Horse breeding
Since the relaxation of the white rule, at least one registered Quarter Horse has tested homozygous for the SB1 allele. Due to this example, as well as the extensive Quarter Horse breeding present in Paint bloodlines, it is clear that the SB1 allele exists in the breed's genepool and that there have been SB1 sabinos that had minimal markings classified as "solid". Quarter Horses may exhibit sabino-like patterning from the same genetic sources as other breeds.