Feline Mitral Valve Disease

Mitral valve disease is one of the most common types of heart disease to affect cats. The mitral valve is located between the left ventricle and the left atrium. It's responsible for keeping the blood flowing through the left side of the heart in a normal fashion, rather than backwards. When the mitral valve becomes worn out, the blood will begin to flow backwards and return to the left atrium.

Mitral valve disease is a progressive condition which has the potential to be fatal over time, and most cases will lead to some form of heart disease.

Development of Mitral Valve Disease

Mitral valve disease occurs when the mitral valve becomes weak and unable to redirect the flow of blood in the heart to the left ventricle. There are several factors which can be attributed to the development of mitral valve disease, including age, breed, weight and birth defects.

Most commonly, mitral valve disease develops in cats due to advanced age. As a cat begins to get older, many of the organs and muscles in the body begin slowing down and become weaker as a result of age and usage. When this happens, the heart muscle becomes less able to tolerate consistent usage. The mitral valve becomes weak and blood flow is reversed.

Genetics and breed most definitely play a role in feline mitral valve disease. While there is no understanding as to why genetics can pass down such afflictions, it is known that mitral valve disease can be more predominant in particular breeds and bloodlines.

Obesity is one of the most obvious ways that mitral valve disease can occur in cats. Cats have a relatively small frame, weighing on average only 10 pounds, and the heart is only designed to tolerate the load of so much weight. When the normal weight level of a cat is exceeded, it forces the muscles of the heart to work harder at their job, and they tend to weaken over time.

Birth defects can't be avoided, but there is the possibility that a cat can be born with a loose or weak mitral valve. This type of mitral valve disease will present much earlier in life.

Signs of Mitral Valve Disease

When symptoms of mitral valve disease are noticed in cats, the condition is usually too far progressed to provide a sufficient treatment. However, any of the following signs should prompt a visit with a veterinarian:

Diagnosis and Treatment of Mitral Valve Disease

In order to diagnose a case of mitral valve disease in a cat, the following tests will need to be performed:

  • A chest x-ray
  • An electrocardiogram
  • An echocardiogram

A chest x-ray will show any swelling of the sac around the heart, which can indicate the build up of fluid or excessive blood. An electrocardiogram will measure the electrical activity of the heart and will identify any abnormalities in the function of the heart. Perhaps the most definitive method of diagnosis is the echocardiogram, or sonogram. The echocardiogram will get a much closer look at exactly how the heart is functioning and will make the ill-functioning mitral valve visible.

Diuretics and nitroglycerin can be used as a means of removing extra fluid from the body and dilating the blood vessels to permit more adequate blood flow. Other methods, such as vasodilators and enzyme blockers, can also be effective at allowing the vessels and arteries to expand, to allow more blood flow throughout the body. Unfortunately, there is no way to surgically correct a weak mitral valve.