Sweet mutts with "pit bull" in their description wait at shelters three times as long as differently labeled lookalikes, according to a new PLOS ONE study. Labels might be inadvertently penalizing shelter dogs, and removing them altogether could be a relatively low-cost way to improve the dogs' outcomes. 

Previous work found that certain types of dogs take longer to be adopted. Those labeled as pit bulls were the most prevalent breed available for adoption and the most commonly evaluated in U.S. animal shelters. These often include American and English bulldogs, Staffordshire bull terriers, American Staffordshire terriers, and American pit bull terriers, as well as mixes of these. 

A shelter dog’s breed has been linked to varying outcomes – including longer stays and increased euthanasia – but the breed is often designated based on appearance (which can be misleading) or the relinquishing owner’s report. And many discrepancies have already been found between visual identification and DNA analyses. "This intersection of research and curiosity about how breed assignment could influence potential adopters’ decisions motivated us to conduct our studies," Arizona State University’s Lisa Gunter told IFLScience. 

^{From L.M. Gunter et al., PLOS ONE 2016. Arizona Animal Welfare League}

Gunter and colleagues conducted a series of tests to see how we perceive the behavior and adoptability characteristics of pit bull-type dogs. First, they used surveys to assess the perceptions people have of pit bulls compared to Labrador retrievers and border collies. Then they analyzed the impact of the "pit bull" label by looking at lengths of stay and perceived attractiveness – that is, friendliness, aggressiveness, and intelligence – compared to differently labeled lookalikes. They did this using photos and video recordings of pit bull-type dogs and lookalikes, both with and without breed labels. And finally, they analyzed data from an animal shelter that stopped applying breed labeling on their kennels.

Breed labeling, they found, influences perceptions and potential adopters' decision-making. Pit bulls were perceived as less adoptable than other breeds, and they were considered less friendly and more aggressive. Compared to lookalikes that were unlabeled or labeled as other breeds, dogs with "pit bull" labels waited over three times as long to be adopted.

"We were surprised how very similar looking dogs sometimes get labeled ‘pit bull’ and other times as something completely different," Gunter said in a statement. "These dogs may look and act the same, but the pit bull label damns them to a much longer wait to adoption."