There is often confusion in Europe regarding black & white particolor poodles, which are sometimes mistakenly referred to as harlequin poodles. However, the harlequin gene does not exist in purebred poodles. This gene is found on the H locus, which in poodles is always h/h, indicating that harlequin coloring is impossible in the breed. Additionally, the merle gene, which affects the harlequin pattern in other breeds, is also absent in purebred poodles.

At some point in the past, it is believed that a herding dog carrying the merle gene may have been introduced into a poodle bloodline, leading to the appearance of merle-colored poodles in some lines. This has sparked debate among geneticists and breeders about the purity of such poodles. However, experts in poodle genetics assert that the merle gene cannot exist in the breed, and merle-colored poodles are not considered purebred.

In any case, no poodle possesses the harlequin gene; the multicolor pattern is determined by the S locus and has nothing to do with harlequin. Therefore, black & white poodles are correctly referred to as particolor poodles or abstract poodles, not harlequin. In the United States, where the terminology is well-understood, no organization incorrectly labels black & white particolor poodles as harlequin.