Unraveling The Mysteries of Merle


This PDF download is an article I wrote for The Australian Shepherd Club of America. 
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The following statics are taken from on online survey of Aussie breeders and owners.

Percentage of m/m - Non-Merle - 43%

Percentage of dogs having a shorter Non-Expressing allele of Mc, Mc+ or Ma - 57%

38% of phenotypically solids dogs are either m/Mc or Mc/Mc. These dogs will breed the same as non-Merle. When bred to an M - Merle mate no pigment will be deleted to white.

19% of phenotypically solids dogs have either an Mc+ or Ma allele which can delete pigment to white when paired with M.


The following is a chart comparing those percentages to data provided by Tilia Laboratories which includes 785 Merle tested dogs from all breeds worldwide.

Out of those 785 dogs a total of 286 are non-Merle in phenotype - 146 are m/m and 140 have shorter non-expressing alleles.