Here is a link to the Paint Horse Association book on color genetics. That I just found!
Some people have observed that
many splashed white horses are
deaf. This is not much of a problem
if the trainer realizes the limitations
of the horse in question and modifies
the training program to meet
the horse’s special needs. Many of
these horses go on to lead normal
and productive lives.
Because no homozygous
splashed white horses have ever
been documented, researchers suspect
that this is another gene that
cannot exist in homozygous form.
If this is true, the loss of hearing
probably occurs early in gestation
rather than at term. Because of this,
the best strategy for producing
splashed white horses is to mate
them to horses without the
splashed white pattern.
Color Pattern