The "mixed breed" category reflects a portion of the dog's genome that is more genetically diverse, and therefore not easily attributable to any particular breed. This is because dogs can have ancestors that were also mixed breeds. These mixed breeds are typically the result of dogs breeding freely, in comparison to human involvement through the selective breeding of dogs for specific characteristics. The genetic diversity of these dogs allows for a wide range of phenotypes (observable expressions of traits)
Mixed breed dogs have a more diverse gene pool, which typically results in fewer genetic disorders getting passed down from generation to generation. The chances of any two random mixed breed dogs having the exact same genetic mutations is very low in comparision to any two purebred dogs of the same breed. However, genetic testing is still recommended for mixed breed dogs to assist veterinarians with diagnosis and proactive care.
Mixed breed dogs can have a wide range and variety of observable traits and behaviors.