basic Introduction to the splash white pattern gene

Splash is a variable white spotting pattern that makes the horse look as if it were dipped in white paint and it exists in the Morgan breed in rare numbers. The splash gene produces white stockings, large white blazes, blue eyes, belly markings, and interestingly, in heterozygous (one gene carriers) there can be no white at all.

The splash gene "hides" only in the context that it isn't always visually obvious. It doesn't skip generations or express only on specific base colors. If you suspect a horse carries splash, DNA color testing for Splash 1 confirms whether or not it is present. The 3 identified lines that currently exist in the breed are:

1. Marvelous line back through Royal-Glo to Selims Best to Byrrh (1913)

2. Sweets line back through Lady In Lace to Rose Bay to Byrrh (1913)

3. King Blaze Mint line back through Icestone Whitewing 

If a horse has one copy of the splash gene and it is mated to a non-splash Morgan the resulting foal will have a 50% chance of inheriting one copy of the splash gene, 50% will have no splash gene at all.

If a Morgan has one copy of the splash gene and it is mated to a Morgan with one copy of the splash gene, there is a 50% chance of inheriting one splash gene, a 25% chance of inheriting two splash genes, and 25% no splash gene at all. 

If a Morgan has one copy of the splash gene and it is mated to a Morgan with two copies of the gene there is a 50% chance the foal will inherit two splash genes and 50% it will inherit one splash gene. This pairing is better but still only 50% odds for a homozygous splash.

If both Morgans have two copies of the splash gene the resulting foal will have two splash genes and breeders are assured the white pattern will express maximum pattern. This 100% homozygous pairing is the ideal scenario for a breeder to get foals with pinto patterns. It is also the most difficult to get.

It is very difficult, and often takes a breeder years, to produce a homozygous splash foal with maximum white pattern expression. When these foals are born, because they are so rare (less than 20 in the breed), they are not inexpensive and they are not sold on the open market often. As the number of Morgan horses possessing the splash gene increases, the breed may see more pinto marked Morgans and prices may eventually come down too. That will take many years to accomplish with breeders who have a passion for more white pattern in the Morgan breed. 

There are other lines in the breed that are believed to have yet-to-be identified white pattern(s). As science evolves those genes may be identified and we can learn more about how and when they express in white patterns. 

W20 (dominant white) also exists within the breed. W20 causes variable white patterns and on its own does not add white. It can greatly increase the amount of white when it is combined with other white pattern genes. 

 Our goal is to increase the number of quality splash Morgans with proven ancestry and the "icing on the cake" will always be foals that are homozygous splash that is 2 copies of the splash gene.  

There is no such thing as a bad Morgan horse color but white markings are appealing, unique and fancy.