Introduction
Deafness in dogs can be one of two kinds: conductive or sensorineural.
Conductive Deafness
If sounds cannot travel properly in the external or middle ear (i.e. sound does not conduct properly), the problem is said to be conductive. This can occur when there is an ear infection, a ruptured eardrum, blocked ear canals or fluid in the ear. Usually in these patients, hearing loss is only partial and treatment involves medical or surgical correction. If this is the case with your dog, a veterinarian may be able to resolve your pet's deafness.
Sensorineural Deafness
If the deafness is sensorineural, the inner ear is involved and deafness is usually total. Sensorineural deafness is often due to nerve abnormalities or problems with the hydrodynamics or physics of the inner ear. As pets get older, deafness is a common occurrence and sensorineural deafness may be the cause.