Yes, there are purebred Arabs with lots of white! If you’ve got one which qualifies, consider the Sabino Arabian Horse Registry; there’s also a Sabino Horse Registry for all breeds, as well as the Blue-Eyed Horse Association…
Again with the coat colours: there’s also the Brindle and Striped Horse International Registry…
Recently stumbled across this page-in-progress for the Baroque Pony Registry; don’t know if it’s going to get off the ground, but the pictures are great…
Not purebred? Your critter might still qualify for the American Part-Blooded Horse Registry or the American Grade Horse Registry…
The American Indian Horse Registry honours the horse of the Native American Nations, their hybrids and descendants with 5 classifications of registration…
The Canadian Livestock Records Corporation maintains online studbooks for the following horse breeds (as well as other critters): Canadian Horses, Clydesdales, Donkeys & Mules, Fjords, Hackneys, Haflingers, Icelandic Horses, Miniature Horses, Morgans, Percherons, Peruvians, Saddlebreds, Shetland, Dartmoor, Fell, Highland, Riding & Polo Ponies, Sport Horses, Warmbloods, and Welsh Ponies & Cobs.
Bridlepath 