As a teenager I read any book I could get my hands on that had any sort of
equine connection what so ever, including a lot about different breeds. I still
love horse back riding, and hope to get a horse of my own some day, when my
time and economy allows... I don't know if this contribution is useful, but it
would be nice if all those misspent hours of my teenage life could somehow
benefit somebody...
So, while I'm no authority, I agree with Draupne: There are no non-albino
horses that are entirely pure white. Even the Lippizans of the Spanish Riding
School in Vienna are not _stricly_ white when they grow up, just very, very
pale grey. And yes, they are dappled, even if the pigment aggregation isn't
always very pronounced. I don't believe there are any uniformly grey, undappled
horses. I welcome corrections from more knowledgeable people, of course!
When I first read LotR I was still at my most horse-fanatical, and I remember
deciding that Snowmane had to be an albino, while Shadowfax was a light silvery
dappled horse, "skimmel" in Danish. Of course albinos tend to have bad
eyesight, which might not be very practical in a war horse!
(The technical difference between "very, very light grey" and "white" would be
the absence vs. presence of pigmentation in both the hair and skin, and
"dappled" indicates that the pigmentation is not uniformly distributed, but
aggregated in
spots...)
A Túrin Turambar turún' ambartanen
-Master of doom by doom mastered