaky mitral valve). Dilated cardiomyopathy is a disease of the pumping chamber (ventricle) of the heart where the muscle becomes weakened and the contraction of the heart is reduced. When the ventricle is not able to pump blood to the body, fluid goes from the heart backward into the lungs (instead of from the heart forward to the body). This is called congestive heart failure. Signs of congestive heart failure include cough (particularly a cough at rest), a quick breathing rate, problem breathing, fainting, weak point, lethargy, exercise intolerance and stomach distension. Also, since the heart is not pumping efficiently, these dogs can establish extensive weak point, lethargy, workout intolerance and fainting. Regrettably, they can likewise die unexpectedly from unusual heartbeats from the diseased heart chambers.

A cardiologist can perform an echocardiogram and identify if dilated cardiomyopathy is present in susceptible breeds. Oral medications can be started in the preclinical (asymptomatic) phase of dilated cardiomyopathy and sometimes, these medications can delay the progression of the disease to the development of heart disease. If a dog establishes scientific symptoms of heart disease, X-rays are used to confirm the presence and identify the seriousness of the heart disease. If heart disease exists, oral medications can be prescribed and some dogs can do well with these medications for 1-2 years.

Diagnosis for Heart Murmurs in Dogs

To figure out the cause of a heart murmur, your vet may advise a variety of tests, such as:

  • Blood tests, consisting of heartworm tests.
  • Chest radiographs (X-rays) to examine the heart, blood vessels, and lungs.
  • An electrocardiogram (ECG).
  • An echocardiogram (an ultrasound exam to assess heart structure and function).
  • Blood pressure tests.

Treatment for Heart Murmurs in Dogs

Treatment depends on the cause of the heart murmur and your dog’s condition. If your dog is disappointing any signs of heart problem other than the murmur, your vet may choose to monitor your dog and provide treatment only if signs happen.

In many cases, such as when a heart murmur is caused by heartworm disease, treatment may solve the heart murmur totally. If the murmur is brought on by a congenital condition, surgery may be advised. In other cases, the heart murmur might remain, however medications can assist make your dog more comfortable and enhance your pet’s longevity.

Not all heart murmurs need treatment. Just keeping the dog slim and active, is all that’s needed for grades 1&2.

With louder murmurs, there are medications which can support how the heart pumps and lengthen a good quality of life. These drugs include angiotensin-converting enzyme inhibitors, diuretics, and positive inotropes.

An especially important medication is pimobendan (TM Vetmedin.) This heart medication is unusual because it’s been clinically proven to extend life when it’s started even prior to the dog ends up being sick. However, it’s best started at a particular stage, where the heart is enlarged however the dog isn’t showing signs of heart disease.

To hit this sweet spot involves dogs with peaceful murmurs being scanned every 6-12 months. This enables the cardiologist to detect the heart enhancement early to start the dog on pimobendan.

Prognosis or Dog Heart Murmur Life Expectancy

When a heart murmur is determined in your healthy dog, do not panic. There’s every possibility the dog may never establish full-blown heart problem.

Your veterinarian will tape-record the grade of the heart murmur in dogs in addition to the heart murmur in felines, in addition to their heart rate. They will utilize this to monitor your canine companion and spot signs of deterioration. Must this happen, then further tests might be essential.

Gladly, modern medications can support a dog with cardiovascular disease and enable them to continue with the exceptional lifestyle for months or years to come.

Remember, each dog is a person. Some defy the chances and outlast their predicted life expectancy, whilst others can unfortunately suffer a disastrous event, such as a heart attack, and deteriorate all of a sudden. However by being proactive and working with your vet, there’s every chance that you can make a difference and keep your pet pleased for longer.

Reyus Mammadli
Having engineering and medical education, in recent years actively engaged in the study of the development, reproduction of domestic animals. Special attention is paid to the treatment and prevention of diseases of Pets.
Pet Health
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