BREED STANDARDS are common in most domestic breeds of animals where breeders use pedigrees and registries to track purebreds. A breed standard should be set at the BEGINNING of a breed's development, to guide breeders in the selection of stock as they breed forward-- the goal should be to breed toward the ideal according to the breed standard-- otherwise, its every breeder just breeding what they like in their own vision of what they think the breed should be. In my observation, lack of and/or lack of enforcement of a consistent Appaloosa breed standard, beyond bloodline and color requirements, is in great part what has caused confusion and splintering among Appaloosa breeders.
Here are Appaloosa breed standards from various registries which register Appaloosas according to their own specific rules-
Here are Appaloosa breed standards from various registries which register Appaloosas according to their own specific rules-