Heart conditions such as dilated cardiomyopathy, where the heart becomes weakened and enlarged, and sick sinus syndrome, which is a type of abnormal heart beating which causes low blood pressure, have been identified in the breed. Phosphofructokinase deficiency is a condition caused by a recessive gene in the breed which prevents the metabolism of glucose into energy, causing the dog to have extremely low energy and be unable to exercise. The gene which causes this appears in around 10 percent of the population, but DNA testing can prevent two carrier dogs from breeding and thus creating puppies with this condition.