sudden deafness

Question
My 12 yr old corgi has had sudden hearing loss. The vet doesn't see anything and says the only thing to do is a cat scan.   I am using a vet ear cleaning solution(VET) and am going to try Atarax. Sometimes it is total deafness and at others she can hear slightly.

Answer
IF the dog is truly deaf, then this would have to be in both ears.  If a dog is deaf in only one ear, they will not indicate it to you. The first thing I would recommend is a good deep video otoscopic exam of the dog's eardrums to see if they are occluded by wax, which is extremely common, or if there is a problem in the middle ear, with the eardrums bulging. I suggest this because you stated that there is sometimes slight hearing.  If the pressures in the middle ear reduce, sound waves can get to the inner ear (the cochles) much easier.  Nerve deafness, like people get is uncommon in dogs because dogs just don't live long enough for these nerves to degenerate as they do in people.