Congenital Deafness
History. An owner brings you an 8-week-old, almost completely white, male Dalmatian and reports that the pup does not appear to hear anything.
Clinical Examination. Your physical examination reveals a seemingly normal, healthy Dalmatian pup except for his apparent deafness.
He does not seem to respond to voice commands or loud noises. Veslibular and all other neurological reflexes are within normal limits. A brainstem auditory-evoked response is flat, which suggests that the brain has not received any signal from the cochlea.Comment. Congenital deafness is fairly common in dogs and other animals with white coat color. It is usually caused by the partial or complete absence of the cochlea and occasionally by the absence of other neural elements in the auditory pathway. This is known as “nerve deafness” and is usually present at birth (congenital). Why it is linked to white coat coloration is unknown, but the pattern suggests that this is a genetically determined failure, usually bilateral, of the cochlea to develop. This dog can have a relatively normal life as long as the owners are attentive.