Why Do Dogs Get Heart Murmurs

When the blood flowing through the heart is turbulent, a heart murmur develops. Some murmurs, particularly those heard in small puppies, may be “innocent” or “physiologic,” meaning they have no harmful repercussions on the health of your dog. Innocent heart murmurs in young puppies usually outgrow them after 5 months.

A heart murmur in an older dog can often be classified as either pathologic (caused by heart disease) or extracardiac, which is unfortunate because it is less likely to be considered “innocent” in older dogs (not caused by heart disease).

What are heart murmur grades in dogs?

Heart murmurs have various tones. Your dog’s heart will be listened to by your veterinarian, who will grade the murmur according to the following scale based on its intensity, timing, and location:

Grade 1: The least significant sort of cardiac murmur, hardly audible Soft murmur in grade 2, yet detectable with a stethoscope Grade 3: Intermediate loudness, canines with the most severe issues would at the very least have a grade 3 heart murmur. Grade 4: There is a loud murmur on each side of the chest. Grade 5: A roaring rumble Grade 6: The loudest sort of heart murmur, which may be felt by resting a palm on the dog’s chest wall.

What are the symptoms of heart murmurs in dogs?

The underlying cardiac issue that your dog has will have a big impact on the symptoms of a heart murmur. The following are some typical signs of heart conditions and diseases:

  • abnormal heartbeat or rapid heartbeat
  • chronic hacking cough
  • even while resting, excessive panting
  • fatigue or a lack of appetite
  • Fainting or collapsing
  • Blue-colored tongue and/or gums
  • significant water retention

What conditions cause heart murmurs in dogs?

There are numerous ailments and disorders that might result in a dog’s cardiac murmur.

Small dogs’ heart murmurs are typically brought on by a leaky mitral valve (the heart valve in between the left atrium and left ventricle). Blood can go from the left atrium to the left ventricle with the help of the mitral valve, but it cannot return to the left atrium. The valve can sometimes degenerate as a dog aged, allowing blood to seep backward. Endocardiosis, degenerative mitral valve disease, and chronic valve disease are all terms used to describe this disorder.

Heart murmurs in larger breed dogs are frequently brought on by a condition known as dilated cardiomyopathy (with a subsequent leaky mitral valve). The condition known as dilated cardiomyopathy weakens the heart’s pumping chamber muscles, which reduces the force of the heart’s contractions.

While these are the most frequent causes of heart murmurs, there are other other problems that might result in a murmur. Your pet’s heart may be appropriately evaluated by your veterinarian, who can also discover what is causing the heart murmur.

How can heart murmurs be treated?

The underlying reason of your dog’s cardiac murmur will determine the best course of treatment. Although a heart murmur that is innocent won’t need any treatment, your veterinarian will still want you to come in for follow-up visits to make sure the murmur goes away.

Medication, a particular diet, or surgery could be needed to treat a heart murmur brought on by a cardiac condition or defect. Your dog will at the absolute least need to see the vet every six months to monitor the murmur. Depending on your dog’s condition, a second echogram and/or X-rays may be needed during this visit.

Your veterinarian will provide you guidance on the best way to manage and treat the heart murmur in your dog.

What is the prognosis of a heart murmur?

The prognosis for a cardiac murmur can be favorable or bad depending on what caused it in the first place. The prognosis for benign murmurs that don’t need to be treated is often excellent to good. Heart murmurs brought on by extracardiac disease or a treatable functional issue may go away over time.

Long-term treatment for dogs with a leaky mitral valve can help them live longer or have better quality of life. The prognosis for a dog with dilated cardiomyopathy varies; regrettably, the prognosis is poor if the dog is already exhibiting symptoms of heart failure.

The prognosis for dogs with congenital cardiac problems varies; however, if the defect can be treated surgically, the prognosis is typically excellent.

Please take note that the information in this page is for informational purposes only and does not constitute medical advice for animals. Please schedule an appointment with your veterinarian for a precise diagnosis of your pet’s illness.

How long will a dog with a heart murmur survive?

Not to worry! Dogs with heart murmurs are extremely common, and many of them have normal lifespans. When your veterinarian listens to the heart during the physical examination, murmurs are identified. Breeds including Cavalier King Charles Spaniels, German Shepherds, Doberman Pinschers, Poodles, Cocker Spaniels, and Yorkshire Terriers are more prone to developing a murmur. A murmur might be “innocent” or “physiologic,” which means that the heart has not undergone any structural change, or it can be caused by a structural abnormality of the heart. Other systemic conditions like anemia, which might be the origin of innocent murmurs, can be treated and the murmur will go away. The murmur that puppies sometimes have at birth may disappear as they get older. But in dogs, heart valve and vessel deterioration is more frequently to blame. These alterations may develop with age or be present at birth. The mitral valve is most commonly affected by valvular degeneration in middle-aged to elderly tiny and toy breed dogs.

On a scale of 1 to 6, where 1 is very quiet and 6 is so loud you can feel it through your chest, murmurs are rated. Unfortunately, the grade of the murmur cannot be used to determine the severity of the condition. When a murmur is detected, your veterinarian may first advise getting x-rays to check for any indications of heart enlargement and to assess the lungs and blood vessels in the chest. While x-rays are useful for analyzing murmurs, an echocardiogram, or ultrasound of the heart and its arteries, is the best test to identify the origin of a murmur. The veterinarian can then determine which valve is leaking, the severity of the change, and how well the heart is adjusting to the change.

You will need to keep an eye on some things at home if your dog has been identified as having a heart murmur or another cardiac problem. Coughing is a symptom that heart disease may be becoming worse, as are fatigue after activity, an increase in respiratory rate, and an increase in breathing effort. Your veterinarian will collaborate with you to develop the appropriate treatment strategy and follow-up program for your dog based on the clinical indicators and diagnostic results.

Just because your dog has a heart murmur, heart illness, or any other type of cardiac issue does not necessarily mean that they are experiencing heart failure. Advanced heart disease causes advanced heart failure, which is when fluid builds up in the belly or the chest. Making sure your dog is on an effective heartworm preventive is essential since heartworm disease can also result in heart failure and heart disease.

Is a dog’s heart murmur a severe issue?

Heart murmurs can be dangerous, but they shouldn’t make you anxious. Heart murmurs can have a variety of causes, many of which are treatable, some of which may even go away on their own. The prognosis may be more guarded in more severe cases, particularly in older dogs, but keep in mind that detecting a heart murmur is the first step in treating the condition.

It can be challenging to comprehend heart murmurs. There are numerous potential causes, making it difficult to differentiate between the types and grades, especially if you don’t have a background in medicine. Consult your veterinarian if you have any additional questions regarding heart murmurs in dogs, and don’t be hesitant to ask her to direct you to client handouts and other materials that will provide you more details about your dog’s health. She might suggest that you speak with a veterinary cardiologist, who is frequently on staff at most veterinary specialty clinics.

The non-profit AKC, which was established in 1884, is the acknowledged authority on dog breeds, health, and training. The AKC is committed to improving dog sports and actively promotes responsible dog ownership.

When should I be concerned if my dog has a cardiac murmur?

Your veterinarian most likely detected a “whooshing sound” while listening to your dog’s heart if a heart murmur was found in your dog. Although it isn’t usually a cause for alarm, it can be.

A leaky heart valve, cardiac defects, frail heart muscles, heart worm disease, tumors, infections, and other conditions can cause the whooshing sound. Not all murmurs are alarming, despite the fact that they are not regarded normal. The majority of canine heart murmurs are caused by leaky mitral valves, which can be watched for several years before treatment is necessary. However, in some breeds, these murmurs can swiftly cause the dog to experience heart failure.

It is usually advisable to have your dog’s health “worked up” by your veterinarian if he or she has been diagnosed with a murmur. This would entail cardiac ultrasound, chest X-rays, and blood work with heartworm testing. You should most definitely seek medical assistance if your dog has a cardiac murmur and you notice coughing, congestion, change in breath sounds or rapid breathing, exercise intolerance, weakness or “fainting,” gray or blue gums, stomach distention, or lethargy.

How can a dog with a heart murmur be helped?

A veterinarian will attempt to treat the underlying cause of the heart murmur as well as any accompanying symptoms. Medication, food modifications, and exercise limitations are all possible medical treatments. Murmurs and young puppies may frequently resolve on their own in these cases.

When my dog has a heart murmur, should I walk him?

Take brief walks very early in the day because dogs with heart murmurs typically cannot handle hot, muggy weather. To assist keep their minds active over the summer, you can employ extra mental workout activities like puzzle games.

To lessen heart strain, try to wait 30 minutes after meals before going for walks or engaging in other physical activity.

Does having a heart murmur make a dog live less?

The good news is that many dogs with heart murmurs lead happy, healthy lives as long as they receive the right care and, if necessary, lifestyle adjustments are made. A better prognosis for heart diseases depends heavily on early identification. If you notice a cardiac murmur in your pet, we advise you to consult your veterinarian. Also follow up if your dog exhibits symptoms of cardiac disease, such as weakness, inability to exercise, a persistent cough, or weariness.

Can dogs get a heart murmur from stress?

Numerous illnesses can induce a murmur since it is merely auditory evidence of turbulent blood flow someplace in the heart. Some worry me more than others.

Innocent murmurs

A cardiac murmur in early puppies may be physiological ( i.e. a result of normal processes in the heart). The murmur in this instance is brought on by the pup’s rapid growth or the fact that it is a huge breed. Given that it is typically unimportant, this kind of murmur is also referred to as an innocent murmur. After a few weeks, it normally fades away on its own.

If your veterinarian thinks your puppy might have a benign murmur, they will recheck for it at the subsequent visit. If it’s still there, it might not just be a harmless murmur after all. Your veterinarian will likely then suggest more testing at that stage.

Anxiety-related murmurs

Dogs who are anxious or stressed out occasionally develop cardiac murmurs. This is typically caused by the heart’s rapid pumping. They gradually disappear on their own, just like physiologic murmurs do. Ask your veterinarian’s staff for suggestions on how to calm your dog down if visits to the vet are stressful for them. Additionally, your veterinarian may recommend anxiety-relieving drugs like gabapentin for dogs to help your dog feel less anxious before a visit to the doctor.

Anemia or low protein

Even when there is no indication of heart disease, underlying disorders might nevertheless result in a heart murmur. The consistency of a dog’s blood changes when they have anemia (low levels of red blood cells) or low protein levels. This causes a useful murmur. The murmur typically goes away on its own once your veterinarian treats the underlying condition.

Heart disease

Murmurs appear when actual heart issues exist because the heart muscle or the valves have structural damage. Dogs’ heart conditions can be acquired, hereditary, or congenital (existing from birth).

Heart disease in puppies

It’s possible that puppies with cardiac murmurs that are not benign murmurs were born with disorders like:

  • In dogs, the aorta and pulmonary artery have an aberrant connection called a patent ductus arteriosus (PDA), which is supposed to shut at birth. It results in an ongoing murmur as blood flows continually from the aorta into the pulmonary artery.
  • Pulmonic stenosis causes the pulmonic valve to narrow, increasing the amount of pressure required by the heart to force blood through the opening. Think about what happens to the water coming out of a garden hose if you close part of the opening with your thumb to get an idea of how this causes turbulent blood flow.
  • The aortic valve’s base narrows due to subaortic stenosis, requiring the heart to beat faster and apply greater pressure to force blood through the opening. Here too, the garden hose comparison holds true.

Heart disease in adult or senior dogs

Canines who are older or adults may acquire heart conditions that result in a heart murmur, such as:

  • Mitral valve dysfunction In older small breed dogs, the borders of the mitral valve (and occasionally the tricuspid valve) may wrinkle and deform. Because blood can now flow backward from the ventricle to the atrium instead of securely sealing the valve, a murmur is produced.
  • enlarged heart disease (DCM)
  • The heart’s walls, particularly those of the ventricles, may deteriorate and become frail, making it difficult for the heart to pump blood efficiently. In some breeds, this condition may run in the family. The FDA is also looking at the possibility of a connection between DCM and feeding grain-free, exotic ingredient, or boutique diets.
  • Canine heartworm disease
  • Adult heartworms reside in the right side of the heart and pulmonary artery, where they obstruct blood flow and occupy space. Heart murmurs can sometimes result from this.

It’s crucial to remember that the severity of a condition isn’t always correlated with the grade of a heart murmur. As their condition worsens, dogs with mitral valve disease do tend to have louder murmurs. On a physical examination, the veterinarian might detect a moderate murmur, though, for months or even years before it becomes an issue.

Dogs with DCM, on the other hand, might simply have a weak murmur or no murmur at all. However, their heart could be seriously deteriorating. Unfortunately, sudden death or acute collapse are occasionally the earliest indications of DCM.

Congestive heart failure

Congestive heart failure can develop from several cardiac conditions over time (CHF). This happens when the heart is unable to effectively pump enough blood to meet the needs of the body. Additionally, the heart’s pumping power is insufficient to stop blood from pooling inside the heart and its blood veins. Blood pressure issues and/or fluid accumulation in the chest or belly can both result from CHF.