This study showed that shelter staff identified twice as many dogs as pit bulls using visual inspection as were identified through DNA analysis, and that there were frequently disagreements about breed composition among shelter staff.

[Abstract excerpted from original source.]

“Breed identification is used in dog adoption, lost and found, and regulation. In animal shelters, staff members usually assign breed according to what relinquishing owners report their dogs to be or based on appearance alone since most dogs arrive without a known pedigree.¹ Today, there is a negative public perception of pit bulls and labeling a dog as a pit bull can have a negative impact on its adoptability. Sometimes these negative impressions have resulted in bans on owning pit bulls in hopes of guarding public safety. To date, there is no universally accepted definition of a pit bull, nor is there a universally accepted method of breed identification.”