Dilated Cardiomyopathy in Dogs
Definition of Dilated Cardiomyopathy
Dilated cardiomyopathy, or DCM, is a disease characterized by an enlarged heart. Dogs with DCM have abnormal heart muscle fibers which prevent the heart from contracting properly. Blood backs up, causing the heart chambers to stretch and thinning their walls. This further impairs the heart’s ability to pump and reduces the amount of circulating blood. All tissues are adversely affected by decreased delivery of oxygenated blood; the lungs and kidneys are especially vulnerable. Congestive heart failure and/or heart rhythm abnormalities often accompany DCM, especially in large dogs. What causes DCM isn’t known. A number of things have been suggested, including malnutrition, immune system problems, infection and genetics. Most dogs with DCM seem unaffected by their condition early-on. As DCM progresses, affected animals usually cough and develop frightening, painful breathing problems. In most cases, this disease ultimately is fatal.
The causes of dilated cardiomyopathy (DCM) are not known. The medical term for this is “idiopathic”. A number of different things have been suggested as possible contributors to the disorder. These include malnutrition (dietary deficiencies in taurine [a sulfur-containing essential fatty acid] and/or carnitine [a co-enzyme of fatty acid oxydation), immune-mediated abnormalities, viral infection, protozoal infection, microvascular hyperreactivity and genetic disorders involving specific myocardial (heart muscle) structural or contractile proteins. Hypothyroidism and myocarditis have also
Many dogs with dilated cardiomyopathy (DCM) seem to be unaffected by their serious heart condition, or at least they often show no outward signs of discomfort or distress. However, when DCM becomes clinical – which means that observable signs of the condition exist – affected animals usually have respiratory difficulties which we can only assume are uncomfortable at best, and extremely painful and frightening at worst.As mentioned above, many dogs with DCM do not show
Dilated cardiomyopathy (DCM) often goes undiagnosed, even for many years. Unfortunately, it frequently is only discovered when an affected dog suddenly dies for no apparent reason. Sometimes, DCM is an incidental finding during an otherwise routine physical examination, or when a veterinarian is taking chest radiographs (X-rays) for some other reason and notices an abnormally large cardiac silhouette. The attending veterinarian may hear abnormal heart or lung sounds when listening to the chest of
All but the most severely affected dogs with dilated cardiomyopathy (DCM) usually can be treated on an outpatient basis, meaning that they rarely require hospitalization. The therapeutic goals for treating DCM are to resolve the signs of any associated congestive heart failure, alleviate any build-up of fluid in the lungs, chest and/or abdomen, improve the force of heart muscle contractions, control life-threatening irregular heart rhythms, relieve the dog’s discomfort and improve the dog’s overall quality