Mitral Valve Disease in Dogs

Mitral valve disease is the leading cause of heart failure in dogs. Although the condition appears to occur more predominantly in smaller breeds of dogs, all dogs are susceptible to weakening of the mitral valve as they age. Because of the high rate of occurrence and the severity of this condition in dogs, it is important for all dog owners to be aware of the signs and to know when to seek to medical attention.

The Mitral Valve

The heart works as a pump and is an integral part of sustaining life. The left and right atrium are the designated sides of the heart, and they play an important role in the efficiency of the heart muscle. The right atrium of the heart receives blood from the body and holds it briefly before pumping it through the right ventricle and eventually into the lungs. The blood is then pumped back from the lungs into the left atrium of the heart, where it is dispersed to the left ventricle.

Between the left atrium and the left ventricle lies the mitral valve. The purpose of heart valves is to prevent backflow of the heart chambers. Because the left ventricle receives the greatest amount of pressure in the heart, the mitral valve sometimes becomes weakened and shrinks, essentially failing to open and close properly. The tremendous pressure created by the left ventricle and the weakened state of the mitral valve causes blood to be forced back into the left atrium, rather than throughout the body. This is when the onset of mitral valve disease occurs.

Signs and Symptoms of Mitral Valve Disease

Mitral valve disease is one of the most serious heart ailments that can afflict a dog. For this reason, it is imperative that dog owners be able to recognize its signs so that treatment can be sought. Here are some of the most common symptoms:

  • Heart murmur
  • High blood pressure
  • Inflammation of the lungs and lung tissues
  • Persistent, congestive-sounding cough

The above listed symptoms are usually mild in nature and are noticed at the very initial onset of mitral valve disease. As the condition progresses, however, the dog will become very weak, lack the stamina to walk, and may even faint or collapse as a result.

Making a Diagnosis of Mitral Valve Problems

When mitral valve disease is suspected, there are three diagnostic test measures that have proven very effective in detecting this condition. The first test to be done is likely a chest x-ray. This will allow visualization of both the heart and lung fields to determine if there is any inflammation. The second is an electrocardiogram, which shows electrical activity of the heart; the third is ultrasound examination of the heart, which will show very clearly the current condition of the mitral valve.

Treatment for Mitral Valve Disease

Once the condition is developed, it cannot be stopped or reversed. However, there are some medication options available that have been known to increase the life that a dog has left. They include:

  • Diuretics – to remove fluid buildup.
  • Vasodilators – to dilate the blood vessels and allow for better flow.
  • Enzyme Blockers – to help strengthen the heart muscle and coordinate muscle contractions.