Hello Kathy-
EXCELLENT question / point!  In my research & estimation this is a BAD
cross.  The same has been done in for example Blue merles of the collie,
and sheltland sheepdog species.  The results of double cross MUCH HIGHER
rtate of deafness, blindness, dwarfism adn other anomalies which would
fall in line with the understood Waardensburg symdrome.
 
I once knew a breeder who did such a cross in dogs and she ended up
freezing the young blind pups to erradicate the evidence of her poor
breeding judgement.  NO, I was not impressed!
 
Caution in breeding any animal must be taken.  It is necessary (my opinion)
to be familiar with the past history back 5 generations to know which genes
can be recessive.  Once the offspring arrive a breeder must be ready to
accept the kits flaws or not!.
[Posted in FML issue 3208]