A Complete Guide to Heart Disease in Cats

Heart disease in cats refers to any condition that impairs the structure or function of the heart. It can be congenital (present from birth) or acquired later in life. Unlike in dogs, feline heart disease often progresses silently, with many moggies showing few or no symptoms until the disease is quite advanced.

Feline heart disease comes in several forms, but the vast majority of cases seen in general practice fall under a group of conditions called cardiomyopathies. These affect the heart muscle directly and can impact how efficiently it pumps blood. Here are the most common types:

By far the most common form of heart disease in cats, HCM is characterised by thickening of the walls of the heart’s main pumping chamber (the left ventricle). This thickening reduces the heart’s ability to relax and fill properly, which in turn leads to poor circulation and potential fluid buildup. HCM is often genetic and tends to affect middle-aged to older cats, although it can occur at any age. Some breeds, like Maine Coons and Ragdolls, carry known genetic mutations linked to the disease.

DCM involves thinning and weakening of the heart walls, which compromises the heart’s pumping ability. This condition used to be more common when commercial cat food lacked adequate taurine, an essential amino acid. Since taurine supplementation became standard in the 1980s, true DCM has become rare, but it can still occur, either as a nutritional deficiency or secondary to another condition.

In RCM, the heart muscle becomes stiff or fibrotic, limiting its ability to stretch and fill with blood between beats. Unlike HCM, the walls may not appear thickened on imaging, but the functional impairment can be just as serious. It often presents with congestive signs and may be more difficult to diagnose definitively without echocardiography.

Less commonly diagnosed in cats, ARVC affects the right side of the heart, replacing healthy heart muscle with fatty or fibrous tissue. This condition can lead to irregular heart rhythms and may predispose the cat to sudden cardiac events.

Sometimes, a cat presents with cardiac disease that doesn’t fit neatly into any of the above categories. In these cases, the condition is labelled “unclassified cardiomyopathy” and managed based on clinical signs and progression.

Recognising the symptoms of heart disease in cats is tricky because many of the signs are subtle. Look out for:

●      Lethargy or reduced activity

●      Laboured or rapid breathing

●      Open-mouth breathing (especially after activity)

●      Loss of appetite

●      Weight loss or muscle wasting

●      Fainting or collapsing episodes

●      Hind limb weakness or paralysis (often from blood clots)

●      Sudden death (in severe cases)

These signs of heart disease in cats warrant immediate veterinary attention.

Studies suggest that around 10-15% of cats may be affected by some form of heart disease, but it often goes undiagnosed. Hypertrophic cardiomyopathy is the most frequently diagnosed type and can affect both pedigree and non-pedigree cats.

Common causes include:

●      Genetics: Especially in breeds like Maine Coons, Ragdolls, and British Shorthairs

●      Hyperthyroidism

●      High blood pressure (systemic hypertension)

●      Taurine deficiency (historically linked to DCM)

●      Ageing-related degenerative changes

If your vet suspects cat heart disease, they may carry out:

●      Auscultation: Listening for murmurs or abnormal heart rhythms with a stethoscope.

●      Echocardiography (heart ultrasound): The gold standard for diagnosis

●      ECG (electrocardiogram): Detects abnormal heart rhythms

●      Chest X-rays: Useful in diagnosing congestive heart disease in cats

●      Blood pressure monitoring

●      ProBNP test: A blood test that helps screen for heart muscle strain

Early detection is key, especially for kitties with a known genetic risk.

Treatment depends on the type and severity of the disease, but it often includes:

●      Medications: Such as diuretics (e.g, furosemide), beta-blockers (e.g, atenolol), ACE inhibitors, and antiplatelet drugs (e.g, clopidogrel)

●      Regular monitoring: Blood pressure checks, ultrasound scans, and ECGs

●      Managing underlying conditions, such as hyperthyroidism or high blood pressure

●      Stress reduction: Essential for cats, who are notoriously sensitive to change

Your vet will tailor treatment to your moggy’s specific needs. You can find cat health treatments and cat health supplements that can help support heart health alongside your veterinary care.

While there is no cure for most heart conditions, many cats with heart disease live happy lives with proper management. Routine vet visits, appropriate medication, and lifestyle adjustments are essential. With early intervention, you can extend your kitty’s quality of life by years.#

Cats with heart disease may benefit from:

●      Low-sodium diets

●      Taurine-rich food (especially for breeds predisposed to DCM)

●      Omega-3 fatty acids for anti-inflammatory benefits

Some medications require careful monitoring of kidney function, blood pressure, or blood clotting. Follow-up visits are essential. It is very important to never stop or alter your kitty’s medication without veterinary advice.

A heart murmur is an abnormal sound caused by turbulent blood flow. While it doesn’t always mean heart disease, it does warrant further investigation.

You can’t always prevent heart disease, but early screening, especially in high-risk breeds, can catch it sooner. Regular vet checks, good nutrition, and prompt treatment of underlying conditions all help. Check out our kitten health treatments for proactive care from a young age.

Yes. These breeds are genetically predisposed:

●      Maine Coons (linked to HCM)

●      Ragdolls

●      British Shorthairs

●      Sphynx cats

Even so, any moggy can be affected. Genetic testing is available for some conditions.

Exactly how long a cat can live with heart disease does vary. Some live only a few months after diagnosis, especially with congestive signs, while others may live several years with proper treatment and monitoring.

Heart failure occurs when the heart can no longer pump blood effectively. In congestive heart disease in cats, fluid builds up in the lungs (pulmonary oedema) or chest cavity (pleural effusion).

Signs of heart failure are more dramatic:

●      Severe difficulty breathing

●      Open-mouth breathing

●      Bluish gums or tongue (cyanosis)

●      Extreme lethargy

●      Collapse

Immediate emergency care is required if any of these clinical signs are seen.

Yes, while heart failure is serious, the condition can often be stabilised. Treatment may include oxygen therapy, injectable diuretics, and hospitalisation, followed by ongoing medication at home.

Heart disease itself isn’t usually painful, but complications like blood clots or fluid accumulation can cause pain and discomfort. Fortunately, your vet can manage these symptoms and support your cat, making them as comfortable as possible.

Whether you're caring for a kitty diagnosed with heart disease or simply being proactive, knowledge is your best tool. Heart disease in cats can be daunting, but with early detection, expert guidance, and the right support products—from first aid kits to supplements—you can help your moggy thrive.

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