Appaloosas that carry the LP gene have three basic characteristics:
Sometimes at birth, some of these may be subdued and develop more with age. Mottled skin is most often seen where there is no hair, or the hair is very thin, such as the muzzle, around the eyes, under the tail, and on the sheath or udder. The eyes have white sclera encircling the iris like a human eye. The hooves have vertical striping such as is shown in the photos below.
Horses who look phenotypically solid will be registred in the Non-Characteristic Division unless they show these three characteristics, or test postitive for LP. You may need to show clear photos of these three characteristics when registering a horse who's Appaloosa coat pattern is missing or marginal.
See photos below of the three characteristics. In the next section you will see the effects of the LP gene in it's homozygous form on the color of the hooves.
NOTE: Horses do not have Appaloosa striped hooves on legs with white leg markings. If they have striping, it is the result of ermine marks at the coronet band (see last section).
Chelseas Honey Whirl F2-2743, Mottled Skin and White Sclera
When a horse is homozygous for the LP gene (LP/LP), many times the hooves are a shell color with very light striping, even on horses with black legs, such as in the photos below.
BCA Tofoz Fudasan F5-2637
Some horses with white leg markings have ermine marks. If there is any color pigment that touches the coronet band, it can send dark stripes down into the hoof. These are not Appaloosa striped hooves.