Every day, we hear from Embark customers who are surprised by their dog’s breed results. This often happens with mixed-breed dogs that don’t quite look like you’d imagine based on their breed breakdown.
These expectation-defying differences are possible because of how genetic inheritance works. Just like you, your dog gets one set of genes from its mom and another from its dad. If both are carriers of a recessive gene—such as blue eyes in humans—that recessive gene can be expressed in the offspring.
We see this come to life in many dogs tested with Embark, like Max. His owners suspected he was part Rottweiler thanks to his black and tan coat. However, his DNA test showed his ancestry is Labrador Retriever, American Staffordshire Terrier, and German Shepherd Dog. As our Chief Science Officer Adam Boyko explains in the video below, Max’s coloring comes from his Lab heritage. Many Labs carry this black and tan coat gene, but because it’s recessive, it often isn’t expressed. Instead, the dominant black, tan, or yellow coats we associate with Labs are typically seen.
My dog looks mixed, but their DNA test says single breed ancestry
But what if your dog displays the physical traits associated with several breeds and their DNA results say have single breed ancestry?
Take Sunny. His owner thought he was a hound mix, thanks partly to how he barks. But his Embark test showed that he’s 100% Australian Cattle Dog. Sunny doesn’t have his breed’s typical body shape and perky ears. Still, his DNA fits perfectly in the genetic profile of an ACD. Most likely, Sunny is just a non-conforming ACD, meaning he doesn’t meet the breed standard.
Remember that because breed standards exist they aren’t necessarily the rule. Many single-breed ancestry dogs fall outside their breed’s standard. For example, in most dogs, coat length is controlled by a single gene called FGF5. Take the long hair gene which is a recessive gene, so it needs to be inherited by both parents to be displayed. However, that also means that two short-haired dogs can produce a long-haired pup. This explains why we sometimes see long-haired Dalmatians and Pointers, as well as other breeds for which short hair is the standard. That’s genetics at work.
I adopted my dog from a shelter. How can they be a single breed?
Dogs of all kinds—large, small, single breed, mixed breed—can be found at shelters. Plus, many rescues focus on specific breeds, from Golden Retrievers to Bulldogs.
A Yankee Golden Retriever Rescue volunteer told us their dogs are rescued internationally or surrendered by locals. There are many reasons why these Goldens—or any dog for that matter—may be given up. The most common ones for this rescue are financial difficulties, moving, illness of the owner or the dog, time constraints, and allergies of a family member (often a new baby).
Additionally, some dogs that end up in shelters or rescues often don’t meet their breed standard. Shelters typically identify a dog’s breed by looks alone. Visual identification is often unreliable because genes are inherited with many possible combinations. Even trained veterinarians sometimes get it wrong. So just because a shelter tells you a dog is a certain breed or breed mix, genetic data often tells a different story.