title: Histopathological morphometric study of cochleosaccular dysplasia in Dalmatian dogs.
abstract: OBJECTIVE
  To analyze temporal bones of deaf Dalmatian dogs from 5 days after birth to adulthood to better understand the pathogenesis of cochleosaccular dysplasia.
  
  
  METHODS
  This is an experimental animal histopathological temporal bone study that included two groups of temporal bones. Group I consisted of 41 temporal bones from deaf Dalmatian dogs and group II of 25 temporal bones from 15 "normal" aged-matched, hearing Black Labradors. Morphometric analysis included: stria vascularis and spiral ligament area measurements, and cell counts of spiral ganglion, Scarpa's ganglion, and hair cells of saccular macula.
  
  
  RESULTS
  The following findings were significantly less in deaf Dalmatian group compared to hearing Labradors: (1) cellular area of the stria vascularis in all cochlear turns; (2) cellular area of spiral ligament in the inferior part of the basal turn; (3) cellular density of spiral ganglion cells within segments III and IV; (4) number of Scarpa's ganglion cells; and (5) density of saccular hair cells types I and II. A borderline negative correlation was found between average density of spiral ganglion cells of segments III and IV and age in group I. Young deaf animals showed some cochlear hair cells, however in adult dogs all hair cells were replaced by supporting cells.
  
  
  CONCLUSIONS
  General pattern of cochleosaccular dysplasia is variable, even when only one etiology, the genetic one, is involved. The gradual degeneration of inner ear elements in the cochleosaccular degeneration might indicate that early intervention might be crucial to stop the progression of cochleosaccular dysplasia.
authors.affiliation: Brasilia University Medical School - Capes, Fulbright Scholarship, Brasilia, Brazil. andremarjy@uol.com.br
authors.forename: Andre L L
authors.initials: AL
authors.lastname: Sampaio
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Paine
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Schachern
authors.forename: Carolyn
authors.initials: C
authors.lastname: Sutherland
authors.forename: Sebahattin
authors.initials: S
authors.lastname: Cureoglu
authors.forename: Carlos A C P
authors.initials: CA
authors.lastname: Olivieira
authors.forename: Michael M
authors.initials: MM
authors.lastname: Paparella
mesh_terms: D000818:Animals; D003051:Cochlea / Q000473:pathology*; D003638:Deafness / Q000151:congenital*; D004285:Dogs; D006199:Hair Cells, Auditory, Inner / Q000473:pathology; D009925:Organ of Corti / Q000473:pathology; D012444:Saccule and Utricle / Q000473:pathology; D013136:Spiral Ganglion / Q000473:pathology; D013316:Stria Vascularis / Q000473:pathology; D013701:Temporal Bone / Q000473:pathology*