Merle is a genetic pattern that produces patches of darker color on a lighter background, often with ticking (small spots) and blue eyes. Because merle acts as a color diluter, it can lighten the base coat. When a dog’s primary color is white, merle often shows up as heavy ticking on the white areas.
Although merle is clearly hereditary, researchers haven’t pinpointed a single gene responsible. At first, merle was thought to be controlled by one dominant gene, but now it appears to involve multiple genes working together. That complex interaction explains why merle can skip generations and show up unexpectedly in some litters.
History of the Merle Pit Bull Terrier
Merle has been part of Pitbull history since the breed’s earliest days. When the American Pit Bull Terrier earned its first formal recognition, breeders like John Colby kept merle dogs. In Louis Colby’s “Colby’s Book of the American Pit Bull Terrier” (1922), a famous merle female named Goldie appears in a photo with John and young Louis Colby. Other early references to merle appear in Richard Stratton’s breed books.
Over the years, some people have tried to dismiss Goldie’s photo as “Colby’s Goldy,” a different dog entirely. But Louis Colby himself never corrected the image in later editions. He even refused to change it when persuaded that an error might make his book more valuable. Documentary evidence and side-by-side photo comparisons confirm that Goldie was indeed a merle Pitbull.
In 1936, the first written breed standard for Pitbulls stated, “Any color, solid, parti, or marked is acceptable.” Fourteen years later, the American Kennel Club’s standard echoed the same openness: “Any color or marking is permissible.” Those early rules prove that merle was an accepted color for Pitbulls—long before modern debates began.
The Merle Controversy
In recent decades, some registries have stopped recognizing merle Pitbulls despite decades of historical acceptance. This shift often comes down to a few influential individuals who criticize merle based on their own biases. One prominent opponent of merle supports heavy inbreeding, even though many health problems blamed on merle actually stem from tight inbreeding.
Critics sometimes call merle “impure” or “mixed,” but no solid evidence links merle to other breeds. If you argue that introducing merle “dilutes” purebred Pitbulls, then by that logic every dog breed would be in jeopardy—because all dog breeds have some history of crossbreeding. Even the United Kennel Club acknowledges that many historic Pitbull lines carried genes from other bulldog-type and terrier-type breeds. Removing merle would mean erasing hundreds of years of documented variety.
Health Considerations for Merle Pitbulls
Since 2005, the American Pit Bull Registry (APBR) has reviewed health claims about merle Pitbulls to separate fact from fiction. After a decade of study—examining written records, old photographs, and lineages—APBR found that merle Pitbulls do not suffer more health issues than non-merle Pitbulls when responsibly bred.
Merle is a dilution pattern, so breeding two merles together can produce “double merles,” which carry a higher risk of vision or hearing problems. Because of that, most experienced breeders pair one merle with a non-merle to avoid double dilution. A few breeders have safely bred merle-to-merle with careful testing, but those litters require close monitoring and a willingness to manage any potential health challenges.
In our research, we also found cases where a merle gene skipped generations before reappearing in a litter. This confirms that merle can hide for several generations, and why breeders must rely on DNA testing rather than appearance alone.
Merle Pit Bulls Today and Tomorrow
Despite ongoing controversy, merle remains part of the Pitbull’s documented history. The APBR believes it would be unethical to rewrite that history or erase a color that’s been recognized for nearly 100 years. Every Pitbull line has faced challenges—reds, whites, blues, and merles each had times of doubt. If breeders let personal bias dictate which colors to accept, the entire breed would risk losing its rich diversity.
True Pitbull fans and owners embrace this variety. In a country that values freedom, it’s unfair to deny anyone the choice to own a merle Pitbull. Climate, local laws, and personal preference will always influence whether someone picks a merle dog, but no one should try to ban merle altogether.
At APBR, we celebrate the merle Pitbull’s future. With responsible breeding—meaning health testing, minimal inbreeding, and ethical practices—merle Pitbulls will continue to thrive as part of the breed’s vibrant legacy.
