Heart Murmur in Dogs: Symptoms, Causes and Treatment Guide
Has your dog just been diagnosed with a heart murmur? While it can be alarming to hear, heart murmurs are quite common in dogs, especially as they age. Understanding what a heart murmur is, what symptoms to watch for, and when to seek treatment can help you make the best decisions for your furry friend’s health. In this comprehensive guide, we’ll explain the types, causes, symptoms, and treatment options for heart murmurs in dogs, so you can feel confident and prepared to care for your pet.
Table of Contents
What is a Heart Murmur?
A heart murmur is an abnormal heart sound or vibration caused by disturbed blood flow inside the dog’s heart.
This rhythmical lub-dub or whooshing noise can be heard through a stethoscope. The turbulent flow of the blood is the main reason behind this audible sound. When the blood flows fast through the abnormal heart valves or across abnormal structures within the heart, you can hear and feel this sound (a swoosh noise – swoosh-dub, swoosh-swoos) when you lay your hand over your dog’s heart.
So you might be wondering, what’s the big deal with this sound? Does it affect your dog’s health much?
The answer is yes! That’s because sound is actually a major symptom of another underlying medical problem.
How To Identify a Heart Murmur in Dogs?
The vet finds heart murmurs by listening to your pet’s heart with a stethoscope. Sometimes an echocardiogram (ultrasound of the heart), which is a type of non-invasive test, is performed to find the real cause of the murmur.
Your veterinarian will listen for:
- Loudness – This is determined by the amount of turbulence taking place in the dog’s heart.
- Location – Exactly where the murmur can be heard the loudest.
- Timing – It’s important to determine the right timing when the murmur happens.
- Length – This will determine how long the murmur lasts through the heart cycle.
Types of Heart Murmur in Dogs
On the basis of the sound which is heard during the heart cycle, Veterinarians has classified heart murmur into three categories:
- Systolic murmur – this occurs when the heart contracts
- Diastolic – occurs in between beats
- Continuous – occurs throughout
Systolic heart murmurs occur during the systole phase, and this is the one that most canines suffer through. On the other hand, Diastolic murmurs are rarely found in dogs. Continuous murmurs, which are also known as to-and-fro murmurs, generally happen throughout the regular cardiac cycle of a dog’s heart.
Grading Scale for Heart Murmurs in Dogs
Now you know that not every heart murmur is the same, as they sound differently. They can be different by intensity and loudness, which is generally determined by the amount of disturbance present in the heart. Here are some ways to help a dog suffering from chronic boredom that you must know.
So, when to worry about a heart murmur?
Veterinarians grade the heart murmurs in Dogs on a scale of 1 (mild) to 6 (severe). Here’s the murmur grading:
- Grade 1: Barely audible
This is the least serious type of heart murmur, which is also the least audible.
- Grade 2: Soft murmur
This is soft and quiet but can be heard with a stethoscope
- Grade 3: Intermediate loudness
This grade of heart murmur has an intermediate volume that is consistently heard. This is a symptom of serious health problems.
- Grade 4: Loud murmur
This murmur can easily be heard on either side of the dog’s chest.
- Grade 5: Very loud murmur
A heart murmur of this grade can easily be heard with a stethoscope or felt by placing your hand on the chest.
- Grade 6: Very loud murmur
You can feel this murmur when you place your hand on the dog’s chest, and this is the most severe type of heart murmur.
Configurations for Heart Murmurs in Dogs
The heart murmur configuration, also known as the quality of the murmur, is basically the way of murmur sounds. Veterinarians describe four types of heart murmur configurations:
- Plateau murmurs
- Crescendo-decrescendo heart murmurs
- Decrescendo heart murmurs
- Continuous murmurs (machinery quality murmurs)
Symptoms of Heart Murmurs in Dogs
Now you know what a heart murmur is, its types, and grading with configuration, let’s move on to the heart murmur symptoms in dogs.
Surprisingly, most canines don’t show any signs of illness, whereas some show.
Some of the most common symptoms of heart murmur include:
- Irregular heartbeat
- Weakness or lethargy
- Hacking, persistent cough
- Excessive panting even when resting
- Tires easily
- Lack of energy
- Distended abdomen or bloated appearance
- Collapses or faints
- Gums and/or tongue are bluish in color
- Racing pulse
- Pale gums or mucus
- Lack of appetite
- Severe water retention
Note:
The above symptoms are seen in adult dogs. Whereas in puppies, you can determine these health issues by noticing their growth. A puppy suffering from a heart murmur will be thinner and smaller than other pups their age.
Causes of a Heart Murmur in Dogs
The basic cause of a heart murmur varies. For example, it can be caused by either actual damage to the heart or medical conditions that are not even related to the heart.
On that basis, murmurs are determined as “innocent” or “physiologic” and sometimes pathologic as they occur because of some structural problem within the heart (cardiac disease).
Heart murmurs can also be caused by the dog congestive heart failure or abnormal stretching of the heart muscle, faulty valves, narrowing of the veins or arteries, dilated heart chambers, holes in the heart walls, tumors, other structural abnormalities. These all things create blood turbulence which results in a heart murmur. Here you can also read about Melatonin for Dogs.
However, suppose a murmur is caused by a medical condition that is not related to the heart. In that case, they’re usually quiet and intermittent, and this can easily be resolved after getting the right treatment.
Here is a list of conditions that can cause heart murmur in dogs:
- Anemia
- Atherosclerosis
- Cardiomyopathy
- Dysplasia
- Endocarditis
- Endocardiosis
- Heartworm disease
- Hyperthyroidism
- Pulmonic stenosis
- Other valvular stenosis
- Tumors
- Tetralogy of Fallot
Continuous or To-and-Fro Heart Murmurs
The following reasons cause this type of heart murmur:
- Patent ductus arteriosus
- Ventricular septal defect with aortic regurgitation
- Aortic stenosis with aortic regurgitation
Diastolic Heart Murmurs
The following medical conditions cause this type of heart murmur:
- Mitral and tricuspid valve stenosis
- Aortic and pulmonic valve endocarditis (inflammation of the inner layer of the heart)
Heart Murmur in Dogs: Treatment & Investigations
See, Vets do not treat the heart murmurs in dogs directly! The proper treatment depends on the cause of the dog’s murmur. For example, if your dog has a grade 1 or grade 2 heart murmur, they usually don’t need any treatment.
First, the vet will identify the underlying causes, and according to that, they give the proper treatment. This can be simple as a few dietary changes to medication and surgery for severe heart murmurs.
If your dog is suffering from a loud murmur or seems unwell, they may suggest tests and investigations such as:
- X-rays
- An ultrasound scan
- An ECG (a heart trace)
- Blood tests
The Bottom Line
Heart murmurs in dogs are a sign of underlying diseases. Sometimes with the simple treatment and medication, it can be treated, but sometimes they need surgery if it is caused by serious heart problems.
That’s why some dogs show symptoms of a heart murmur like difficulty in breathing, weakness, and cough, while some dogs don’t show any signs. That’s why it’s vital to get regular check-ups at the vet. The doctors can easily catch heart murmurs through your routine visits.
So, if you think that your dog may be suffering from a heart murmur or you have any health concerns about your dog’s heart, please visit your vet without hesitation! They clarify all your doubts and questions about heart murmur in dogs and provide your dog with the right treatment.
I hope this in-depth guide on heart murmur in dogs has provided you with all the information you need. So, if you find this blog informative and helpful, please share it with your friends and family.
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