By Courtney Prue | February 9, 2024

Murmurs and Heart Disease in Cats

Causes, Symptoms, Treatments, Home Care and Life Expectancy

As a pet owner, it can be challenging to hear from your veterinarian that they found something abnormal on your beloved pet's health exam. This is particularly true if the diagnosis is related to an organ as vital as the heart. A heart murmur is one such abnormality that would understandably make your stomach drop, but what does it mean, and how concerned should you be? In this resource, we'll explore the causes, symptoms, and treatment options for heart disease in cats, and offer some helpful tips for managing this condition. We will also touch on quality of life and the value of palliative care, to keep your beloved pet comfortable for as long as possible.

What is a heart murmur in a cat? What does is mean that my cat has a heart murmur?

A heart murmur is an abnormal sound heard when listening to a cat’s heart with a stethoscope. Normally, a cat’s heart produces two distinct sounds: “lub” and “dub.” A heart murmur is an extra sound that can be heard between the two sounds, creating a “shooshing” or “whooshing” sound. This sound indicates turbulent blood flow through the heart. This turbulence can be created by any change to the normal smooth movement of blood through the heart. This includes narrowing, expansion, obstructions, other structural changes and changes to the consistency of the blood.

A heart murmur’s grade, ranging from 1 to 6, describes the loudness of the murmur. A grade 1 heart murmur is soft, while a grade 6 heart murmur is loud and can be felt by putting a hand on the chest. In cats, the grade of the murmur does not always provide information about the severity of the heart disease.


Are there different types of heart murmurs for cats? What is the most common heart disease in cats?

Heart murmurs can either be temporary and innocent or due to a ‘cardiomyopathy’, which refers to any disease that affects the heart muscle.

Temporary, innocent murmurs do not impact a cat’s health; the murmur usually goes away when the underlying reason has been addressed or changed.  Certain things cause the heart to work harder, causing increased turbulence and, therefore, a murmur. Some of these conditions can impact the health of the cat, but the murmur itself is not necessarily a concern. This includes when they are:

    • Kittens, up to 6 months of age
    • Stressed or anxious
    • Low red blood cells (anaemia) or low protein (hypoproteinemia) in the blood
    • Pregnant
    • Feverish
    • Have hyperthyroidism (Note: long-term uncontrolled hyperthyroidism can cause irreversible damage to the heart)

Cardiomyopathies (heart disease) are irreversible and can progress in severity over time, with the potential to greatly impact a cat’s health. Types of heart disease include:

      • Hypertrophic Cardiomyopathy (HCM): HCM is the most common form of heart disease in cats, accounting for 80-90% of all cases. It is characterised by the thickening of the heart muscles, making it difficult for the heart to pump blood effectively.
      • Dilated Cardiomyopathy (DCM): DCM is characterised by the weakening of the heart muscles, which leads to the heart becoming enlarged and less able to pump blood effectively.
      • Other rare types include Restrictive Cardiomyopathy (RCM), Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) and Mitral Valve Disease (MVD)

What causes heart disease in cats? What caused my cat’s heart disease?

    • Genetics: Some breeds of cats, such as Maine Coons and Ragdolls, are more prone to developing heart disease.
    • Age: As cats get older, their risk of developing heart disease increases.
    • Diet: Diets deficient in vital vitamins and amino acids can lead to Dilated Cardiomyopathy. Commercial diets are balanced to include everything needed to support a healthy heart.
    • Underlying health conditions: Diseases such as hyperthyroidism, hypertension, and kidney disease can increase the risk of heart disease.

What are the signs of heart disease in cats? How can I tell if my cat has heart disease?

The symptoms of heart disease in cats can vary depending on the type and severity of the condition. Some common symptoms include:

      • Lethargy or weakness
      • Decreased exercise tolerance
      • Difficulty breathing
      • Rapid breathing or panting
      • Loss of appetite
      • Weight loss
      • Coughing or gagging

If you notice any of these signs, book a consultation with your veterinarian to discuss possible causes and perform any indicated diagnostics.


Can my cat have a heart attack? Can my cat die suddenly with heart disease?

It is important to know the symptoms that indicate a medical emergency in cats with heart disease, as prompt veterinary attention can be life-saving. Here are some symptoms to watch out for:

      • Difficulty breathing: This can manifest as panting, open-mouthed breathing, or rapid breathing. If your cat is struggling to breathe, it is a medical emergency.
      • Bluish or pale gums: This can be a sign of poor oxygenation and should be evaluated by a veterinarian immediately.
      • Weakness or collapse: This may indicate poor blood flow to vital organs and requires immediate veterinary attention.
      • Sudden onset of paralysis: This can be a sign of a blood clot, which can be a life-threatening complication of heart disease.
      • Loss of consciousness: This can occur suddenly and may be a sign of cardiac arrest, which requires immediate cardiopulmonary resuscitation (CPR).

If you observe any of these symptoms, seeking immediate veterinary attention is important. Time is critical in emergency situations, and a delay in treatment can have serious consequences for your cat’s health. Don’t hesitate to call your veterinarian, our team or an emergency veterinary clinic for guidance on how to proceed.


What are the side effects of heart disease in cats? What other complications can my heart disease cat get?

Heart disease can have significant impacts on other parts of the body. Such impacts include:

      • Congestive heart failure: This occurs when the heart is unable to pump blood effectively, leading to a backup of fluid in the lungs and other organs. Symptoms may include coughing, difficulty breathing, and lethargy.
      • Blood clots: Heart disease can cause the formation of blood clots in the heart, which can travel to other parts of the body and cause serious damage. This is known as thromboembolism and can cause sudden pain and paralysis in the hind legs.
      • Arrhythmias: Heart disease can cause abnormal heart rhythms, or arrhythmias, which can be life-threatening if left untreated.
      • High blood pressure (hypertension): The body can compensate for an inefficient heart by increasing the blood pressure, which can cause secondary damage to other organs

How is heart disease diagnosed in cats? How will the vet investigate my cats heart murmur?

Diagnosing and monitoring heart disease in cats typically involves:

      • Physical exam. Your vet might recommend a recheck in 1-3 months to see if the murmur is still present, or if it was temporary.
      • Blood tests, including testing thyroid hormone levels
      • Imaging tests such as X-rays, echocardiography (heart ultrasound), or electrocardiography (electrical activity monitoring)
      • Blood pressure tests

These tests will determine how severe the heart disease is, what type is occurring, how it is progressing and help direct treatment efforts.


Can heart disease in cats be treated? How can my cats heart disease be treated?

The treatment options for cats with heart disease depend on the severity of the condition, and are aimed at reducing the risk or impact of the most common complications. Treatment options include:
      • Medications: There are several different types of medications that can be used to treat heart disease in cats, including
        • Diuretics to help remove excess fluid from the body
        • ACE inhibitors to help dilate blood vessels and reduce blood pressure
        • Beta-blockers to slow the heart rate and reduce the workload on the heart
        • Antiplatelet or anti-coagulants to reduce the risk of clot formation
      • Specialised diets: Some cats with heart disease may benefit from a special diet that is low in sodium and high in certain nutrients, such as taurine and L-carnitine.
      • Oxygen therapy: If the cat is having difficulty breathing, oxygen therapy may be necessary to provide additional support.
      • Surgery: In some cases, surgery may be necessary to correct certain types of heart disease, such as a congenital defect. These will involve a referral to a specialist veterinary hospital.
The medical management and monitoring of heart disease can be confusing and overwhelming. Get in touch with your regular veterinarian or our team today for a personalised discussion.  

How do I manage my cat’s heart disease at home? How can I help my heart disease cat at home?

Here are some tips to help you optimise your cat’s care at home:
      • Monitor your cat’s breathing: This includes the effort used, as well as the rate. An important factor to monitor is their resting respiratory rate. While deeply asleep, count the number of breaths taken in 1 minute (or in 15 seconds and then multiply by 4). The rate should be between 10-20. If it is over 30 breaths per minute, ring the vet ASAP as this indicates possible congestive heart failure.
      • Create a comfortable living space: Ensure your cat’s living space is warm, quiet, and comfortable. Provide soft bedding, and ensure the area is clean and free of drafts.
      • Manage stress: Stress can worsen your cat’s heart disease. Try to minimize stress by keeping their routine consistent, minimizing loud noises, and providing a calm environment.
      • Regular check-ups: Your vet will monitor your cat’s condition and make changes to their treatment plan as necessary.
An in-home veterinary assessment can also be helpful to identify any other areas of improvement, that can help your beloved cat stay comfortable for as long as possible.    

How long can my cat live with heart disease?

The prognosis for cats with heart disease varies depending on the type and severity of the condition, as well as the cat’s overall health and response to treatment. Some cats may be able to live for several years with appropriate treatment and care, while others may experience a more rapid decline in health.

End-of-Life Care Tips:

If your cat’s heart disease has progressed to a point where treatment is no longer effective or its symptoms are too severe, it’s important to consider end-of-life care options, including possibly putting your cat to sleep (euthanasia).  This can be an overwhelming and distressing thing to even think about.  Your regular veterinary clinic and our team at Rest Your Paws are here to support you and provide compassionate care for your beloved pet throughout their journey.

Here are some end-of-life care tips for cats with heart disease:
      • Keep them hydrated and well-nourished with some delicious food
      • Spend quality time with them, making the most of every moment, such as with a bucket list
      • Offer a calm and peaceful environment, free from stressors that can exacerbate symptoms
      • Provide a warm and comfortable space for your cat to rest and sleep, with easy access to food, water, and litter box
      • Administer medications as prescribed for pain management and symptom relief. Your veterinarian may increase doses of medications such as diuretics to reduce fluid accumulation.
      • Monitor your cat’s breathing, heart rate, and overall condition, and seek veterinary attention if necessary
      • Evaluate their Quality of Life regularly or contact a palliative care vet to help you
      • Consult our End of Life Care Pack to get prepared to put your dog to sleep
      • Track good days and bad days on our Quality of Life Assessment Calendar

Heart disease in cats is a serious and complex condition that requires attentive care and management. With appropriate treatment and end-of-life care options, many cats can live for several years with a good quality of life. By understanding the causes, symptoms, diagnosis, treatment, and end-of-life care options for heart disease in cats, pet owners can make informed decisions and provide the best possible care for their furry companions. 

We understand this is a challenging time for you and your family. Reach out to your regular veterinary clinic or our team for the guidance and care you and your furry friend deserve. If you want to learn more about putting your pet to sleep, cat euthanasia at home, options to put your pet down at home, costs of euthanasia at home or what it looks like to put your pet to sleep at home, speak to your vet, call us on 0422 157 675 or visit our website.


We offer in-home palliative care and euthanasia for cats and dogs 7 days a week across Australia. Support your beloved pets in comfort and say goodbye with peace and dignity with professional and experienced end-of-life support.

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