The overall goal of this study is to complete the pivotal validation of SensVita’s prototype near-field radiofrequency harness for continuous, noninvasive monitoring of dogs with myxomatous mitral valve disease, the most common heart disease in dogs. Specifically, the study aims to validate the device's measurements of resting respiratory rate and heart rate in the context of congestive heart failure, and to correlate estimated heart volume with echocardiographic indicators of disease severity.