Dilated cardiomyopathy is a disease of the heart muscle, which leads to dilation and enlargement of the heart's left ventricle (the heart's main pumping chamber) and consequently the heart becomes weaker and unable to pump blood effectively.
A variant of the phospholamban gene has been found to be associated with symptoms of the disease DCM in the Welsh Springer Spaniel breed, and a DNA test is now available at Laboklin. Phospholamban plays an important role in regulating the intracellular calcium concentration and therefore the cardiac contraction and relaxation. Left ventricular dilation, poor systolic function, arrhythmia and sudden cardiac death are typical symptoms seen in affected dogs. Usually, symptoms become apparent by the age of 20 months. The disease is inherited in an autosomal dominant manner with variable penetrance. Compared to other canine cardiac diseases, the dilated cardiomyopathy in the Welsh Springer Spaniel has a high penetrance, which means that dog carrying the variant are extremely likely to suffer the disease when they reach the its age of onset.