My heart beats dog™ and after my dog was diagnosed with a heart murmur, that rhythm went a bit out of sync but never stopped. If you are looking for information about dogs with a heart murmur and how to help them, that is the focus of this article.
First and foremost, a heart murmur in a dog is not a death sentence. As a lifelong dog mom and dog parent to two Cocker Spaniels with a heart murmur, dogs can and do live long, healthy lives with a heart murmur.
What is a Heart Murmur
The heart is designed to pump blood through the body of a dog, just like ours. A heart murmur in dogs is often detected during a standard veterinary visit. In fact, many dog parents are unaware their dog has a murmur until the vet makes the diagnosis. I know because this has been the case twice for me and my dogs, both Cocker Spaniels.
A murmur is a disturbance in the flow of blood through the heart. When the flow of blood is any some way compromised, the noise is heard on auscultation by a veterinarian. That noise is audible to the vet and is called a murmur.
What are the Signs of a Heart Murmur in Dogs
Sometimes there are no symptoms, as is the case with my dogs. In other cases, there are signs or symptoms of a heart murmur.
According to petMD, “The symptoms associated with murmurs depend on a variety of characteristics, including their grade, configuration, and location. If, however, the murmur is associated with structural heart disease, your dog may display signs of congestive heart failure such as coughing, weakness, or exercise intolerance.”
A dog may also have a pale or bluish tinge to his gums, so gum and oral cavity inspection must be a part of your 10 touches to do every week on your dog.
Any time your dog’s abdomen appears large or distended, this is a cause for concern as it may be fluid retention due to a heart problem. Does the dog pant heavily at rest? Does he ever have fainting spells? These are reasons to seek veterinary care as soon as possible.
Any time a dog develops a cough, this is something to be investigated by your dog’s veterinarian. There are many reasons for a cough and the presence (or absence) of a cough does not necessarily mean a heart murmur.
How is a Dog Heart Murmur Diagnosed
As stated above, normally the initial diagnosis of a canine heart murmur is done at the veterinarian’s office and with a stethoscope.
There are things that can actually make a murmur sound as if it is present, but in actuality it is not there. If a dog is hyper or excited at the vet, this may not be the best time to listen to the heart.
Hearing a murmur is the first step, but hearing the loudness of the murmur and then determining where the sound is coming from and the type/grade of murmur is next. Knowing the grade and type of murmur will help the vet try and diagnose a cause.
Veterinary cardiology is growing specialty, and an option that you can consider if your veterinarian does not have the equipment (echocardiogram) to assess your dog and develop a long-term treatment plan.
Personally, we are fans of having a specialist handle the system-specific ailments of our dog while keeping our general veterinarian in the loop. Either way, having a qualified medical professional both diagnose and treat the murmur is important.
Grading of Canine Heart Murmurs
Like people, once a murmur is identified, the veterinarian or veterinary cardiologist will both grade and stage the murmur.
Murmurs are grade on a scale of one to six (I to IV), as outlined by the AKC:
- Grade I murmurs are the least serious and are barely detectable with a stethoscope.
- Grade II murmurs are soft, but your veterinarian can hear them with the help of a stethoscope.
- Grade III murmurs have a loudness that falls in the middle of grades II and IV. Most murmurs that cause serious problems are at least a grade III.
- Grade IV murmurs are loud and can be heard on either side of the chest.
- Grade V murmurs are very loud and can be heard with a stethoscope without difficulty, and can also be felt by holding a hand against the dog’s chest.
- Grade VI murmurs, like grade V murmurs, are very loud and can be felt through the chest wall, and are the most severe of the heart murmurs.
What Tests Are Performed After Heart Murmur Diagnosis
As a dog mom with a dog who has a grade one to two heart murmur, we went the route of further testing and followup. Knowing that a heart murmur exists and with a grade designation, the next step is testing.
Determining the severity of the murmur, getting a visual inspection of the cardiovascular structures, and running some tests provides a total picture to determine an action plan. There are many reasons and causes for heart murmurs and also several types of murmurs, which testing will determine.
Tests to consider for the dog with a heart murmur include, but are not limited to:
- Chest x-rays: Shows the trachea, size and shape of the heart, and looks at the lungs, blood vessels, and bones in the area. If there is any fluid or air in the lungs, enlargement of the heart, air in the chest cavity, tumors, or fractures, a chest x-ray will determine if they are present.
- Doppler studies: This involves an ultrasound of the heart. The direction and speed of blood flow in the heart and blood vessels are measured with Doppler studies. If the veterinarian has access to color-flow Doppler technology, the observation of flow of blood through the heart and blood vessels is easier to see.
- Echocardiogram: This is a sonogram of the heart, generally without a sedative and involves no radiation. The goal of an echocardiogram is to assess the condition of heart and detection of anything abnormal.
- Blood work: According to petmd, a CBC (complete blood count) is one of the preferred methods for confirming anemic murmurs. Karen Becker over at Healthy Pets says writes that there is a blood test that measures the amount of stretching the heart muscle is undergoing, called a proBNP blood test.
Here is the result of our dog’s echocardiogram and radiographs of the chest from the time of his diagnosis in May of 2017:
What Causes Canine Heart Murmurs
If the problem is congenital, as is sometimes the case in puppies diagnosed with murmurs, it can be a familial issue. There are whole host of reasons for a canine heart murmur, which is why further testing can help.
The heart murmur is indicative of some underlying problem, so identifying that problem is important for management. Some causes of a heart murmur in dogs include, but are not limited to:
- Degenerative valve disease, common in older and smaller breeds of dogs. Our dog was diagnosed with degenerative mitral valve disease, which we are managing conservatively with observation and testing.
- Flow murmurs, which means no structural disease is present
- Heart muscle disease leading to poor pumping function
- Anemia (correcting this may eliminate the functional heart murmur)
- Low protein levels in blood (hypoproteinemia)
- Fever or infection
- Obesity (solving this issue may help the murmur!)
- Worms/parasites/fleas/ticks: When my dog was diagnosed with an immune system disease (IMT), the murmur was heard because his platelets on admission to the hospital were zero!
- Bacteria from uncared for teeth can contribute to cardiac disease, which is why is imperative to have a dog dental care plan in place. Bacteria from uncared for mouth is scientifically linked to heart valve infections in dogs!
There are many other reasons for a heart murmur, but as you can see, a murmur may affect one dog a certain way and another dog in a completely different way depending on the cause.
Are Some Dog Breeds Prone to Heart Murmurs?
Yes, and the table below identifies some dogs that are at greater risks (Mercola.com).
This does not mean that if your breed of dog is on the list that the reason for the murmur is exactly as listed. This is a general guideline to help your veterinarian in treating your dog, knowing some breeds are more prone than others.
What is the Treatment for a Dog with a Heart Murmur
Most surprising is the murmur is not treated, and the cause for the murmur may or may not be treated.
There are always options, and this is something for which we advocate at Fidose of Reality. A canine heart murmur is not a death sentence. The fear of hearing “heart murmur” is upsetting, and I know this first hand. Dealing with the underlying cause is the goal for most dog parents, and the factors consider include:
- Finding a board certified veterinary cardiologist. The vet who first diagnosed my last Cocker Spaniel with a heart murmur ended up being, well, wrong. We took my dog to a university hospital to a board certified veterinary cardiologist and received a clean bill of cardiac health. Years later, she developed a grade 1 murmur, which never progressed.
- Medications: Depending on the issue, standard medication for heart issues may be prescribed. Over at petMD, Dr. Jennifer Coates shares, “If the patient already suffers from CHF, standard treatment (e.g., enalapril, furosemide, and pimobendan) for that condition should be started immediately.
- Discuss supplements that may help your dog with their condition. A holistic vet can help with this. A holistic vet can work in tandem with your regular and/or cardiac veterinarian. Supplements for dogs with heart problems run the gamut from omega-3 essential fatty acids to krill oil and Chinese herbs. Never attempt to add something without the guidance of a skilled professional in veterinary medicine, as doing so can actually make the heart condition worse.
- Followup care: Your dog’s vet or cardiologist will determine a schedule for followup testing and the types of tests to perform. In our case, we will repeat an echocardiogram and chest x-ray with regular blood work this year. Since our dog has an immune system disease in remission, his blood panels are being checked monthly by a specialist.
- Some congenital heart defects can be surgically corrected – these include pulmonic stenosis and patent ductus arteriosus, according to VCA Hospitals.
Each dog is different, so prognosis and treatment is based on your dog’s individual testing and condition. Regular followup and close observation of your dog’s behavior are two crucial elements to cardiac care.
BONUS TIP: Keep a canine observation journal and note any changes with the dates in the journal to report to your vet. Knowing what normal is in your dog is helpful with reporting anything out of the ordinary.
I’ve learned to take my dog’s vital signs and suggest Fidose of Reality dog parents do the same.
CLICK THIS: How to Take Your Dog’s Vital Signs
Prognosis of Canine Heart Murmurs
The prognosis of a canine heart murmur varies from dog to dog from excellent to grave. It all depends on the reason for the murmur and along with any other conditions or ailments the dog has. Is the dog being treated for a condition at present? Is he overweight? Does he get fed a quality diet and given exercise under veterinary guidance? Does he get regular check ups and blood work?
If surgery is an option based on the dog’s cardiac issues, this improves the prognosis. If medications can help, again this helps the long-term prognosis. VCA Hospitals share this very helpful tidbit:
If the murmur is caused by extracardiac disease or a functional problem that can be treated, the murmur may resolve over time. The long-term prognosis for a dog with a murmur caused by congenital heart disease is extremely variable, depending on the specific type of defect that is present; if the defect can be surgically corrected the prognosis is very good. A dog with mitral insufficiency can usually be managed with long-term medications. The prognosis for a dog with dilated cardiomyopathy varies – if the dog is showing symptoms of heart failure the prognosis will be grave. The prognosis for a dog with bacterial endocarditis will vary with the severity of the infection and the valve that is affected. The need for good dental care, including regular professional dental cleaning under general anesthesia cannot be overemphasized as a means of preventing endocarditis.
A heart murmur is not an automatic death sentence. You are your dog’s advocate, so have an open discussion with your dog’s veterinarian about restrictions, signs to watch for, when to call for an appointment, and what is considered a cardiac emergency.
Dogs Who Have a Heart Murmur
Three dog moms, each who have a dog with a heart murmur share their feelings about dealing with this condition in their dog.
Aimee Beltran, founder of the popular Irresistible Pets and Irresistible Icing blogs, says, “I took Chuy, my Chihuahua to the emergency vet to get antibiotics for a skin infection that wouldn’t go away.”
She continues, “During the appointment, the ER vet noticed a mild heart murmur while taking his vitals. My heart sank and I had hundreds of questions. They recommended an EKG within a year. Me, being a proactive and overprotective dog mom booked the first available appointment. I was in tears the entire way home as I had no idea what this would mean for my Chuy. I decided I had to empower and arm myself with as much information as possible.”
The diagnosis for Chuy is degenerative valve disease leading to mild mitral regurgitation. This is classified as a mild B1 heart murmur.
Beltran says this means that nothing changes for him right now other than to keep an eye out for symptoms such as shortness of breath, coughing, and general fatigue while on walks. She will have him re-checked in a year. She is grateful the emergency vet found the murmur so that she can be proactive in helping Chuy live his best self and longest life.
My dog, Dexter, was diagnosed with a low-grade heart murmur by a veterinary friend. His results, as shown above, are that of degenerative mitral valve disease we will monitor with testing. The veterinarian who performed the echocardiogram called me to report that Dexter’s overall prognosis is very good. There were no changes to the heart and the mitral valve is slightly thickened. He does have mitral valve disease, mild, that we will monitor with testing.
We had his thyroid panel checked and at this time, no therapy is recommended. We did, however, implement a weight loss plan since our Dexter put on some winter weight last year. Dropping five pounds has been very healthy for our dog and we look forward to another healthy heart report. We are to watch for any sudden changes in health and keep our followup appointment, which of course, we will.
Dog mom, Cheryl Engel, has a 14-years-young Cocker Spaniel, Sophie, who wears a Holter monitor for dogs from time to time.
Engel says, “Sophie has a murmur, mitral valve disease, and 2nd degree AV block with low heart rate that cause her heart to stop for as long as 5.9 seconds while she sleeps. She takes medications every eight hours to increase her heart rate. She is almost 14 and doing pretty good.”
In terms of ongoing care and frequency in wearing the Holter monitor, Sophie’s cardiologist has her wear it for 24 hours every six months to monitor her heart rate at home and while she sleeps. She also gets an echocardiogram every 6 months to a year. She has always had the murmur, Engel shares, “but the other stuff was found about five years ago when my vet sent us to the cardiologist before a dental to make sure she could handle anesthesia. ”
At that time Sophie was able to undergo the dental cleaning with atropine to speed up her heart, but now it would be very risky. She is on the maximum dose of Levsin 3/4 pill at three timesa day and hasn’t had any collapsing spells since last spring.
A pacemaker is an option for Sophie, Engel tells us. “We talked about a pace maker but the meds are doing okay and with her age the recovery is scary. Knock on wood she is doing good and still has spunk between naps.”
Can Dogs Have a Heart Valve Replacement?
If a faulty heart valve is causing cardiac issues for a dog, can it be repaired or replaced as is the case for their human counterparts?
In an article for Veterinary Information Network, it is shared that “Mitral valve repair surgery won’t be available in the United States any time soon, but Dr. Simon Swift, medical director of the small animal hospital at the University of Florida’s College of Veterinary Medicine, mentions in the 2016 piece that UF has a three-year plan to make it available.”
That said, the family interviewed for the piece in VIN left the country to have a cardiologist overseas perform the surgery on their Cavalier King Charles dog with success. You can read more about this mitral valve surgery on the dog.
According to the Colorado State University Veterinary Teaching Hospital, canine mitral valve disease accounts for 75 percent of heart disease in dogs, affects between five and seven million dogs in the United States, and is the leading cause of death and disability in dogs. Not all dogs with canine mitral valve disease will succumb to it. Keep this in mind.
There are other surgeries include an MVP, mitral valve repair, which is a relatively new surgery. At the Michigan State University Veterinary Medical Center, they have been performing heart surgeries for a number of years.
At Cornell’s Hospital for Animals, a Japanese Chin received a rare and successful seven-hour open-heart surgery. Located in New York, and as a former patient at the hospital, Cornell’s Cardiology Companion Animal services provide, “a number of interventional therapies including, but not limited to, pacemaker implantation, occlusion of patent ductus arteriosus, balloon valvuloplasty for pulmonic and subaortic stenosis, cardioversion of atrial fibrillation and radiofrequency catheter ablation of arrhythmias.”
Yes, there are things that can be done, from medications to dietary adjustments, surgeries to various treatments.
You are your dog’s advocate, there are things that can be done to diagnose, monitor, treat, and sometimes repair the problem that is causing the heart murmur.
Our friend, former veterinary technician, Rachel Sheppard of My Kid Has Paws, gives her take on heart murmurs in dogs. Be sure to visit and see what she has to say.
Has your dog ever had heart issues??? Let us know in the comments below. We respond to everyone!