So, your veterinarian tells you during a wellness exam that your dog has a heart murmur. Your pal acts fine, eating and drinking, not coughing and full of energy, and you are worried.
It sounds so scary.
What is a heart murmur? Our dogs and we humans basically have the same heart.
Your dog’s heart pumps blood to its whole body by using four chambers. There are two on the top of the heart and two on the bottom.
For blood to flow in the proper direction, a one-way valve between each of these chambers opens and closes as blood fills a chamber, then empties out again.
This is what gives the heartbeat its characteristic “lub-dub” sound.
A heart murmur is an abnormal sound made when blood does not flow smoothly through the heart. The change causes a swishing sound heard by your veterinarian with the stethoscope.
Although there are various reasons for a murmur, in dogs it is commonly the result of leaky valves, ie. valves that do not open and close correctly.
Age-related degenerative heart disease is the most common degenerative heart disease in dogs, making up 75% of canine heart disease.
According to Dr. Claire Wiley, VMD, DACVIM, executive director of the AKC DNA Program, the earliest sign of valve leakage is normally a heart murmur caused by the blood flowing backward through a valve, causing a murmur heard by your veterinarian.
Your veterinarian will often ask for an X-ray of your dog’s chest to evaluate its heart size. An enlarged heart typically is working too hard.
Initially, this condition causes no obvious clinical signs, but as it progresses, there may be symptoms.
The initial symptom typically is a cough in the morning when your dog wakes up, or at night, when it gets excited or exercises.
This is a gagging-type cough, as if your dog has something stuck in its throat, and is a sign of fluid buildup in its lungs. If untreated, the cough eventually will occur randomly all day and night.
As untreated heart disease progresses, it can lead to other symptoms, such as difficulty breathing, fatigue, exercise intolerance, fainting or collapsing, loss of appetite, weight loss and/or abdominal swelling.
Any one of these signs means a trip to your veterinarian is crucial for diagnosis and treatment.
Your veterinarian will begin oral medications to help the heart work better and reduce fluid in the lungs.
The doctor may refer you to a canine cardiologist for an echocardiogram, which is an ultrasound of your dog’s heart. Click here to locate a veterinarian cardiac specialist in your area.
Not all heart murmurs in dogs indicate a serious problem. Some are completely harmless or benign.
These “innocent” heart murmurs do not typically require treatment.
According to recent research on the identification and clinical significance of heart murmurs in puppies, an average of 28% of puppies under 6 months of age have an innocent heart murmur.
That can rise to as high as 58% in puppies belonging to athletic breeds.
These puppy heart murmurs are usually not associated with any underlying heart disease or abnormality, Wiley says.
If a heart murmur persists as the puppy grows up or is accompanied by other symptoms, further evaluation and treatment may be necessary.
Giant breeds, like the Irish Wolfhound and Great Dane, and large breeds like the Doberman Pinscher, Golden Retriever and Boxer, can have higher rates of heart disease.
Smaller breeds, such as the Cavalier King Charles Spaniel, Dachshund, Miniature Poodle, Miniature Schnauzer, West Highland White Terriers, Beagles, English Bulldog, and Chihuahua also are more predisposed to heart disease.
Treatment of murmurs is based on the underlying cause. That might include regular monitoring of your dog’s heart with echocardiograms by a cardiologist, your veterinarian listening with a stethoscope, medications, specialized diets, or even surgery to correct certain heart defects.
The prognosis or expected outcome of the diagnosis also depends on the underlying cause. The heart murmur might have no impact on your dog’s health, or it could develop into congestive heart failure.
If untreated, it will shorten your pal’s lifespan but, if treated early on, will give your pal a good life.
