VETERINARY MEDICINE: Dilated Cardiomyopathy in Dogs (DCM).

VETERINARY MEDICINE: Dilated Cardiomyopathy in Dogs (DCM). Dilated Cardiomyopathy (DCM) is one of the most common acquired heart diseases in dogs. This disease is rarely diagnosed in cats or small-breed dogs; however, it is a common cause of heart disease in large and giant breed dogs, and usually occurs more in those that are middle- to older-aged. DCM is a condition where the heart muscle (myocardium) loses its ability contract normally and as effectively . Although DCM can affect both sides of the heart simultaneously or separately, myocardial failure of the left side is most common. Since the heart muscle cannot work as efficiently to pump blood out of the heart, blood backs up within the heart chambers and the heart enlarges in size. If pressures on the left side of the heart become significantly high as a result of increased blood volume, left-sided congestive heart failure or pulmonary edema (fluid within the lungs) can result. Although less common, myocardial failure of the right side of the heart can also occur. Similar volume overload of the right heart may result in right-sided congestive heart failure, often resulting in excessive free-fluid in the abdomen (ascites) and/or chest (pleural effusion). A familial or genetic component is believed to exist in the majority of cases. This is because of the prevalence of the disease in specific breeds such as the Doberman Pinscher, Great Dane and Boxer. The signs of DCM vary depending on the breed of dog and stage of the disease. Loss of appetite, pale gums, increased heart rate, coughing, difficulty breathing, periods of weakness, and fainting are signs commonly seen. Since blood (plasma) is being backed up into the lungs, respiratory signs are usually due to pulmonary edema and/or heart enlargement. Blood returning to the right side of the heart from the body may also back up leading to fluid accumulation in the abdomen (ascites) or in the chest cavity (pleural effusion). Weakness or collapse may be caused by abnormal heart rhythms (arrhythmias) and poor distribution of blood (depressed cardiac output). Treatment is tailored based on clinical presentation of each individual patient.