09/28/2026
Does breed still matter in a mixed-breed dog?
Absolutely—but it isn’t a perfect recipe.
A DNA test cannot guarantee exactly which behaviors a dog will display. Genetics are inherited in combinations, not neatly divided according to the percentages on a screen. Two puppies from the same litter can inherit different physical and behavioral traits despite having the same parents.
However, breed still matters because breeds were selectively developed for specific purposes. Herding, hunting, guarding, retrieving, controlling vermin, and working required different drives, instincts, physical abilities, and temperaments.
When breeds are mixed, those genetics do not simply disappear. You may see traits from the largest percentage, smaller traces from several breeds, or a surprisingly strong characteristic from a breed that makes up only a small portion of the dog’s ancestry.
Peanut is a perfect example. His DNA results are:
• 58% American Pit Bull Terrier
• 22% American Staffordshire Terrier
• 5% Boxer
• 4% Labrador Retriever
• 3% Rottweiler
• 3% Staffordshire Bull Terrier
• 2% Bulldog
• 2% Bullmastiff
• 1% Doberman Pinscher
That makes Peanut overwhelmingly a bully-breed dog, and many of his natural characteristics reflect that.
He is extremely intelligent, athletic, strong, determined, prey-driven, and naturally prone to resource guarding. He loves people when he feels like it, but most of the time he is fairly indifferent toward them. He also absolutely loves the water—maybe that little bit of Labrador Retriever decided to show itself there.
Interestingly, Peanut doesn’t really care about playing with toys. His favorite activity is obedience. He genuinely enjoys working and becomes a completely different dog when we train. Outside of work, he may perform a command as half-assedly as possible while practically rolling his eyes at me.
Peanut is also extremely dog-selective and is not safe with small dogs. Training has allowed him to be successfully introduced to several appropriate dogs of different ages, breeds, sizes, and genders without a muzzle, but that does not mean he should interact with every dog. It also doesn’t mean his genetics or natural tendencies disappeared.
Training taught him how to control himself, make better decisions, and coexist successfully under clear expectations. It did not transform him into a dog-park dog—and that was never the goal.
Not every pit bull-type dog will display the same traits Peanut does. Genetics, early development, previous experiences, environment, training, and reinforcement history all contribute to the individual dog standing in front of you.
That is the important distinction: genetics can influence behavior, but they do not eliminate a dog’s ability to learn.
Breed gives us useful information about what a dog may be naturally inclined to do, what outlets may fulfill them, what challenges could appear, and which behaviors an owner should be prepared to manage.
The individual dog still matters most—but pretending breed is irrelevant does dogs and owners a huge disservice.
Breed is not a guarantee, an excuse, or a life sentence. It is one important piece of the entire dog.