Mary Allen
Deafness in cats can have various causes, such as acute or chronic ear diseases. White cats and blue-eyed cats are significantly more likely to be deaf than cats of other colors. Why is that?
The fact that blue-eyed and white cats are often deaf is probably due to genetics. The specific gene responsible for light coat and eye color may also be responsible for deafness.
Defect on the White Gene Responsible for Deafness?
So a genetic defect is probably the culprit. The white pigment gene is inherited in an autosomal dominant manner and “masks” actual coat color; it is found in several breeds of cats, albeit often only partially as a piebald. This hereditary factor is more prevalent in some breeds, for example, Maine Coon, Turkish Angora, British Shorthair, Persian Cat, Norwegian Forest Cat, or Devon Rex. As a result, they are more susceptible to congenital deafness than cat breeds that have a lower genetic factor.
The exact mode of inheritance for deafness in blue-eyed and white cats is not well understood. A gene is thought to be responsible for both deafness and color. However, the exact pattern of inheritance is difficult to decipher and so it is not known for sure which specific conditions must be met for deafness to actually appear.
Gene Defect Causes Missing Organ of Corti
How does the genetic defect lead to deafness? White cats that can’t hear often lack an organ in their inner ear: the organ of Corti. The organ of Corti is responsible for transmitting the vibrations in the cat‘s ear – if it is missing, the sounds don’t get where they should so that the velvet paw can hear them. Cats that lack the organ of Corti must not be bred from, as this would otherwise be a form of torture.