Yet another gene that affects the look of a sheltie’s coat is the typical Irish pattern which includes white markings on the legs, tip of the tail, chest and neck (full or partial ruff) with sometimes a white blaze up the muzzle. The amount of white in each area can vary greatly.
The Irish pattern is what makes Lassie look like Lassie. It’s the coloring that most pet families adore in their Shelties. I have understandably heard plenty of requests for a puppy with a “full white collar” as it is visually appealing.
Flashy Irish is thought to be a combination of Irish and Piebald genetically, as there is increased white.
Some breeders feel that a white collar that extends past the withers (shoulders) is incorrect for the breed and others feel it is a variation of the piebald gene expression instead of the Irish pattern.
is believed that the Irish pattern was brought into the Sheltie breed when
Collie crosses were done. It is also a common
marking of the Border collie as you may know.
Ticking is the gene that creates the appearance of “freckles” on the sheltie white markings. It is a dominant gene.
as you may know, means only a gene from
one parent is required in order to express that particular look.
If you have a yen to delve further into the genetics of coat colors for shelties, I highly recommend Sue Bowling’s page on genetics here. It explores the intricacies of the genetics and subtle difference of expression.
frankly, the simple explanations I’ve given on this website are “broad strokes”
kind of picture. I wanted to offer a relatively easy to understand concept of
how all these colors are possible. Genetics is by no means a simple subject.
As an example: There was a study on domestication of foxes quite a few years back. We all know the normal color and markings of a fox, right? Well, the study involved breeding the foxes in a way that the more docile ones were reproduced and the aggressive ones were not.
After several generations, even though coat color was not of any interest to the researchers and no selection was made for any particular coat color, it was noticed that the fox’s colors were changing.
(There were several other physiological changes in addition to the coat color.)
there are plenty of outside forces that will affect how any one gene shows up.