Does the Merle Color Cause Health Problems? Let’s Clarify.

Too often, we hear or read about supposed terrible diseases associated with Merle-colored French Bulldogs.

With this post, we aim to provide unbiased information supported by reliable scientific data.

First, it’s important to understand that Merle is not exactly a color but a patchy depigmentation effect of the coat. The appearance of the Merle pattern depends on the base color of the dog. The gene responsible for this depigmentation is a dominant gene called “M”, meaning that just one copy in the genetic makeup (Mm) is enough for the trait to appear in the phenotype.

This might suggest that producing Merle litters is easy—but it is far from true. The gene has a potentially lethal characteristic. It is almost never possible to obtain a litter entirely of Merle puppies because two Merle dogs should never be bred together. If two Merle parents were mated, puppies inheriting both Merle genes (“MM”) would likely die in utero or be born with severe malformations incompatible with life.

Clearly, this is well-known, and no breeder with basic knowledge or common sense would ever mate two Merle dogs.

What must be stated clearly is that Merle puppies born from one Merle parent and one non-Merle parent are not less healthy than French Bulldogs of any other color. An Mm dog is not a carrier of any disease caused by its color or genetic status, and its overall health is completely independent of coat color.

Supporting this, we can refer to the article by the renowned geneticist Denis Ferretti, who, despite being critical of new colors—particularly Merle—honestly admits that:

 

“A Merle dog is not inherently less healthy than a dog of the same breed with standard coloration.”

You can read the article here: https://urly.it/35fqm

So, let’s leave the urban myths about Merle aside. Those spreading these stories—whether out of prejudice or personal interest—seek to discredit non-standard colors. The truth is in Ferretti’s article, and I challenge anyone to claim that he is incompetent or biased.

Some might argue that not everyone is an expert, so an uninformed person could mistakenly breed two Merle dogs, risking the death of the puppies. This is true, though highly unlikely: breeders of Merle dogs ensure that puppy buyers are fully informed. Moreover, there is so much media attention and discussion online about this color that it is almost impossible for anyone to be unaware of the risk.

I do wonder, however, why so few people know that breeding caille or fully white French Bulldogs together is extremely dangerous due to the high risk of producing deaf puppies. Perhaps because these colors are considered standard in the breed? But that is another issue…

By Paolo Claudio Rossini fondatore AA Allevatori Arcobaleno

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