Heart Disease in my Cat – Cardiomyopathy

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Heart Disease in my Cat – Cardiomyopathy

Heart Disease in Cats - Cardiomyopathy

Felines are masters of disguise when it comes to discomfort and disease, nowhere is this truer than when it comes to cardiomyopathy in cats.

Cardiomyopathy refers to diseases of the heart muscle and can lead to heart failure. Feline cardiomyopathies are the most common cause of heart disease in domestic cats.

Our beloved ambassador ‘Milla’ who is a Scottish fold was diagnosed with congestive heart failure at age two, this has given us a personal insight into heart disease in cats and allowed us to become fully informed on the subject.

There are four primary types of feline cardiomyopathy outlined below and each is described based on the effect on the structure and function of the cardiac muscle.

Most common heart diseases in cats:

  • Hypertrophic Cardiomyopathy (HCM)- HCM is the most prevalent feline cardiac disease, a primary disorder of the heart muscle characterised by the thickening of the left ventricle.The cat’s heart is unable to relax normally when filling with blood and over time can lead to elevated pressures and ultimately congestive heart failure in cats.
  • Dilated Cardiomyopathy (DCM)- DCM is a heart disease which affects the cat’s ventricular muscle and is characterised by dilated, or enlarged heart chambers, reducing the contraction ability.
  • Restrictive Cardiomyopathy (RCM)- RCM is a heart disease in cats caused by excessive build-up of scar tissue on the inner lining of the ventricle. Thus, preventing the ventricle from adequately relaxing, filling, and emptying with each heartbeat.
  • Intermediate Cardiomyopathy (ICM)- ICM is somewhat more difficult to define and has features of both dilated and hypertrophic cardiomyopathy present.

What’s going on in Cardiomyopathy?

Heart disease in cats is brought about by a structural abnormality in one or more of the four chambers of the heart.

Milla suffered with the most common heart problem in cats Hypertrophic Cardiomyopathy (HCM) which obstructed blood flow in her heart resulting in poor heart function.

However, the alteration in a cat’s heart function is dependent on the type of cardiomyopathy:

  •   With HCM & RCM- This heart disease in cats is characterised by a ‘thickening’ which stops the heart muscle from relaxing properly between contractions. The relaxation between each cardiac contraction phase is known as ‘diastole’ and if this is interfered with the heart cannot fill blood properly. This is a specific form of heart failure in cats known as ‘diastolic heart failure’.
  • With DM- DM is a heart disease in cats which obstructs the heart muscle from contracting, compromising the ability of the heart to pump blood. This can lead to heart failure in cats and is commonly known as ‘systolic heart failure’.

Signs of Heart Disease in Cats

Given their wild ancestry, cats are loath to show weakness and in the initial phase of heart disease may show no signs at all. Some cats with cardiomyopathy show no signs of clinical disease while it can be rapid in other felines.

‘Milla’ began to become lethargic and weak and had a sudden paralysis of her hind quarters which are clear signs of heart disease.

Heart disease in cats can be detectable through a clinical visit to your vet, cat pet insurance can cover visits.

Symptoms of heart disease in cats include:

  • Heart Murmur- 
    The presence of a feline heart murmur can be detected by your vet using a stethoscope, it is an obstruction of blood flow through the heart, commonly caused by a thickened muscle wall in the heart.
  • Gallop Rhythm- When listening to the heart with a stethoscope your vet can pick up two sounds linked to each cycle of a cat’s heart contractions. If a cat has heart disease a third audible sound is detected and referred to as the ‘gallop sound’ or ‘gallop rhythm’.
  • Heart Rate- Heart disease in cats can see significant increases or decreases in heart rate outside the normal range. In some cases, there may be heart beats without any pulse detected which is commonly known as ‘pulse deficit’.
  • Cardiac Rhythm Disturbances- Also known as ‘Sinus Arrythmia’ in cats this can cause abnormal variation in the cycling of impulses which regulate the heart’s beating action. This results in irregular rhythm and a cat’s heart may beat - too slow, fast, skip beats - leading to cat heart attack


Presently the underlying causes of cardiomyopathy in cats are rarely treated, however if secondary conditions develop such as hypertension or hyperthyroidism treatment for these conditions may help cardiac function.

Treatments for heart disease in cats can be covered by pet insurance, companies such as Petsbest Insurance review help cover costs.


Through our experience with ‘Milla’ we learned a great deal about how pet insurance works and wanted to pass on this valuable information to other pet lovers, in effect this is how was born.

Various drug treatments are available to help and improve heart disease in cats and include some of the following:

  • Beta-blockers - Beta-blockers cause your heart to beat more slowly and with less force, slowing down the heart rate and reducing the oxygen demand on the heart. Examples of beta blockers for heart disease in cats include Atenolol and Propranolol.
  • ACE-inhibitors- This medication helps relax the blood vessels in cats, enabling the heart to pump blood with less effort leading to lower blood pressure and decreased oxygen demand from the heart. They work also in helping to block the hormone system stimulated in cats with heart disease known as renin-angiotensin-aldosterone system (RAAS). Their use is helpful in the management of heart failure in cats and in the early stages of heart disease in cats.
  • Diltiazem - Also known as a calcium channel blocker diltiazem works by relaxing the smooth muscle in the walls of the arteries, resulting in them opening and allowing blood to flow more easily. It also reduces a cat’s heart rate and the strength of heart contractions lowering the oxygen demands of the heart and helping the heart muscle to relax.

Heart Failure – Congestive Heart Failure

Milla was diagnosed with congestive heart failure in 2015 and only given 3-6 months to live, an adorable creature with mesmerising orange eyes and the most infectious personality.

Following this diagnosis, we informed ourselves of the subject and in working with the best medical professionals and pet insurance representatives, Milla got the best care available and is now back to full health.

In fact, you can now follow ‘Milla’s’ adventures on her instagram page. Through Milla’s illness we found out heart function is significantly impaired by cardiomyopathy; it can lead to heart failure resulting from the obstruction to cardiac inflow and a decrease in blood flow from the heart.

Congestive heart failure in cats can be divided into four functional classifications: pressure overload, volume overload, impedance to cardiac inflow and systolic myocardial failure.
Telltale signs of heart disease in cats can develop without warning and felines can deteriorate very rapidly with heart disease.

The most common signs of heart failure in cats is difficulty in breathing, loss of appetite, or a reluctance to exercise although this can be difficult to spot in cats. A decreased volume of blood pumped out of the heart can cause a cat’s body temperature to lower and the paws and ears may feel cold.

It is unusual for a cat to cough this is more prevalent in dogs with heart disease, on occasion you may notice the mucous membranes of the mouth, eyes and even skin showing signs of cyanosis.

If your cat is showing any of the above signs, it is imperative you bring it to your local vet for diagnosis.