Histopathology of the temporal bones of deaf dogs

Histopathological studies were done in 22 deaf dogs consisting of 10 Dalmatians, 5 English setters, 2 Great Danes, 2 foxhounds, 1 shepherd, 1 bulldog and 1 Australian sheep dog. Hypoplasia or aplasia of the sensory cells of the organ of Corti, stria vascularis and macula sacculi (pars inferior) was noted in all deaf dogs examined, indicating the pathology of inner ear malformation in these dogs to be of Scheibe's type. A solidified and calcified tectorial membrane was noted in 19 out of the 22 deaf dogs. A calcified sclerosis of the tectorial membrane is thought to be a characteristic finding of genetically inherited anomaly of the inner ear in deaf dogs. Distortion of the tectorial membrane, absence of the sensory cells in the organ of Corti, agenesis of the stria vascularis and abnormalities of the saccule described Scheibe's dysgenesis of the pars inferior as the pathological correlate for deafness in these dogs as assessed functionally.