Cardiomegaly is a broad term used to describe any condition that causes an enlarged heart. A cat with an enlarged heart is at risk for developing a number of health problems, and as a pet parent it is useful to be aware of the different types of cardiomegaly, the dangers, and what you can do to prevent and treat the condition. Read on to learn what you need to know.
2 Types of Cardiomegaly
There are two types of cardiomegaly:
- Hypertrophic: The most common type of cardiomegaly, it is characterized by a thickening of the heart muscle tissue in response to a heavy workload. This type of cardiomegaly causes poor heart function and obstruction of blood flow. This can result in a buildup of fluid pressure in the lungs, and in some cases, the development of blood clots in the heart. Heart failure is common, as is paralysis, if blood clots are present.
- Dilative: Refers to a dilation, or enlargement, of the heart muscle tissue. Although relatively rare in cats, dilated cardiomyopathy — or DCM — is an example of this type of cardiomegaly. With DCM, the heart’s walls become flimsy and weak as the muscular tissue dilates, making it difficult for blood to flow forward from the heart. This often results in heart failure.
3 Dangers of an Enlarged Heart
Cats with cardiomegaly are at risk for developing a number of conditions. These are the 3 most common dangers of an enlarged heart in cats.
- Congestive heart failure: Occurs when the cat’s heart is not able to adequately distribute blood throughout the body. When this happens, other body systems must take on some of the work, and end up becoming easily overwhelmed, leading to a buildup of fluids anywhere in the body, but most often in the lungs. Fluid in the lungs causes congestion and makes it difficult for oxygen to enter the bloodstream. Shortness of breath and lethargy are the usual symptoms of this condition.
- Thromboembolic disease: An enlarged heart results in abnormal blood flow, and this can increase the risk of developing a blood clot — or a thrombus — within the heart. It is possible for this clot to travel down the aorta artery and become lodged at its base, which is known as the saddle. The saddle delivers blood to the cat’s hind legs, and if there is a clot, it becomes an obstruction that cuts off the blood supply. This extremely painful condition can affect one or both of the cat’s hind legs and results in paralysis. It can also cause circulatory shock and/or heart failure, which can be fatal.
- Hypertension: Hypertension, or high blood pressure, is often a cause of cardiomegaly. Even when it is not the cause, cats with an enlarged heart are at risk for developing it. High blood pressure is when the blood moving through the body is being pushed too hard against the veins. For cats, this can result in a number of complications, including nosebleeds, hemorrhaging within the eye, retinal detachment, and sudden blindness.
Prevention and Treatment of an Enlarged Heart in Cats
Many cases of cardiomegaly are congenital, meaning that the enlarged heart is caused by structural problems that have been inherited and/or present since birth. Cardiomegaly can also be caused by certain health conditions, including hypertension, hyperthyroidism, kidney failure, and in the case of dilated cardiomyopathy, a deficiency of the essential amino acid taurine. The best way to prevent cardiomegaly is to visit your vet for regular check-ups. Your veterinarian may be able to identify an enlarged heart before it causes serious health complications.
The treatment for an enlarged heart will depend on whether or not an underlying cause has been identified. If the cause of your cat’s enlarged heart is known, then that cause will be treated and your cat’s condition will likely improve, or be completely reversed.
If the cause is not known (i.e., idiopathic), treatment will vary depending on your cat’s specific condition. Medications, including diuretics, beta-blockers, calcium channel-blockers, and ACE inhibitors, can all improve heart function. Aspirin may be used to reduce the risk of developing blood clots, and drugs that lower blood pressure may be used in cases of hypertension.
Surgery may be appropriate for some cats with certain congenital heart defects.
More on Heart Disease
How to Treat Heart Disease in Pets
Nutrition for Dogs and Cats With Heart Disease
Cat Heart Murmur Treatment Options
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.