Which White Horse?

I received the photo above from reader Sandy, asking "if it was possibly a White Horse from the White Horse Ranch in Nebraska like the horse's the Anderson family(photo below) have used and promoted so well over the years." The photo is of Ed Seeman mounted on Tarzan during the Circus Days Parade--a forerunner to Conejo Valley Days, dated August 27, 1949. I may be wrong, and please correct me if I am but given this white horse's stouter, thicker appearance it look's to me like it is a Camarillo White Horse and not a White Horse Ranch horse. Again correct me if I am wrong, but I believe White Horse Ranch horse's had an infusion of Arabian blood and tended to make them a bit more refined in appearance. The Camarillo White Horse was predominantly crossed on Morgans giving it the "heavier" look as well as the birth of an occasional "gaited" horse. Ed Seeman seems to be a familiar name to me. Can anybody refresh my memory with more history/information about Mr. Seeman?

Camarillo White Horse Association - Home of the Camarillo White Horses

The “White Horse Ranch”

White Horse Ranch

DOMINANT WHITE

Dominant white is best known for producing pink-skinned all-white horses with brown eyes, though some dominant white horses have residual pigment along the topline. Dominant white is, as the name implies, a genetically dominant color. At least one parent must be dominant white and it does not "skip" generations because it is not recessive. Nonetheless, new variations or mutations producing dominant white do occur spontaneously from time to time. Dominant white is rare, but has occurred in many breeds. It has been studied in Thoroughbreds, Arabian horses, the American White horse and the Camarillo White horse. There are 11 identified variants of dominant white, each corresponding to a spontaneously-white foundation animal and a mutation on the KIT gene. No horse has been identified as homozygous dominant white, and researchers have suggested that at least some forms of dominant white results in nonviable embryos in the homozygous state. While homologous mutations in mice are often linked to anemia and sterility, no such effects have been observed in dominant white horses. Dominant white horses typically have white noses that can be subject to sunburn.

To better understand "white lions" DILUTED COAT COLORS

True white hair is rooted in unpigmented skin that lacks melanocytes. In contrast, diluted coat colors have melanocytes, but vary due to the concentration or chemical structure of the pigments made by these pigment-producing cells, not the absence of the cells themselves. There are at least five known types of pigment dilution in horses, three which, as described below, can act to produce off-white phenotypes. Horses with strongly diluted coat colors usually have pale blue eyes, cream-colored coats, and rosy-pink skin. White markings are usually visible upon closer inspection.

• The Cream gene produces two types of diluted color. Cremellos, perlinos, and smoky creams have rosy-pink skin, pale blue eyes, and cream-colored coats that can appear almost white. These coat colors, collectively called "double dilutes" or "blue-eyed creams", result when a horse is homozygous for the cream gene. When heterozygous, the cream gene is also responsible for palomino and buckskin. A few Palominos have a very light hair coat is occasionally mistaken for either cremello or white. White markings and patterns are visible against the slightly-pigmented coat and skin. The cream gene is not known to be associated with any health problems.

• Pearl-Cream pseudo-double dilute occurs when a horse has one cream gene and one pearl gene. These two distinct dilution factors interact to produce a cremello-like coat. Pearl-creams have pale but pigmented skin and blue-green eyes, and are distinctly pale cream-colored.UC Davis. "Horse Coat Color Tests". Veterinary Genetics Laboratory. University of California - Davis. Retrieved 2008-01-11. "Pearl is known to interact with Cream dilution to produce pseudo-double Cream dilute phenotypes including pale skin and blue/green eyes." To date, the Pearl gene has been found in Quarter Horses, Paint horses, and some Iberian horses. Pearl is not known to be associated with any health problems.

Champagne-Cream pseudo-double dilute occurs when a horse has one cream gene and one champagne gene. Champagne and cream are another pair of unrelated dilution factors that interact to produce a cremello-like coat. Champagne-creams have freckled, pinkish skin, pale eyes, and pale coats. These colors were formerly referred to as "ivory champagnes."