Test Overview:

Cardiomyopathy is fairly common in the dog, with certain breeds showing a distinct disposition to develop the disease. It is characterised by dilation of the heart and by weakened, thin heart muscle walls (so that there is less ability to pump blood). Various breeds are suspected to have genetic tendencies towards the development of this condition, although other factors are also involved in some breeds. Cardiomyopathy results in the heart muscle becoming dilated and thin, such that it is unable to act as an efficient pump. In addition - due to the amount of stretching of the heart wall - severe arrhythmias (or irregular, often very rapid heart rhythms) occur commonly. Some dogs can die suddenly of arrhythmia; others show weakness, lethargy, syncope (fainting) and panting at rest. Diagnosis is via echocardiography (heart ultrasound) and there are various medications that are used to help the heart contract more forcefully and to control arrhythmia. Clinical signs of cardiomyopathy are commonly seen around the ages of 3 – 6 years of age. Signs of heart failure or arrhythmia are more common in males than females, however females are not less likely to develop cardiomyopathy, they just do not develop clinical signs as often as males. This is sometimes called “occult” cardiomyopathy. Occult cardiomyopathy can result in sudden death, due to a sudden onset of a fatal arrhythmia. Diagnosis is via echocardiography (heart ultrasound) and there are various medications that are used to help the heart contract more forcefully and to control arrhythmia. Generally most dogs are treated as outpatients, with a low salt diet and medications; however the prognosis is reasonably poor. The condition cannot be cured, and survival times after diagnosis are usually within weeks to months. Research is being conducted in many breeds, not only to look at the genetics of cardiomyopathy, but also the pathophysiology associated with the disease in each breed, and this has led to a number of different treatment recommendations that are specific to one or several individual breeds. Examples are supplementation with L-carnitine, taurine or co-enzyme Q-10. Some of these have led to quite significant improvement in cardiac function. There is no cure for cardiomyopathy, and medication is used to control signs and improve quality of life for as long as possible. One of the most important aspects of treatment is the control of arrhythmias, and this should be done regardless of whether there are obvious signs of heart failure or not, as arrhythmia can cause sudden death at any time. Certain breeds may have associated specific nutritional recommendations, which may also help slow down the progression of this disease. Unfortunately most dogs will succumb within a year of diagnosis.