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What is heart disease in cats?

Heart disease in cats most commonly occurs because of changes to the muscle within the heart, and this is called a cardiomyopathy. There can be different types of cardiomyopathy, depending on how the muscle is affected, but the symptoms are often similar. Heart disease is more common in middle aged or older cats, but occasionally occurs in younger cats, and kittens can be born with heart defects.

Hypertrophic cardiomyopathy (HCM)

This is the most common heart disease in cats. The heart muscle becomes thickened and as a result the space within the heart (the chambers) get smaller. This can prevent the heart muscle properly filling and then pumping the blood around the body. It can be inherited in some breeds of cat, caused by other diseases, or happen with no known reason (which is called ‘idiopathic’).

Other cardiomyopathies

There are other types of cardiomyopathy, but these are rarer. Dilated cardiomyopathy causes the heart muscle to thin and become floppy, and restrictive cardiomyopathy causes scar tissue to stop normal muscle movements.

Symptoms of cat heart disease

Many cats with heart disease won’t have any symptoms. If heart disease progresses, there can be different signs depending on the individual cat and the type of heart disease they have. Early changes, such as being less able to exercise, can be more easily missed in cats. The most common symptoms in cats are breathing difficulties (either fast breathing or more laboured breaths) and having less energy. Other possible symptoms include:

  • behavioural changes or hiding
  • eating less
  • weight loss
  • collapsing
  • swollen belly
  • loss of use of the legs or severe pain
  • cold extremities
  • pale gums

Many of these signs can be caused by other diseases too. Remember, if you notice any changes to your cat’s health or behaviour you should always call your vet to get them checked over. If you’re worried your cat has heart disease, take them to the vet as soon as possible, many of the symptoms of heart disease in cats require emergency care.


What is a heart murmur? Is it a sign of heart disease?

A murmur is the name given to an unusual sound made by the blood moving through the heart. It is described as a whoosh sound.

Heart murmurs are common in cats. Although a murmur may be a sign of a problem, around one half of cats with a heart murmur don't have any underlying heart disease and of those that do, many live quite normally without ever developing any signs of that disease. A number of cats who do have significant heart disease do not have a heart murmur, meaning that many cases of heart disease remain undetected.

How is heart disease diagnosed?

If your vet thinks your cat may have heart disease, they might recommend the following tests:

  • blood tests – a general health screen looks for other diseases which may be present or contributing to heart disease. Specific tests can measure substances released into the blood when there are changes to the heart muscle wall
  • blood pressure measurement
  • electrocardiography – assesses the electrical rhythm of the heart
  • echocardiography – ultrasound is used to visually assess the heart and take measurements. This is the best way to assess heart disease

How is heart disease in cats treated?

Unfortunately, there’s no cure for heart disease in cats and for most types of heart disease there aren’t treatments to slow progression.

Sometimes your cat may only need monitoring, depending on the type of heart disease they have. Your vet may prescribe certain medications and they will give you advice on managing your pet’s condition.

Make sure to give your cat any medication your vet prescribes.

How do cats get heart disease? Can I prevent my cat getting it?

Most often, heart disease is not preventable and the cause is not known. However, conditions such as hyperthyroidism, high blood pressure, infections, diseases like and heart defects can also cause heart disease in cats. While you can’t necessarily prevent heart disease, taking your cat for regular check-ups with the vet will mean any issues are picked up early.

Certain breeds (such as Maine Coons and Ragdolls) may inherit heart conditions from their parents. Screening before breeding these cats is recommended.

Dilated cardiomyopathy used to be more common and was caused by cats not getting enough of the essential amino acid taurine in their diet (it is found in animal protein). Feeding your cat a complete diet can greatly reduce the chance of a cat getting this type of heart disease. Find out more about feeding your cat.

How long do cats with heart disease live?

How long cats live with heart disease depends on what type of heart disease they have, if they have other conditions contributing to the heart disease, and what progression or complications occur. For example, a mild type of heart disease might mean your cat can still live a full and happy life. However, more severe heart disease may mean your cat needs much closer monitoring and treatment for their heart disease and this often sadly will shorten their life expectancy.

What is heart failure in cats?

Heart failure can occur as heart disease progresses. Cats don’t suffer from ‘heart attacks’ like humans. Instead, their hearts can fail when the severity of their heart disease has reached a point where the body can no longer cope.

Heart failure is therefore a result of having heart disease. However, predicting when or if heart disease will develop into heart failure isn’t always possible.

Symptoms of heart failure in cats

The symptoms of heart failure are very similar to the symptoms of heart disease in cats, which you can read above, but you may also notice:

  • their ears and paws are colder as their heart struggles to pump blood to them
  • weakness
  • weight loss
  • struggling to use their back legs (this is due to blood clots forming and can be very painful for your cat)

If you’re worried about your cat, make an appointment with your vet as soon as possible.

Can heart failure in cats be treated?

Your vet may discuss treatments which can help the symptoms of heart failure but it sadly cannot be cured. Treatments will depend on your cat’s circumstances, so discuss options with your vet as they can advise the best course of action.

Are heart disease and heart failure painful for cats?

Certain side effects of heart disease can cause your cat pain, such as if a blood clot forms or if fluid builds up in their chest. Cats are very good at hiding when they are in pain so it’s important to make sure you take them to the vet if they show any signs of discomfort straight away. Your vet will be able to recommend treatments and medication to alleviate your cat’s pain.

If your cat’s heart disease progresses into heart failure, there may come a stage when your cat’s quality of life is affected, and you may have to discuss the possibility of putting them to sleep. You can read our page on when to put your cat to sleep for more advice.

How to tell if your cat is in pain

For more information on heart murmurs and heart disease, download our leaflet:

Download our guide on heart disease
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