On the Topic of Dilated Cardiomyopathy in German Shepherds

Dilated Cardiomyopathy in German Shepherds

Cardiomyopathy is a group of diseases that affect the myocardium, or heart muscle. Dilated cardiomyopathy is a disease where the chambers of the heart are dilated, or enlarged, due to a weakening of the heart muscle. What happens is defective transport of calcium ions within the heart muscle reduces the cell’s ability to contract. When this occurs, the heart muscle becomes thin and flabby. The thinning worsens, often unnoticed and without outside symptoms, over several months and the heart chambers become dilated. Thus the heart cannot function properly and its timing becomes off. The disease usually affects the heart’s main pumping chamber, the left ventricle. When the left ventricle becomes dilated or enlarged it cannot pump blood to the body with as much force as a healthy heart. At this time the dogs affected begin to have visible trouble. The dog falls into full congestive heart failure and then dies.

Rarely, dilated cardiomyopathy can be less severe: asymptomatic and non-life-threatening. However, most cases of this disease cause heart failure. Dilated cardiomyopathy has also been known to cause irregular heart beats, blood clots, and sudden death. The symptoms of this disease are often sudden and severe. They appear as if the dog had only gotten ill in the last few days, when in reality the dog has been living with the disease for several months. Common symptoms include difficulty breathing (dyspnoea), coughing, feinting, exercise intolerance, and a swollen abdomen. Coughing is especially prevalent during the night time. German Shepherds affected tend to have a reduced appetite and weight loss. Another symptom that may occur is arrhythmias, which causes abnormal heart rhythms. It worsens heart failure and precipitates collapse or sudden death.

More than 90% of all cases of canine dilated cardiomyopathy occur in only eight specific breeds of dog and the disease is the most common cause of heart failure in these breeds. The breeds are the Doberman Pinscher, Boxers, Great Danes, Irish Wolfhounds, Saint Bernards, Cocker Spaniels, Golden Retrievers and German Shepherds. Most likely, the disease has a genetic origin, although a mode of inheritance has yet to be documented. If a German Shepherd with this disease were to be bred, it is possible that the disease could be passed on to the offspring, although there is no proof of this occurrence. In most cases, the cause of the disease is unknown. Hypothyroidismhas has been associated with this disease and in some dogs an inflammation of the heart muscle, known as myocarditis, may precede dilated cardiomyopathy. In other dogs dilated cardiomyopathy may be related to a taurine and/or carnitine deficiency. Some other causes of the disease can include metabolic disorders, immunologic abnormalities, infectious diseases, and it may be drug or toxin-induced. The dogs most often affected by this disease are middle aged (4-6½ years) and male.

A diagnosis for this disease can be made using several different techniques. Some techniques can include a diagnosis can be based on ECG changes showing cardiac arrhythmias. And/or a chest X-ray may be taken, showing enlarged heart chambers. Also, an echocardiogram (ultrasound) may be taken, showing the characteristic pattern of a failing heart muscle. Moving echocardiography is the best diagnostic tool to diagnose dilated cardiomyopathy. This is because an ultrasound can clearly show the dilation of the heart chambers as well as other signs of the disease.

There is no treatment that can cure dilated cardiomyopathy. However, certain treatments can increase the dog’s quality of life. If the dog receives exceptional medial control, treatment can also prolong the German shepherd’s life for up to a year or more. Treatment can include adding taurine and/or carnitine to the dog’s diet to try and combat the taurin or carnitine deficiency that may have caused the disease. Treatment is also directed at improving the strength of the heart muscle as well as controlling arrhythmias and preventing the build up of fluid in the lungs and abdomen. Nitroglycerin can help improve the heart muscle by decreasing the amount of blood returning to the heart. This allows some of the blood to pool in the veins and takes some of the work load off the heart. Another drug, called digitalis helps improve heart function in several ways; slowing the heart rate and strengthening each contraction of the heart are two main functions of the drug. Despite strict treatment and constant care the dog will usually die suddenly and often without warning. Death is usually a result of sudden cardiac arrhythmia and some German shepherds will die without any noticeable preceding signs.

Canine dilated cardiomyopathy is a serious disease in German Shepherds although, thankfully, not a very common one. A German Shepherd is much more likely to acquire hip dysplasia than this disease. If a German Shepherd does have dilated cardiomyopathy, the best that one can do for it is to give it all the care and treatment they can to try and improve the dog’s quality of life as much as much as possible before the dog passes on.