Tracking Merles: 10 years later. (Updated)

A tool not a solution.

© Jean A. Delisle

1874 Kennel Club (UK) Stud Book

Numbers create clarity and commitment.
Numbers create accountability.
(from "What the heck is OES?" By G. Wickman, T. Bouwer)

In 2010, the American Spaniel Club (ASC) the parent club for the Cocker Spaniel (or American Cocker Spaniel in the rest of the world) and the primary guardian of the Cocker Spaniel breed, embarked on a mission with AKC (the American Kennel Club is responsible for dog registrations in the U.S.A.) to create a Z registry in order to identify Merle cocker spaniels. In May 2011, the ASC members votes over 80% to approve the creation of the Z Registry. As of July 2011, Merle is now a registerable pattern for cockers with AKC.

As a consequence, any offspring of any Z registered Cocker (sire or dam) would automatically be registered with a Z designation - no matter the color or lack of marking/pattern. And their offsprings will all be registered with a Z designation and so on and so forth. It was thought that Z registered dogs would greatly increase the ability to track these Cockers in pedigrees and isolate those dogs from breeding with the promises of breeders education.

The Stud Books are an excellent source and most important tool for accurate information about a breed. It is the official record of the pedigree of purebred animals, a record of the lineage. They document the first time any registered dog (male or female) is used to breed a registered litter of purebred dogs.

I believe the first official (Z) Merle entry is in the June 2012 AKC Stud Book: Lilly Of Merle, SZ00001404, a black bitch with merle markings born on Sept 18, 2010. The first Merle male is in the September 2012 Stud Book Wyndsong's Blue Eyes Over Texas, SZ00003601, a Black/White/Tan dog with merle markings born on November 8, 2009.

For the year 2012, 4 Merles were in the Stud Book out of 1,356 or 0.29% of all new entries. Fast forward 7 years later, Merles account for 17.46% of the total dogs entered in the Stud Book for 2019.

At the end of 2020, merles represent now 22% of all entries in the AKC Stud Book for cocker spaniels.

2012 · 2020

Merle is a pattern of coloring observed in the coat of the domestic dog and is characterized by patches of diluted pigment. This trait is inherited in an autosomal, incompletely dominant fashion. Dogs heterozygous or homozygous for the merle locus exhibit a wide range of auditory and ophthalmologic abnormalities, which are similar to those observed for the human auditory - pigmentation disorder Waardenburg syndrome. (Retrotransposon insertion in SILV is responsible for merle patterning of the domestic dog)

Jean Delisle is a Canadian Kennel Club Sporting & Toy Group judge. Member of the American Spaniel Club Archival Work Group. Maintain and update the Cockers-Worldwide Pedigree website. He bred American Cocker Spaniels under the prefix Kebec's with Pierre Talbot since the early 1980s.