Here's a quote from the Boston Terrier link I posted earlier..."First Part of Deafness Study
This post will attempt to define deafness in dogs as has been discussed on this list. Unless otherwise stated, all references and quotations will be from several published studies by George M. Strain, Professor of Neuroscience, School of Veterinary Medicine, Louisiana State University. Dr. Strain is deemed the leading authority on the subject of deafness in dogs and cats.
Of the eight known classifications of deafness, only three are common in dogs: inherited congenital sensorineural, acquired later-onset sensorineural, and acquired later-onset conductive. It is the inherited congenital sensorineural deafness that we have been discussing on this list.
To quote Dr. Strain: "Inherited congenital sensorineural deafness is usually, but not always, associated with pigmentation genes responsible for white in the coat." This is usually associated with pigmentation patterns-- such as our BTs' white blaze, collar, and chest-- "where increasing amounts of white in the hair coat increases the likelihood of deafness." The two pigmentation genes most often associated with deafness are the merle and the piebald. It is, specifically, the piebald gene that we are concerned with in Boston Terriers. When these piebald genes (responsible for the white) are overly expressed, the other pigment genes normally in the blood supply are repressed. Now this "tainted" blood supply to the cochlea, causes degeneration of the nerve cells, which causes irreversible deafness." |