Professor Brendan Corcoran is Professor of Veterinary Cardiopulmonary Medicine and Director of International Affairs in the University of Edinburgh's Royal (Dick) School of Veterinary Studies. Canine heart valves open and close millions of times during a dog’s lifetime. These valves are essential for healthy blood circulation, but of all the valves the mitral valve is most prone to degenerate and eventually fail. This causes heart failure. Approximately 15% of the UK’s dog population is affected by heart disease. This lecture will unravel the mysteries of mitral valve disease and the possible solutions to this problem. This lecture is part of the Medical Detectives, a series of public lectures that show how keen detective work is still essential for 21st century doctors: http://www.ed.ac.uk/news/events/medical-detectives/ Recorded on Thursday 28 October 2010 in the Anatomy Lecture Theatre at the University of Edinburgh.