Changes in the thickness and/or contractility of the muscles making up the heart are termed cardiomyopathies. The two main types of cardiomyopathies that dogs and cats can suffer from are hypertrophic cardiomyopathy and dilated cardiomyopathy.
In hypertrophic cardiomyopathy, the muscular heart walls become excessively thickened, shrinking the chambers of the heart and disrupting normal filling of the heart with blood. With dilated cardiomyopathy, the opposite occurs: The heart walls become thin and weak, making normal contractions difficult. Regardless of the type, a cardiomyopathy can lead to overt heart failure if progression occurs.
Cardiomyopathies are more prevalent in cats than they are in dogs. Middle-aged male cats seem to be affected the most. In addition, Siamese, Burmese, and Abyssinian cats appear to have a higher incidence of this disorder than do other breeds. The causes of hypertrophic cardiomyopathy in cats remain unknown; however, researchers have found a link between dilated cardiomyopathy and dietary deficiencies in the amino acid taurine.
An increased lethargy and loss of appetite might be the initial signs seen in cats with cardiomyopathies. Other more advanced clinical signs can include coughing, difficulty in breathing, and overt collapse. Vomiting can also become a factor, especially if there is secondary kidney damage caused by poor blood circulation. In addition, hind-end weakness and muscular pain due to aortic thromboembolism can be seen in these cats.
These clinical signs can help lead a veterinarian to a diagnosis of cardiomyopathy in a cat. Using a stethoscope, the veterinarian can detect rapid heart rates, abnormal rhythms, and heart murmurs as well. Radiographic X rays and ultrasound show abnormal heart shapes, abnormal heart wall thickness, and, if heart failure is present, fluid buildup within the thorax in these cats.
Electrocardiograms are useful in determining the extent of any heart enlargement and to assess the electrical conduction occurring within the heart walls. If a taurine deficiency is suspected, measuring blood levels of this amino acid can prove or disprove such suspicions.
Treatment of cardiomyopathy consists of medications designed to reduce blood pressure and to increase the efficiency of heart contractions. Drugs designed to move fluids out of the lungs might also be prescribed. In cats with advanced heart failure, oxygen therapy might be necessary. Obviously, for those cats with taurine-deficiency cardiomyopathy, taurine supplementation should also be used to normalize cardiac function.
Unfortunately, little can be done to reverse the anatomic changes to the heart seen in most cardiomyopathies. With supportive treatment, however, the quality of life of affected felines can be maintained at a good level for months, even years.
In hypertrophic cardiomyopathy, the muscular heart walls become excessively thickened, shrinking the chambers of the heart and disrupting normal filling of the heart with blood. With dilated cardiomyopathy, the opposite occurs: The heart walls become thin and weak, making normal contractions difficult. Regardless of the type, a cardiomyopathy can lead to overt heart failure if progression occurs.
Cardiomyopathies are more prevalent in cats than they are in dogs. Middle-aged male cats seem to be affected the most. In addition, Siamese, Burmese, and Abyssinian cats appear to have a higher incidence of this disorder than do other breeds. The causes of hypertrophic cardiomyopathy in cats remain unknown; however, researchers have found a link between dilated cardiomyopathy and dietary deficiencies in the amino acid taurine.
An increased lethargy and loss of appetite might be the initial signs seen in cats with cardiomyopathies. Other more advanced clinical signs can include coughing, difficulty in breathing, and overt collapse. Vomiting can also become a factor, especially if there is secondary kidney damage caused by poor blood circulation. In addition, hind-end weakness and muscular pain due to aortic thromboembolism can be seen in these cats.
These clinical signs can help lead a veterinarian to a diagnosis of cardiomyopathy in a cat. Using a stethoscope, the veterinarian can detect rapid heart rates, abnormal rhythms, and heart murmurs as well. Radiographic X rays and ultrasound show abnormal heart shapes, abnormal heart wall thickness, and, if heart failure is present, fluid buildup within the thorax in these cats.
Electrocardiograms are useful in determining the extent of any heart enlargement and to assess the electrical conduction occurring within the heart walls. If a taurine deficiency is suspected, measuring blood levels of this amino acid can prove or disprove such suspicions.
Treatment of cardiomyopathy consists of medications designed to reduce blood pressure and to increase the efficiency of heart contractions. Drugs designed to move fluids out of the lungs might also be prescribed. In cats with advanced heart failure, oxygen therapy might be necessary. Obviously, for those cats with taurine-deficiency cardiomyopathy, taurine supplementation should also be used to normalize cardiac function.
Unfortunately, little can be done to reverse the anatomic changes to the heart seen in most cardiomyopathies. With supportive treatment, however, the quality of life of affected felines can be maintained at a good level for months, even years.
Post a Comment