i dont know in animals but in humans it is a sign of a bigger disease. and there are, like in most conditions, mild to extreme cases. if it is that bad in animals as well, i dont understand why you would want to BREED a disease, as like, some sort of bonus. if anyone is interested i THINK it is called Waardenburg syndrome, spelling may be off a little.
"He was a beast who lost his fangs, that is why he had to die, Spike...." - Vicious