Heart Disease in Cats

Alison Laurie-Chalmers, Senior Consultant, Crown Vets

Heart disease can have a huge impact on your cat’s overall health and has the potential to lead to heart failure if left untreated. It is important for cat owners to understand the different types of heart disease that can develop, including causes, symptoms and treatments available.

Cat heart disease can be divided into two categories; Congenital (where a heart defect is present from birth) and Acquired (where heart disease occurs as a result of damage to the heart during a cat’s life).

Congenital heart disease is usually caused by a birth defect in a valve or in the wall that separates the left and right side of the heart. These defects disrupt the flow of blood and can cause a heart murmur. This is normally detected during a kitten’s initial health checks however symptoms of congenital heart disease can sometimes go unnoticed for many years.

Acquired heart disease usually occurs as cats get older due to general wear and tear on the structures of the heart. Acquired heart disease can also result from an injury or chronic infection or as a result of other health conditions including anaemia, high blood pressure and hyperthyroidism.

The most frequent type of heart disease found in cats is cardiomyopathy, which is a disease of the heart muscle. Hypertrophic cardiomyopathy (HCM) is by far the most common cardiomyopathy. This condition causes the heart muscle walls to become far too thick, narrowing the heart chamber and spaces that the blood flows through which weakens the pumping action of the heart. HCM has been diagnosed in cats as young as 4 months and as old as 16 years. Some breeds of cats e.g. Maine Coon and Rag Dolls are more predisposed to HCM. 

Cats can also experience a dilated cardiomyopathy which can occur if their long term diet has lacked the amino acid taurine. However, most modern, balanced, complete cat foods now contain adequate amounts of taurine, so this form of heart disease is now becoming very rare.

Regular medication can hopefully help to control the symptoms of heart failure resulting from cardiomyopathies. Medications can help relax the muscle, slow down the heart rate, decrease the workload of the heart and clear congestive symptoms secondary to heart disease. Cats with enlarged heart chambers due to progressing heart disease are at risk of developing blood clots so anti-clotting medications are also prescribed. 

Although the causes of adult onset heart disease are still largely unknown, lifestyle factors, including diet and exercise, are now believed to play an important role. So do avoid obesity and give your cat a healthy diet and provide plenty of opportunities to exercise.

Due to their sedate nature and lifestyle, most cats are adept at hiding the symptoms of heart disease until the condition becomes well advanced. Some subtle early signs include; shortness of breath, increased effort in breathing, reduced appetite, a cough, lethargy and a reluctance to exercise.

Due to the lack of obvious symptoms in cats, the best way to identify heart disease early is by arranging regular health checks with your vet. These health checks play an important role in assessing your pet for any symptoms or signs on the clinical examination of heart disease. Cats with diagnosed heart disease will need to be monitored closely for any changes in their breathing and vital signs, as well as attending regular health checks with your vet practice.