Testing was performed at LSU, specialty and all-breed dog shows, and sponsored hearing clinics. No significant sex differences in deafness prevalence were seen. Insufficient numbers of blue-eyed dogs were seen in other breeds for analysis. Similar associations with parental hearing were seen for ECS, but parent hearing status data were insufficient for analysis in the other breeds. Deafness may affect one or both ears, but partial hearing loss in an ear does not appear to occur in this disorder.
Unilateral deafness is thought to reflect incomplete expression of the defect.
This deafness is thought to have a hereditary component, since prevalence is higher in the offspring of unilaterally deaf dogs than of bilaterally hearing dogs. Current findings indicate that deafness in these dogs actually occurs approximately 3 weeks after birth, when cochlear hair cells die secondary to degeneration of the stria vascularis in the cochlear duct. In an effort to better understand the relationship between congenital sensorineural deafness and phenotypic traits we have collected data on deafness prevalence, pigmentation markers, and gender from dogs of breeds with a high prevalence of deafness while documenting the hearing status for owners and breeders. Statistical correlations between hearing status, gender, and pigmentation markers were then evaluated. Numbers of tested dogs from other affected breeds were of insufficient size for analysis.