AffectedAnimals:
The dogs most frequently diagnosed with DCM are large and giant purebred dogs, including Scottish deerhounds, Doberman pinschers, boxers, Saint Bernards, Afghan hounds, Newfoundlands, and old English sheepdogs. Recently, both English and American cocker spaniels have been diagnosed more frequently with DCM than other small breed dogs. Most dogs with DCM are older, as the prevalence of DCM increases with age. Male dogs are affected more commonly than female dogs for most breeds.

Overview:
The term cardiomyopathy literally means "sick heart muscle." Dilated cardiomyopathy, or DCM, occurs when the heart muscle is thin, weak, and does not contract properly. DCM most commonly affects large or giant purebred dogs, but it also can be seen in smaller breeds such as cocker spaniels, and in mixed breed dogs. The condition can lead to congestive heart failure, in which fluid accumulates in the lungs, the chest or abdominal cavities, or under the skin. Because of reduced blood flow to the rest of the body, DCM also can result in weakness, fainting, and exercise intolerance. Abnormal heart rhythms, or arrhythmias, frequently accompany DCM, and can complicate the treatment of dogs with this disease.

In rare cases, supplementation with substances such as l-carnitine or taurine may dramatically reduce signs in individual patients, but for most dogs, the main goals of treatment are to lessen signs due to congestive heart failure and to attempt to improve the heart's ability to pump blood. The long-term outlook for dogs with DCM is usually quite poor, and most dogs with DCM eventually die from the disease. Despite the poor long-term outlook, however, many dogs with DCM can benefit from medical treatment that helps control symptoms.