merle
n. C / Un. a pattern in a dog's fur that looks like patches of different colors mixed together. It is most common in breeds like Australian Shepherds and Great Danes.
n. a genetic pattern in a dog's coat that produces mottled patches of color in a solid or piebald coat. Often associated with specific health issues if two dogs with this pattern are bred together.
The puppy has a beautiful blue merle coat.
Breeders must be careful when working with the merle gene to avoid hearing and vision problems in the litter.
The striking appearance of the red merle pattern is highly sought after in working breeds, though it requires rigorous genetic testing to ensure the health of the offspring.
From French Merle.
English 19th-century bird name from merle (“blackbird”), possibly also a variant of Muriel, Merrill, etc.
Used as an uncountable noun for the pattern itself and as a countable noun when referring to a specific dog with that coat.