~ You have just entered the White Zone ~


The "S" series alleles appear to be incompletely dominant. In dogs it is thought there are four alleles that deal with white spotting:

~~ "S" - 'solid/self color'. Most dogs that are homozygous for "S/S" have no white hair at all, or possible a tiny amount, like a white tail tip.

We need a photo of a self border collie ( no white at all )

~~ "s^i" - 'irish spotting'. This involves white spotting on most parts of the coat, but not crossing the back beyond the shoulders. This color pattern is evident on the Border Collie that have the white collar.
New research has proven that the white undersides of the Border Collie is dictated by a different gene.

Blade ~ black/white ~ Kyle Lehrmann chocolate merle & white ~ Arnpriors Kennels

~~ "s^p" - 'piebald'. The white is more extensive than irish spotting, and often crosses the back with spots and stripes.

Sydney ~ black/white with a hip stripe ~ Visions Border Collies  Splash ~ chocolate/white ~ Diamond D Border Collies

Chocolate/white pie bald ~ Cathy Saxon

~~ "s^w" - 'extreme white piebald'. A dog that is homozygous for "s^w" will be almost entirely white. This allelic pair is also responsible for the "color headed" white dogs. Often times, along with a colored head, there will also be a colored spot near the tail.

 Duece ~ white & chocolate ~ Visions Border Collies  Flurry - White & Lilac Extreme White Pattern - photo credit: Kim Hastings  Fly ~ white & merle ~ Visons Border Collies

The white factor gene is a simple autosomal recessive and can be carried by a border collie that appears to be non white factored. There is no way to tell for sure until you breed it. In order to control too much white, don't breed two known white factored dogs together, but breed a white factor to a non white factor or breed two non white factored dogs together for the best results.

If you want to control the amount of white, one needs to watch out for white over the shoulder, back & loin areas. The back leg is another way to watch for white factor. You want the white, inside & outside of the back leg, to be below the hock to avoid  producing too much white. The hock is the bend of the back leg. When the white begins to go up the hind leg past the hock, it indicates the dog carries the white factor gene. If you breed two white factored mates together it produces at least some pups that will be pie bald, extreme white or pattern white puppies. Commonly included in high white border collies is the various degrees of excessive white on the head. All excessive white on the head can contribute to deafness. You want the colored area to cover the ears. One needs to be careful and not breed two split faced dogs together as well. Two full colored masked dogs offer the best results of avoiding too much white on the face. 

Deaf Dogs - For info about deafness in dogs

Genome Biology - A site with more detailed information about a study done on the genetics of white

All About Border Collies - Has a page with some white information too