The white gene is also carried independently of color.
Now pay attention. White in the Collie is not so much as a color as a
condition just like the dilution gene we just went over. The white Collie
does come with a color that is inherited just like a non-white collie. In
the white though, the only place you usually see the color is on the head
and maybe a body spot or two. That is why they are called...a sable-headed
white, a tri-headed white..and so on. The white means that they inherited
the white gene and can produce a white.
White Collies are not rare and can easily be produced
when bred to another White Collie, or crossing a white-factored Collie to
another white factored collie, (which results in about one in every three
puppies born being white). A white-factor is a dog that carries the white
gene, but is not white itself. It can usually be detected by the large white
collar and the unique marking on the back leg. The white extends in an
unbroken line all the way up the inside of the back leg and is visible by
looking at the dog from the side.
White Collies are healthy - meaning the White gene
itself does not affect the health. This is not to be confused with a “Double
Dilute” white Collie.
 These
can have health problems and are often born without eyes or deaf. They also
suffer from internal problems such as liver and kidney problems and if they
live through the first few weeks, usually die at an early age because of the
internal problems. There have been many Double Dilutes that have been grown
out and lived long and productive lives, but this is the exception. If bred,
it can only produce a Merle. The Double Dilute can only occur when two
Merles are bred together and that offspring inherits a Dominant dilution
gene from each parent..thus the Double Dilute.
To learn more about Collie Color inheritance patterns a
good book, "COLLIE CONCEPT" by Bobbie Roos is recommended. It was published
by Alpine Publications in 1988 and can be order from your bookstore or on
the net.
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