People believe they can learn a lot about a dog by knowing his or her ancestry: Is she smart? Will he be big or small? Does he bark a lot? Does she need a lot of exercise? People use a dog’s breed as a guide for how to interact with the dog and how to interpret his behavior. This is problematic even with purebred dogs with documented pedigrees as dogs have been selected primarily for appearance for more than a century. This is rendered even more problematic by lack of accuracy of the breed determination itself, particularly when there is no pedigree or the dog is known to be a mixed breed. Yet shelter workers, new owners, veterinarians, police, and witnesses to dog bites are among the people who may claim to know a dog’s breed, typically based on the animal’s appearance. Research has consistently shown that visual breed identification is most often inaccurate and researchers have known for decades that even first generation crossbreeds usually look dramatically different than either parent (Scott & Fuller, 1960). Moreover, new research (Voith et al., 2013; Croy, Levy, Olson, Crandall, & Tucker, 2012; Olson, Levy, Norby, Crandall, Broadhurst, Sacks, Barton, & Zimmerman, 2015) indicates that even experts have very little agreement when visually determining breed.

Though visual breed identification appears to be cost-effective and immediate, its use is imprudent because it is unreliable and inconsistent. The discrepancies between visual breed identification and objective DNA analysis have strong implications for any research that links breed and behavior. Many scenarios result in a dog’s presumed breed being recorded including arrival at a shelter, veterinary visits, licensing, housing and insurance applications, medical visits following dog bites, and the subsequent media reporting of such incidents. Eventually these unverified breed attributions make their way to databases that are then used in retrospective research studies to make claims about canine behavior. Several studies have sought to relate breed and dog bite-related fatalities. These studies influence public opinion and policy regarding particular breeds. Inaccurate data regarding breed are being propagated, studied, and used to drive policy.

All 5 studies completed so far that specifically address visual breed id (links to summaries and analysis below) bring into question the findings of any studies which attempt to link breed to behavior based on visually identified study populations and demonstrate a need for eliminating visual breed identification as a data source for ongoing canine behavioral studies. 

Voith, V. L., Ingram, E., Mitsouras, K., & Irizarry, K. (2009). Comparison of Adoption Agency Breed Identification and DNA Breed Identification of Dogs. Journal of Applied Animal Welfare Science12(3), 253-262. doi:10.1080/10888700902956151

Voith, V. L., Trevejo, R., Dowling-Guyer, S., Chadik, C., Marder, A., Johnson, V., & Irizarry, K. (2013). Comparison of visual and DNA breed identification of dogs and inter-observer reliability, American Journal of Sociological Research, 3(2) 17-29. doi: 10.5923/j.sociology.20130302.02.

Simpson, R. J., Simpson, K., & VanKavage, L. (2012). Rethinking dog breed identification in veterinary practice. Journal of the American Veterinary Medical Association241(9), 1163-1166.

Hoffman, C. L., Harrison, N., Wolff, L., & Westgarth, C. (2014). Is that dog a pit bull? A cross-country comparison of perceptions of shelter workers regarding breed identification. Journal of Applied Animal Welfare Science: JAAWS17(4), 322-339. doi:10.1080/10888705.2014.895904

Olson, K. R., Levy, J. K., Norby, B., Crandall, M. M., Broadhurst, J. E., Jacks, S., Barton, R. C., & Zimmerman, M. S. (2015). Inconsistent identification of pit bull-type dogs by shelter staff. The Veterinary Journal, 206, 197-202.

Additional References:

Scott, J. P., & Fuller, J. L. (1965). Genetics and the social behavior of the dog. Chicago, IL: University of Chicago Press.  

Croy, K. C., Levy, J. K., Olson, K. R., Crandall, M. & Tucker, S. J. (2012) What kind of a dog is that? Accuracy of dog breed assessment by canine stakeholds. Retrieved from: