A Dog Heart Murmur

First, let's define exactly what a heart mumur is -

Heart murmurs are basically an abnormal heartbeat - an irregularity or unusual rythm, and different causes can result in slight variations in the 'murmur' itself.

A canine heart murmur can be present in newborn puppies or develop in later life as a result of disease, illness or age.

There are several different things that can cause a canine heart murmur, and it's important to get all your facts right...... that way you will be in a better position to help your dog get better.

When it comes to diagnosis, dog heart murmurs are divided into different grades depending on their severity (including how loud they are). Grade I being those of least concern, and Grade VI being the most dangerous.

Grades I and II - there are often no other symptoms and a dog heart murmur of this kind is likely to be watched rather than treated, at least at first.

Grades III and IV - a puppy or dog may seem to tire easily, lose his appetite, or have a persistent cough. At this level medication is often recommended and surgical options may be considered.

Grade V and VI - at this point things get a lot more serious and your dog may seem very unwell. Medication and surgery will most likely be needed, and canine congestive heart failure can result.

My Puppy Has A Canine Heart Murmur!

Some breeds seem to have a higher incidence of cardiac birth defects which result in dog heart murmurs.

For example, Patent Ductus Arteriosus (PDA) is more often seen in Poodles, Chihuahua, Maltese, Shetland Sheepdogs and other herding breeds such as the German Shepherd and various Collies.

Subvalvular Aortic Stenosis (SAS), a defect of the aortic valve, occurs more frequently in Boxers, Rottweilers, Golden Retrievers, Bernese Mountain Dogs, German Shorthaired Pointers and several other large breeds.

Bulldogs, Schnauzers, many terrier breeds, Beagles and Samoyeds may be predisposed to suffering from Pulmonic Stenosis (defect of the pulmonary valve).

Both PDA and SAS tend to produce a dog heart murmur as a symptom.

Your veterinarian may notice an irregularity in your pups' heartbeat during a routine check up, or symptoms such as lethargy, coughing, weakness or white/blue gums or tongue may prompt a vet visit that uncovers cardiac problems.

Minor dog heart murmurs in puppies tend to earn a 'wait and see' type of approach if the pup seems otherwise happy and healthy. This is because many pups outgrow them given time. Short episodes of heart murmurs in puppies may also appear during particular growth spurts or developmental changes. These are usually short-lived.

Symptoms of a dog heart murmur in puppies

• Poor weight gain, slow growth
• Excessive sleepiness, lack of 'puppy playfulness'
• Coughing, especially at night or first thing in the morning
• Pale gums/tongue

A Canine Heart Murmur In Older Dogs

A dog heart murmur which develops later in life is usually a result of disease or old age.

It can sometimes be caused by something simple like anemia - and the most common reason for a dog to be anemic is that he/she has a parasitic infection. Canine worms such as whipworms or hookworms can make a dog anemic.

When it comes to the more serious reasons for a dog heart murmur, heart valve disease is the most common culprit. The Mitral valve is often affected and tends to deteriorate with age. Again some breeds are more prone than others to mitral valve disease and these include many toy and miniature breeds, especially Cavalier King Charles Spaniels.

This condition is usually considered degenerative (ie it's a condition related to aging), but occasionally it can be caused by an infection that affects the heart even though it may have started elsewhere in the body.

In addition to a canine heart murmur, the most common symptoms of this type of heart disease are lethargy and a low-tolerance for exercise (your dog may breathe very rapidly, pant excessively or have difficulty standing after exercise) and have a persistent cough. The cough happens because the effects of the damaged valve puts pressure on the lungs which slowly fill with fluid.

Diagnosing A Dog Heart Murmur

There are several ways that your vet can use to make a diagnosis of a heart murmur in your dog.

Physical Exam

The first is to listen to his/her heartbeat through a stethoscope - and this is how most heart murmurs, particularly in puppies, is first noticed.

If you're not familiar with the sound of a normal canine heartbeat it's almost impossible to detect the murmur yourself, but the general description of a heart murmur is that it 'softens' the precise and regular sound of a normal heart.

The extra turbulence that occurs as the blood flows through the heart may cause a whooshing or hissing sound along with the normal 'lub-dub' heartbeat. Some murmurs have even been described as sounding like a washing machine (often indicates PDA).

If your vet notices that your pup/dog has pale or blue-tinged gums, this may also make him consider heart problems.

Chest X-Rays

If your vet is concerned about a canine heart murmur, he will likely take some chest x-rays as the next step in making a diagnosis.

Heart disease often alters the physical shape of the heart (causing certain areas to become enlarged) which is visible on an x-ray.

Also any fluid that has collected in the lungs (as in Mitral Valve Disease) will also be visible.

EKG - Electrocardiogram

This test will show your dogs heartrate and rythm and can help detect blockages or other abnormalities that can be the cause of a dog heart murmur.

Echocardiogram

This is basically an ultra-sound procedure and can give veterinarians a very clear picture of what is going on inside your dogs' heart.

It shows the way each part of the heart contracts, the condition of individual heart valves and major blood vessels and how thick the walls of the heart are. It is a good way for your vet to get an idea of how well your dogs' heart is performing overall.

Other tests that your vet may use include a blood pressure test and an evaluation of kidney function.

Treating A Dog Heart Murmur

There are a range of medications that your vet can prescribe, including ACE Inhibitors, Vasodilators, Diuretics, Beta Blockers, Digoxin and various anti-arrythmia drugs.

These all work basically the same way as they do in human heart patients, and are similar in terms of effectiveness. Any of them can have side effects and your vet will monitor your dog closely if he takes them. In many cases they can

If the medications don't work, or the dog heart murmur is severe enough to require surgery, there are a couple of options. It would seem that canine cardiac surgical procedures are more likely to be successful in puppies who have congenital heart problems than those that occur in older, or sick, dogs.

There are two surgical options for repairing Patent Ductus Arteriosus in puppies, and the success rate is good. Performing the surgery as early as possible gives the pup the best chance of making a full recovery.

Subvalvular Aortic Stenosis is more difficult to repair surgically, although Balloon Valvuloplasty has been shown to help somewhat in up to 85% of cases, however it has a fairly significant risk attached and between 5 and 10% of dogs may not survive the surgery. Medications and lifestyle modifications are the best way to control this condition.

A Pericardiectomy can be performed to drain fluid around the heart that may be putting pressure on it. This often occurs when a dog has a heart tumor, and although a dog heart murmur is rarely a sign of cancer, unusual heart sounds, a rapid but weak heartbeat and an enlarged chest can by symptoms.

Keeping Your Dogs' Heart Healthy & Strong!

You can't do anything abour preventing a congenital dog heart murmur if your pup already has one (but when buying a puppy, especially if it's from a breed known to have genetic cardiac conditions, choose a breeder who tests for them and never breed a dog who has a heart problem) - but you can take steps to make sure his heart gets the best possible chance of staying healthy and strong.

ANY puppy or dog can benefit from certain natural products which support a healthy heart and can even reduce or prevent certain degenerative conditions.

If you have a puppy or dog with a minor dog heart murmur, or one who is totally healthy (and you want him to stay that way!) there are natural herbal/natural products that you can use as a preventative measure.

They can help strengthen your dogs cardiac and circulatory systems, and improve his immune function. Here are a couple that are worth checking out Resvantage Canine for Dog and Canine Hearty Heart for Dog Heart Disease

There are also natural supplements which include certain vitamins and minerals which can help many dogs with heart issues. They DO NOT replace mainstream medications or surgery, but should be used alongside them.

Do remember to tell your vet about any product or supplement you give your dog though, just because something is 'natural' it doesn't mean that it can't (or won't) interact with another medication or be inappropriate for your individual dogs' condition.

Some natural supplements that are often recommended include Omega-3 Fish Oils, the amino acids Taurine and L-Carnitineand certain , and Vitamin/Mineral Supplements

Try these online stores for a wide selection of natural products and supplements that can help with a huge range of canine health problems (not just heart disease!)....

Canine Congestive Heart Failure

Canine Health Issues

Parvo In Puppies

Dog Diseases And Symptoms

Health Insurance For Your Dog

Ask A Vet A Question

Return to Home Page from Dog Heart Murmur