Breeds & registries
Merle
A coat pattern that dilutes patches of pigment into a mottled marbling — and a gene with real consequences when two merles are bred together.
Merle works by interrupting pigment production unevenly across the coat, leaving darker patches on a diluted background. It often lightens the eyes and can leave one blue. A single copy produces the pattern and nothing else.
Two copies is the problem. A double merle, from breeding merle to merle, is typically mostly white and carries a high risk of deafness and eye defects including missing or malformed structures. Because the pattern can be nearly invisible on a very pale or red coat, breeders test rather than judge by eye, and merle-to-merle pairings are prohibited by many breed clubs.
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FCIThe international federation of national kennel clubs, which recognises breeds, sorts them into ten groups and lets each breed's country of origin write its standard.AKCThe main US registry, which keeps its own studbook, recognises a shorter list of breeds than the FCI and sorts them into seven groups.Breed standardThe written description a registry holds for a breed — proportions, coat, movement, temperament — and the document judges score against in the ring.BrachycephalicShort-headed — a skull bred shorter front to back, producing the flat face of Pugs, French Bulldogs and Persians.PedigreeA registered record of an animal's ancestors — a family tree issued by a registry, not a guarantee of health or quality.OutcrossingBringing in unrelated animals — sometimes from another breed entirely — to widen a gene pool that has become too narrow to breed out of.