Expert: Dr. Louis N. Gotthelf - 12/8/2011

Question
I purchased a Bernese Mountain Dog puppy at 8 weeks of age and had it flown to me. By 11 weeks of age, I noticed she could not hear.  She would sleep and not wake up to my voice except by me hitting the floor.  She had a very loud high pitched bark also.  I contacted the breeder and she told me that the puppy could hear fine when she was in her care. She would respond to noise.  
My question is at what age can deafness develop if it is an issue the puppy was born with, since she was never exposed to loud noices, antibiotics, ear cleaning solutions, or any other chemical?  
Also, is deafness genetic or congenital? I have read a ton on the internet about this, but one thing says it's not genetic that it is congenital and the other thing says that deafness is genetic.

Answer
I am unaware of any genetic deafness in Bernese Mountain Dogs. We usually see genetic hearing problems in white colored dogs because part of the cells responsible for hearing contain melanin, the black pigment.  A congenital defect just happens...it has nothing to do with genetics.  It could be, for example, that the ear canals do not open normally.  Without hearing tests, it is hard to tell what the dog may hear or not hear.  They do these tests at Auburn University.