Grade 4 endocardiosis

Grade 4 endocardiosis in the parietal cusp of a mixed breed dog’s mitral valve. Endocardiosis is a degenerative disease, usually found in elderly animals, characterized by myxoid degeneration of the free border of a cusp with formation of small nodules which deform the free surface of the cusp, eventually compromising valvular function. Endocardiosis is classified in four grades of ascending severity, with grade 4 lesions severely distorting the cusps and resulting in valve insufficiency.