Merle coat pattern(M)
Also known as: Merle-Faktor · M-Lokus · PMEL gene mutation · Dapple gene · Merle Ocular Dysgenesis · …
Overview
What it is
The merle coat pattern is caused by an autosomal-dominant mutation in the PMEL gene, which affects pigment-producing cells in the skin, eyes, and inner ears. When a dog inherits two copies of this gene, a condition known as double merle, it disrupts the normal development of these sensory organs. This genetic defect can lead to severe structural abnormalities in both the auditory and visual systems.
How it presents
Double merle puppies are typically born with an excessively white coat and may show signs of partial or complete deafness and vision impairment from birth or early puppyhood. Owners may notice that the dog does not respond to sounds, has abnormally small or misshapen eyes, or struggles to navigate its environment.
Treatment
The genetic deafness and blindness associated with this condition are incurable, requiring lifelong supportive care, specialized training, and regular veterinary monitoring. Managing these sensory deficits and associated eye conditions typically costs between 1,000 and 6,000 EUR over the dog's lifetime.
How it's tested
Labogen Komplettpaket (rassespezifisch)(Labogen-Panel)
Primary testDNA testRassespezifisches DNA-Panel (Labogen / Laboklin) — bündelt alle relevanten Erbkrankheiten der Rasse in einem Test.
Issuing body: Labogen
Result scheme: Clear/Carrier/Affected
Merle-Lokus DNA-Test(M-Lokus)
Primary testDNA testDer DNA-Test identifiziert die SINE-Insertion im PMEL-Gen, um den Merle-Status und die genaue Allellänge zu bestimmen, was für die Zuchtplanung zur Vermeidung von Double-Merle-Welpen entscheidend ist.
Issuing body: Labogen
Result scheme: Clear/Carrier/Affected
Feragen Komplettpaket (rassespezifisch)(Feragen-Panel)
DNA testRassespezifisches DNA-Panel (Feragen, Österreich) — gleiches Konzept wie Labogen.
Issuing body: Feragen
Result scheme: Clear/Carrier/Affected
Embark Breed + Health Panel(Embark)
DNA testUS-Anbieter; 250+ genetische Erkrankungen + Abstammung. Anerkennung in DE/AT variiert je nach VDH-Verein.
Issuing body: Embark
Result scheme: Clear/Carrier/Affected
MyDogDNA Panel(MyDogDNA)
DNA testGenoscoper-basiertes Panel (Mars Petcare). 200+ Erkrankungen + Rassenkomposition.
Issuing body: MyDogDNA
Result scheme: Clear/Carrier/Affected
Affected breeds
14 of 14 breeds
Mandatory testAmerican Leopard Hound
Mandatory testBergamasco Shepherd Dog
Mandatory testBorder Collie
Mandatory testMudi
Mandatory testRough Collie
Mandatory testShetland Sheepdog
RecommendedAlpine Herding Dog
RecommendedAmerican Collie
RecommendedAustralian Shepherd
RecommendedCatahoula Leopard Dog
RecommendedDunkerhund (Dunkerbracke - Norwegian Hound)
RecommendedPembroke Welsh Corgi
OptionalGreat Dane
OptionalMiniature American Shepherd
Why is this linked to extreme breeding?
This condition can be tied to a trait dogs are bred for. These pages explain how it arises, which breeds are affected and how to recognize dogs bred for health.
Treatment cost
Estimated range of typical treatment costs. Actual costs depend on severity, clinic and region.
Frequently asked questions
What is Merle coat pattern?
The merle coat pattern is caused by an autosomal-dominant mutation in the PMEL gene, which affects pigment-producing cells in the skin, eyes, and inner ears. When a dog inherits two copies of this gene, a condition known as double merle, it disrupts the normal development of these sensory organs. This genetic defect can lead to severe structural abnormalities in both the auditory and visual systems.
How is Merle coat pattern tested?
Tests currently in our database: Labogen Komplettpaket (rassespezifisch), Merle-Lokus DNA-Test, Feragen Komplettpaket (rassespezifisch), Embark Breed + Health Panel, MyDogDNA Panel.
Which breeds are most affected?
Most commonly affected: American Leopard Hound, Bergamasco Shepherd Dog, Border Collie, Mudi, Rough Collie, Shetland Sheepdog, Alpine Herding Dog, American Collie.