Diseased Canine Valve (IMAGE) Tufts University Caption Cross-section of a severely diseased heart valve in a dog with myxomatous mitral valve disease and congestive heart failure. Credit Courtesy of Tufts University Usage Restrictions May use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.