Judging a dog by its cover: The dangers of breed misidentification
Guesstimating a canine veterinary patient's breed by its look alone is unreliable and can have serious consequences in some cases.
GETTY IMAGESWhy they did it
Dog breed identification has long been a part of veterinary school education and daily clinical practice, as well as a key component of animal assessment in many shelters and rescue programs. Given the evolution of canine breeding practices over the years, however, the classic characteristics and behaviors once attributed to a specific breed cannot be reliably identified in individual animals. One article's and two studies' authors have posited that relying on breed identification based solely on physical appearance may in fact lead to greater confusion and misclassification.
What they did and what they found
In the first article (Simpson, et al) the authors note that “physical appearance does not appear to be a good indicator of breed when dealing with dogs of mixed breeding.” As support, they cited two previous studies, the first of which demonstrated that puppies of cocker spaniel-basenji crossbreeding had wide variations in color and conformation and did not resemble the breed of either parent.1 The second cited study compared the results of visual breed identification with DNA analysis of breed in shelter dogs and found correlation for only 25% of the dogs.2
Given the reliance that is placed on breed identification in a variety of veterinary settings, breed misidentification can have a negative impact across a variety of situations, such as owner expectations after adopting a shelter dog, homeowner insurance coverage and rates, local legislation regarding breed ownership, airline transport of certain breeds, and child adoption or foster placement decisions. Thus, as an alternative to breed identification, the authors propose that veterinarians use nonbreed-based terms (e.g. mixed-breed dog) to describe dogs of unknown parentage, regardless of physical appearance. Instead, a physical description or photo of the patient, or both, should be included in the medical record.
The authors also note that DNA analysis for breed identification is still subject to error given the limited genetic diversity of dogs; however, with a stated mean accuracy between 84% and 90%, DNA analysis should be considered in lieu of a guess if the owners request identification of the predominant breed in a dog of unknown lineage.
In a separate study on a related subject, a national survey conducted by the College of Veterinary Medicine at the University of Florida (Croy, et al) found that, among 5,922 respondents, the correct predominant breed was identified from photographs only 27% of the time. Breed was considered correctly identified if a breed that represented at least 25% of a dog's genetic makeup-as assessed by DNA breed profile-was chosen. It is interesting to note that respondents were all self-described “dog experts” and included veterinarians, breeders and trainers. The authors note that the results indicate that visually identifying breeds of dogs with unknown heritage is unreliable, that incorrect breed identification may have long-term consequences-particularly where breed-specific regulations or prohibitions exist-and that a different way to describe dogs' appearance should be developed.
Finally, a 2014 study among shelter workers in the United States and the United Kingdom (Hoffman, et al), found that most of participants used only the dog's physical features to determine the predominant breed. In light of the creation of breed-specific legislation (BSL) regarding pit bull terriers in recent years, participants were questioned specifically about this breed. The authors found that 41% of participants who worked in shelters subject to BSL admitted that they would knowingly mislabel a dog as something other than a banned breed, such as a pit bull terrier, presumably to increase dog's opportunities for adoption. The authors note that these findings “bring into question the validity of determining breed identity based on appearance” and “highlight some issues regarding the practical utility of BSL.”
Simpson RJ, Simpson KJ, VanKavage L. Rethinking dog breed identification in veterinary practice. J Am Vet Med Assoc 2012;241(9):1163-1166.
Croy KC, Levy JK, Olson KR, et al. What kind or dog is that? Accuracy of dog breed assessment by canine stakeholders. Published by College of Veterinary Medicine, University of Florida, Gainesville.
Hoffman CL, Harrison N, Wolff L, et al. Is that dog a pit bull? A cross-country comparison of perceptions of shelter workers regarding breed identification. J Appl Anim Welf Sci 2014;17(4):322-339.
Link to article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160292
1. Scott JP, Fuller JL. Genetics and social behavior of the dog. Chicago: University of Chicago Press, 1965.
2. Voith VL, Ingram E, Mitsouras K, et al. Comparison of adoption agency breed identification and DNA breed identification of dogs. J Appl Anim Welf Sci 2009;12:253-262.