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Merle Pit Bull Breed Overview: Personality Traits, Temperament & More

MJ Shaffer

Last Updated: November 15, 2023 | 11 min read | Leave a Comment

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Pit Bulls are controversial dogs. It’s hard to find someone neutral in their opinion of the Pit Bull. Love them or hate them, the facts remain the same. They’re not a breed for everyone, and not every individual Pittie is the same. To paint this breed with too broad a brush would be to do them a disservice, but understanding how their popularity has spawned unscrupulous breeding practices will help you make the best choice if you’re buying a Pit Bull puppy.

The American Kennel Club (AKC), the oldest registry in the United States, does not recognize the Pit Bull as a distinct breed but as a type. They only recognize the American Staffordshire Terrier and the Staffordshire Bull Terrier. The United Kennel Club (UKC) and Continental Kennel Club (CKC, not to be confused with the Canadian Kennel Club, which also recognizes them) recognize the American Pit Bull as a breed.

Adding to the controversy in the merle Pit Bull’s case is that this beautiful color disqualifies the dog from being registered by the UKC. This registry recognizes the American Pit Bull as a legitimate breed. Some say the merle gene shouldn’t exist in the American Pit’s lineage, and the parents of a merle Pit could come from an impure line. An additional concern is the unscrupulous practice of breeding merle to merle because of the rarity of the dogs, which may result in homozygous merle pups. These pups often have severe defects such as small eyes with a prominent third eyelid, a physical cleft in the eye’s iris, deafness, or hearing loss.

American Pit Bull
    • weight iconWeight30-60 pounds
    • height iconHeight17-21 inches
    • lifespan iconLifespan12-16 years
    • color iconColorsMerle
  • Child Friendliness
  • Canine Friendliness
  • Training Difficulty
  • Grooming Upkeep
  • Breed Health
  • Exercise Needs
  • Puppy Costs

Breed History

The history of the Pit Bull is the same as that of the Staffordshire Terrier group and the Bull Terrier. The Bulldog, bred for the Bull-baiting ring, was the breed used as the basis for these later fighting dogs. For thousands of years, people have wagered on the outcome of individuals pitted against each other in bloody battles. As far back as 43 A.D., when the Romans invaded Britain, the warring armies pitted fighting dogs against the opposing forces.

The Romans subjugated the British but were impressed with the battle readiness of their dogs. By the early Middle Ages, a rather brutal time in most aspects, dogs were regularly used to bait chained bulls and bears for sport. Not only was this acceptable by the norms of the time, but considered helpful to tenderize the bull’s meat for consumption.

By the early 1800s, economic woes made bulls and bear more expensive, so between the practical considerations and the budding of concern for animal welfare, baiting fell out of favor. In 1835, British Parliament outlawed all baiting. At that point, it was legal and less expensive to fight dogs, and dog-on-dog fighting became the norm.

Before the Civil War, travelers brought these British dogs to the United States to create the quintessential fighting canine – the American Pit Bull. This history still haunts and clouds attitudes against the breed today.

Pit Bull Breeds

The term “pit bull” covers breeds that evolved from the original bull-baiting dogs. Not only does this refer to the breeds recognized by the various registry organizations like the American Pit Bull, American Staffordshire Terrier, and Staffordshire Terrier, but also dogs of pit bull type that may have some outcross, accidentally or on purpose. This outcross can create new color patterns within a breed.

Certain colors and mutations make particular Pit Bull lines more desirable and expensive. You’ll hear about Blue Nose and Red Nose Pits, but the rarest and most expensive variety currently is the merle. If this variety has captured your imagination, you’ll need to understand how genetics determine the pattern and the health problems that can come with the mutation. You’ll also need to understand why this color variety is so controversial.

Color Genetics

Color Genetics In Pit Bulls

Fans of the breed may refer to Red Nose or Blue Nose Pit Bulls. For instance, the Blue Nose Pit Bull carries a genetic mutation to the MLPH (melanophilin), the gene responsible for hair color. Phenotype means outward appearance, while genotype refers to the dog’s genetic makeup. We can’t see genotype, but genotype dictates phenotype, and some phenotypes are very popular and command high prices.

In the case of the Blue Nose, the basic coat color is black. Each parent has two sets of alleles, so they might have two copies of the dominant gene, two copies of the recessive gene (that creates Blue Nose), or one copy of each. If they have one of each, black is dominant to the mutation, so the puppy will be regular color. If you breed two black dogs together, hoping for Blue Nose, you’d have to know if either parent carried that recessive gene. It would take both black parent dogs having the recessive gene and the recessive gene being expressed (there’s a one in four chance if both parents are black noses with a recessive blue nose dilution) to create a Blue Nose pup.

Merle Pattern In Pit Bulls

The merle pattern comes from a more complex set of genetic circumstances. A trait can be dominant or recessive, and we have a pretty clear expectation of how to predict what patterns may appear in the offspring by calculating the odds with a Punnett square. Merle’s mode of inheritance is incomplete dominance. In other words, this is the interaction of genes of both alleles at a locus. Instead of one being completely dominant over the other, they express a blend of traits. A human example is when a couple has a baby. If one parent has curly hair and the other has straight hair, the child’s hair is likely to be wavy, an intermediate between the two extremes due to incomplete dominance.

What makes merle look like merle is that patches of hair have diluted color, while other parts of the dog have regular coloration. Black becomes gray, and brown becomes roan. An individual inherits two alleles for a specific genomic location, one from each parent. If N is regular color (non-merle), the merle allele is ###, which can be any number between 200 and 280. Dogs with N/### or ###/### (heterozygous) will display the merle pattern. How this pattern looks depends on more factors. The amount of dilution depends on which merle alleles are present and if the dog shows black/brown pigment or another variant at MCR1, which is associated with mask, grizzled, and cream variants.

Eumelanic dogs with two copies of ### but smaller numbers show little to no merle pattern and are called “cryptic merle.” The amount of merle pattern a dog shows correlates, when the dog has one or two alleles, to the allele size (as the number approaches 280, size increases). Eumelanic dogs with one or more copies at the high end of the scale display the most dramatic dilution/white pattern. If a breeder crosses two merles, they may produce a homozygous double merle pup with auditory, ophthalmologic, and skeletal defects, among other health problems. Hearing loss and other neurological defects are risks even in a heterozygous merle.


Merle Pit Bull standing outside
Broad-bodied and muscular, his body is bred for power.

His coat is the only difference between a merle Pit Bull and any other color. The presence of the merle gene in and of itself suggests the possibility that the dog is not 100% Pit Bull but has an outcross somewhere in its lineage. Depending on how many generations back the outcross occurred, he could exhibit traits from the source breed of the merle allele.

Adult Pits typically weigh between fifty and sixty-five pounds and stand seventeen and twenty-one inches at the shoulder. A broad head with square jaws sits atop a muscular neck that flows smoothly into the body. Broad chested but athletic, the UKC American Pit Bull breed standard reminds us that bulk should not replace athleticism. The dog must be able to function as a catch dog, wrestle, and hold quarry while breathing easily.

Breed Type And Registration

Your Pit comes from UKC American Pit Bull lineage or AKC American Staffordshire Terrier lineage (these dogs may be registered in the UKC as American Pit Bulls). Some Pit Bull breeders have been breeding for exaggerated traits, although the UKC organization discourages such practices. Breeders trying to capitalize on the negatives of the Pit Bull’s reputation may produce dogs that are too wide-chested, have oversized skulls with overly prominent cheeks, are loose-jowled, and have short, bowed legs. These traits are against the breed standard but part of pop culture’s appeal to the dark side of the Pit.


Excessive shyness or aggression is a serious fault in the American Pit Bull. Dog breeders created the Pit Bull to have the gameness of a terrier with the strength of a Bulldog. Breeders did not tolerate human aggression. Strength, courage, and gentleness with loved ones were hallmarks of the breed. The breed has a natural tendency towards dog aggression and must be carefully socialized by an experienced owner. You must supervise your pup around other dogs and children because of their ability to do damage due to their power.

American Pit Bulls are skilled climbers and need a yard fenced with that in mind. Pit Bulls aren’t natural guard dogs because they generally welcome strangers with a friendly demeanor. Pit Bulls can excel in performance events because of their intelligent and willing nature. They require basic obedience training and an experienced handler due to their strength. Avoid unscrupulous breeders choosing aggression over quality.

Exercise And Training

Pit Bulls need at least an hour of exercise daily to be their best selves. Exercise will keep his body healthy and alleviate the boredom that may channel his energy in a destructive direction. Chew toys for strong chewers are essential, so he can exercise his instinct to chew. If he has too much pent-up energy from inadequate exercise and active play, he may expand his chewing to your furniture or belongings. 

In addition to this, he also needs interactive playtime throughout the day and basic obedience training. Not only does this reinforce your bond with him, but it will also keep him mentally satisfied. Pit Bulls are trainable dogs, but they should be started early and trained with positive reinforcement, not harsh treatment. Train with praise and treats as rewards and consider clicker training.

Socialization is critical when you have a Pit Bull. You must remember that he may harbor an antipathy towards other dogs because of his dog-fighting history. Leashed and supervised interactions with other dogs when he is still a pup will encourage acceptance of other canine individuals. However, instinct is still there and must always be respected. Reputable breeders will begin socializing puppies before sending them home with you.


Because merle is rare, many unscrupulous breeders breed merle to merle to have merle pups to sell. Unfortunately, this practice almost guarantees the birth of some homozygous merle Pit Bulls. These dogs will appear mainly white and are prone to significant health problems above and beyond typical breed issues.


Choose a high-quality formula designed for your pup’s life stage. Feed for moderate growth during his first year to reduce the health risks associated with dysplasia. Feed according to the weight chart on your food brand, and keep an eye on his body condition to adjust his intake as needed. A high-quality kibble including meat protein, fiber, healthy carbs, omega-3 fatty acids, vitamins, and minerals will meet your Pit’s nutritional needs. You’ll be less likely to need additional costly supplements.

Dogs in the Pit Bull family are prone to skin allergies, especially dogs with a lot of white in their coats. If your Pit Bull has frequent ear infections, skin infections, or itchy and inflamed skin, consult your veterinarian to learn more options to manage his allergies through medicine or diet. A limited ingredient or hypoallergenic diet may help keep him comfortable.


Pit Bulls have a low-maintenance coat, but they do shed seasonally. The time of year dictates how much you need to brush them. While he could go days between brushings for the rest of the year, shedding season means a daily once-over with a hound mitt or grooming glove may be necessary to minimize shed hairs. He’ll think you’re just petting him, but you’ll improve the health of his skin by stimulating the production of natural oils and distributing them through his hair coat.

Choose your grooming tools with care. You can manage your Pit Bull’s short, coarse hair grooms with a rubber curry or grooming glove to stimulate the production of oils in his skin. After the initial curry loosens hairs and distributes the oils through his coat, brushing him with a soft bristle brush, in short, quick strokes in the direction of the hair’s growth, makes him shine with health.

Breeders And Puppy Prices

If you’re aware of the potential health problems inherent with merle Pit Bulls and can accept buying a dog you can’t register, find a breeder with a reputation for healthy pups. Merle Pitties can command a premium, with breeders asking over $20,000 for their puppies even though they may be considered crossbreds by many who see them. Some say these puppies are only worth the local shelter’s adoption fee. If you can afford five figures for a puppy, you can afford veterinary care for any health issues he may have, but nobody wants to see their pup suffer from conditions linked to a trendy color.

If you’re wondering how to find a reputable breeder, look for one who will invite you to see the pups and their parents in person. Study their website and make sure they have accurate information about potential health issues. Their parent dogs should have been health tested, and be sure you read reviews from people who have bought their dogs in the past.

Although it is unlikely you’ll find a merle Pit Bull in a shelter because people see dollar signs instead of what’s best for the dog, rescue shelters have more Pit Bulls than any other dog breed. If you love the American Pit Bull breed for its most positive attributes, visit your local rescue centers and see if they have any available dogs that have been tested around other pets and in family situations. Contact dedicated Pit Bull Rescue organizations, and they can help you find an available pup to adopt.

Frequently Asked Questions

Can I Register My Pit Bull With The AKC Or UKC?

Unfortunately, you can’t register your merle Pit Bull with either the UKC as an American Pit Bull or with the AKC, which only registers AKC Staffordshire Bull Terriers.

Does The Merle Pattern Mean My Dog Is Not Purebred?

While there is disagreement over this, the merle gene can exist in a Pit Bull. What makes it unlikely in this day and age is that breeders have put performance at the forefront of breeding goals for years. Individuals with a trait that caused health problems and poor performance were culled. If you see a merle Pit Bull now, there’s a strong chance some other breed was mixed in to add the pattern. As always, buyer, beware.

Do They Make Good Family Pets?

A merle Pit Bull can be a wonderful family pet like any American Pit Bull. You must remember that the breed’s strength makes it imperative that he be well socialized and understand basic obedience commands. No dog should be left unsupervised with small children, regardless of breed.

Are They Illegal?

This depends on your state and local regulations. If laws or regulations in your area or your rental contract restrict what breeds can be pets, “pit bull type” dogs will be included. You must research what is allowed and what is not. Nobody wants to fall in love with a new puppy, only to discover they aren’t allowed to own it.

Final Thoughts

There’s no denying that few dogs are more strikingly beautiful than those with merle coloration. With the color, however, come potential health issues. If you’re buying a merle Pit Bull, you’ve saved up for this puppy for a long time. Be sure you buy your dream pup from a breeder who stands behind their dogs.

Like any Pittie, he can be a loving family companion and a loyal sidekick. Pitties make great exercise buddies who will accompany you on your daily walks or jogs. They also excel as performance prospects for agility or flyball.

A merle Pit is just another color variety of Pit Bull, but the type is rare, costly, and has some additional health concerns to consider. Don’t jump into a purchase; take your time to find a reputable breeder. Be sure to establish a relationship with a veterinarian to keep your beautiful puppy healthy and happy for years to come.

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