Pit bulls get a bad rap, which is especially vexing given that no one actually knows exactly what a pit bull is. There’s no unified definition, because “pit bull” is not a recognized breed. But the label can have devastating consequences for dogs in shelters, who are perceived as less adoptable because of their purported heritage. In recent years, especially with the advent of genetic testing, some researchers have a new idea: just stop labelling mixed-breed dogs altogether.
Researchers at Arizona State University decided to do a large-scale analysis of shelter dogs by looking at every pup that came through the doors of two animal shelters, one in Phoenix, AZ and one in San Diego, CA. Shelter workers were asked to identify the primary and secondary breeds of each dog (or simply “mixed breed” if it was too heterogeneous), as is standard at most American organizations, and scientists took cheek swabs from each to test their genetic heritage. They published their results in the journal PLOS ONE.
Not only were shelter workers relatively inaccurate with their breed labels, according to the data, but even correctly-identified dogs generally got less than half of their genome from the so-called primary breed. Dogs correctly ID-ed as pit bull mixes were on average only 38-48 percent “pit bull,” here defined as having some heritage from an American Staffordshire Terrier, an American Bulldog, a Bull Terrier, or a Staffordshire Bull Terrier. The same was true for other breeds. Chihuahua mixes were generally about 38 to 39 percent Chihuahua. Poodle mixes were only around one-third Poodle.
Categories Dogs & Animals