What is Heart Murmur in cats? Grades with Types

Heart Murmur in cats

The heart health of you and your pet should be a priority. Heart murmur in cats refers to the abnormal heart sound that the veterinarian usually observes by stethoscope.

If your cat has been diagnosed with a heart murmur, it’s important to stay calm and get informed.

There are many reasons why cats can develop this condition, and most of them are not cause for alarm. However, any underlying health issues must be timely identified and treated in order to protect your furry friend’s health.

It is difficult for a veterinarian to find the severity of the murmur only with the heartbeat. Therefore, they will follow a series of veterinary follow up and tests to find and diagnose the actual cause. 

This article is a comprehensive guide about Cat’s heart murmur and will cover any possible questions and topics related to this feline health issue. For ease, you can use the table of content.

What is Heart Murmur in cats?

Cat’s heart murmur refers to the abnormal heartbeat irregular “whooshing” sound associated with a disturbance of the smooth blood flow through the heart. Usually, a cat’s heart murmur is caused by the turbulent blood flow within the heart or its vessels.

Many reasons can cause this irregular heartbeat. Therefore feline heart murmur is not always a cause for concern. However, it can indicate any underlying health issues that must be timely diagnosed and treated. 

Grad 1-6 Cats Heart Murmur 

Based on the loudness of the heartbeat veterinarian has categorized this heart problem into six grades from Grade 1-6. Grade 1 is a minor concern, and Grade 6 is the most concern.

The grade of a heart murmur does not necessarily indicate heart disease and its severity. 

Grad 1 Murmur in cats: This Low-intensity heart murmur will only be heard in a quiet environment after careful auscultation over a localized cardiac area and can be observed with a stethoscope.

Grad 2  Murmur in cats: This Low-intensity murmur is heard immediately when the stethoscope is placed over the Point of Maximal Impulse PMI.

Grade 3 Murmur in Cats: This is a Murmur of moderate-intensity with abnormal heart rate.

Grade 4 Murmur in Cats: This is a High-intensity murmur that can be auscultated over several areas without any palpable precordial thrill.

Grade 5 Murmur in cats: The Grade 5 feline heart abnormal murmur is a  High- intensity murmur with a palpable precordial thrill.

Grade 6 Murmur in cats: High-intensity murmur with a palpable precordial thrill that may even be heard when the stethoscope is slightly lifted off the chest wall.

Types of Cats Heart Murmur

vet checking cat

To better understand, we have categorized this feline health issue into 5 types.

  • Innocent Kitten Murmur
  • Physiologic or Flow Murmur
  • Congenital Heart Disease
  • Systemic Disease
  • Heart Disease

Now, let’s elaborate on these heart-related issues in cats one by one.

1. Cats Innocent Heart Murmur

An innocent heart murmur is often found in young kittens below five months and may first appear at 5-8 weeks of age. If your kitty has a heart murmur, this doesn’t need to be a concern; however, if you observe that your kitty’s heartbeat is still murmuring after the age of 5 months, you need to contact your vet to diagnose the actual cause and to treat accordingly. 

2. Cats Physiologic or Flow Murmur

The Physiologic murmur of the heart is considered normal. This is a benign cause of a heartbeat and is not occur due to any structural heart disease.

3. Systemic Disease

in cats, heart murmur can also be caused by other Systemic diseases rather than heart disease, such as high blood pressure, hyperthyroidism, and anemia. Your vet can diagnose the actual cause by performing a series of tests. 

4. Congenital Heart Disease

Some cats’ irregular heartbeat can indicate any underlying Congenital Heart Disease. A cat suffering from any congenital Heart Disease will usually develop grade 4-6 loudness. This type of abnormal heartbeat needs proper and timely diagnosing and treatment by a professional veterinarian. 

5. Heart Diseases

Abnormal Heartbeat or a Heart murmur in felines is the leading symptom of heart-related issues such as Hypertrophic Cardiomyopathy HCM. These issues may lead your tom or queen to heart failure and can be fatal. 

What causes a Heart Murmur in cats?

Heart murmur in cats usually occurs due to many health issues such as turbulent blood flow within the heart, cardiac disease, Heart valve blockages, Blood clots, Extracardiac, Hyperthyroidism, Hypertrophic cardiomyopathy, Severe dehydration, Severe stress and fear.

In cats, the murmuring sound of the heart can be caused by many reasons. Some are considered normal, while for  some need to be concerned.

Symptoms of Heart Murmur in Cats

Below are some of the reported symptoms associated with a cat heart murmur. If you notice any of the below signs and symptoms in your kitty, make sure to contact your vet immediately to diagnose the actual cause of the irregular heartbeat.

Symptoms of Heart Murmur in cats are:

  • Increase or decrease in heart Beat
  • Irregular breathing and heartbeat
  • Weight Loss
  • Loss of appetite
  • Restlessness
  • Lethargy
  • Gray or blue gums
  • Stress and Anxiety
  • Collapse

Signs of heart irregular murmur in cats depending on the type and stage of the heart murmur issues. The symptoms can vary from cat to cat. 

How is Heart Murmur Diagnosed in cats?

Diagnosing the heart murmur

Diagnosing the heart murmur in kitties could be a difficult task for veterinarians. Usually, veterinarians hear two voices in the stethoscope: the “lub dub” sound of the heart valves and the second whooshing sound caused by the turbulent blood flow within the heart. This whooshing sound is known as a heart murmur. 

Your veterinarian may perform a series of tests to confirm the heart problem, including blood tests, Chest Radiographs,  echocardiogram, BP, and ECG. 

Heart murmur in cats Treatment

Treatment of cats heart murmur depends on the type of the disease and turbulent blood flow. Usually, the innocent and Physiologic feline heart murmurs do not require any treatment; however, a veterinary checkup is better to avoid any complications. 

Other causes of abnormal heartbeats, such as Congenital Heart Disease, Systemic Disease, and Chronic Heart Disease, will require proper and timely treatment. The treatment options for these heart abnormalities could be specialized diets, medications, supportive care, and even surgery. 

Cat Breeds that are more exposed to Heart Disease

Almost every cat can suffer from a heart murmur and other heart illnesses, but the below cat breeds are more exposed to heart diseases.

  • British or American Shorthair
  • Devon Rex
  • Maine Coon
  • Norwegian Forest Cat
  • Sphynx
  • Oriental Breeds
  • Persian
  • Ragdoll

No one want any harm or separation form its lovely pets. However some health issues may separate your pet from you. Pet urns are essential keep your pet in memories and will remind you the best memories you spend with your pets.

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If Knowing about your pet health condition is essential because sometimes there may be a problem that looks abnormal, but that will be normal and will no need of concern while on the other hand, there may raise some health issues that you consider minor, but that will need proper medical attention and could be fatal.

Your pet is more than just a responsibility, they are also your best friend. If you ever notice something unusual or concerning about their health condition then it’s vital that you talk to your veterinarian immediately 


How serious is a heart murmur in a Cat?

The severity of the heart murmur in cats depends on its type and cause. If your kitty’s heart murmur is due to an innocent or Physiologic murmur, then this is not serious.

However, if the reason for this abnormal heart rate is due to other feline heart problems such as Congenital or chronic heart disease, then it’s a serious threat and needs to be timely treated. 

Can stress cause a heart murmur in cats?

Yes, stress can cause a Physiologic murmur in cats. However, not all abnormal heart rate can be caused by stress or anxiety.

Sometimes your kitty murmur in the heart can indicate any underlying health issue or heart disease. So make sure to contact your vet if your notice a continuous abnormal heartbeat.

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