Are All White Dogs Deaf?
So what, if anything, does a white coat have to do with hearing loss? The ability to hear is made possible by a special layer of cells within the inner ear. This specialized layer of cells, and the cells that determine a dog’s hair color, come from the same stem cell source. Without this stem cell, the dog’s body won’t be able to make this specialized layer of hearing cells and will likely be white in coloration.
Dogs that carry the piebald gene are often affected by deafness. Piebaldism results from the absence of melanocytes, the cells that create the pigment melanin. These melanocytes are the part of a dog’s DNA that determines coloration, such as brown or black hair, or blue or brown eyes (blue eyes are not a true eye color, but rather result from the lack of color-producing pigment within the iris). When a dog is born without melanocytes, a predominantly white coat (and often blue eyes) is the result. Breeds commonly affected by the piebald gene include Bull Terriers, Boxers, English Setters and Dalmatians.
Congenital deafness is also linked to the merle gene, which causes a dog to have a merle (or dapple) coat and blue eyes. Breeds commonly affected by the merle gene include Old English Sheepdogs, Dachshunds, Welsh Corgis, and Border Collies.
What is Deafness in Dogs?
Deafness is defined as a loss of hearing caused by a delivery interruption of sound to the brain. When sound waves reach the eardrum, it vibrates like a big gong, causing the middle ear bones (or “ossicles”) to vibrate as well. These vibrations reach the fluid-filled, spiral-shaped cochlea of the inner ear, creating waves.
All this commotion causes a pressure change and forces the cochlea’s hair cells to move. These hair cells are connected to the auditory (hearing) nerves, which sparks a nerve impulse down the auditory pathway that connects to the brain. Deafness is a result of this process failing at some point.
Why You Should Get Your Dog’s Hearing Tested
For dog breeders, testing the breeding stock for deafness before they’re bred allows a better understanding of the type of genes that the sire or dam may pass on to his/her offspring. While testing helps avoid producing puppies that are hearing-impaired, the BAER test does not completely ensure the hearing of the resulting puppies.
For dog owners, knowing that their pets are partially or totally deaf will make it easier for them to address their deaf dog’s needs, such as developing appropriate communication and training techniques (use of hand signals or exaggerated body language). Necessary precautions can also be made to protect deaf dogs from potential dangers, such as vehicles and predators. The awareness and understanding of pet parents regarding their dog’s condition are very important so measures can be taken to ensure the dog will live a happy and healthy life.