The albino gene can cause deafness, and i have heard about cats and dogs both that had this problem. It is also showing up in Australian Shepards when they breed two merle-gene dogs together. This can produce what they calla double-merle, and they have a lot of white from the merle/albino gene, along with the Aussie markings, and usually the white or light blue eyes. some of these dogs are also born deaf, and I think that the Aussie association has stopped them from breeding merle to merle now.
Merles have become a popular color in several breeds, including the Dachshund and the Pomeranian, as well as chihuahuas; so there are still a lot of breeders who are not aware of the dangers of breeding the merles together.
