Otoconial pathology in a strain of the waltzing guinea pig

The waltzing guinea pig is born with a clinically apparent vestibular dysfunction. In the present study otoconia in the maculae utriculi were studied with scanning electron microscopy in animals aged from newborn to six months old. Malformed otoconia, dumbbell-shaped and asymmetrically shaped otoconia occurred together with otoconia showing various degrees of morphologic degeneration. It is suggested that the otoconial pathologic condition starts prenatally and that an abnormal composition of endolymph may further contribute to the vestibular dysfunction.