Pompe disease is a generally fatal, recessively inherited disease of Swedish and Finnish Lapphunds and Lapponian herders. It is a type of glycogen storage disease caused by a deficiency of functional acid alpha-glucosidase, which leads to the accumulation of glycogen within cells. In particular this affects the brain, liver and muscle cells, including the heart muscle and smooth muscle of the oesophagus (food pipe). Signs of Pompe disease are generally first seen at around 6 - 7 months of age, and most dogs do not survive beyond the age of two years. Signs include poor growth and progressive muscle weakness, exercise intolerance, regurgitation due to megaoesophagus (dilated oesophagus) and heart disease. Cardiomyopathy (heart muscle disease) leads to panting, exercise intolerance and weakness, possible fainting and eventually the dog’s severity of illness will require euthanasia. There is currently no treatment for Pompe disease, although the genetic mutation that causes it has been determined, and a DNA test is available. This allows for screening of breeding animals so that no affected animals are produced.