In a new study that was just released, researcher Victoria Voith once again exposes the challenges of identifying dominant breeds of mixed breed dogs, even by "experts" in the field. I think the research is important for a lot of reasons (some different from what others have surmised), and worth reviewing as the world of DNA genetics testing continues to challenge what we think we know about canine genetics, and rapidly adding knowledge to the field.
The Study
In the study, more than 900 people who had professions in the field of animal welfare were asked to watch a 1 minute video of 20 dogs that showed the full view of the front and side of the dog, along with the weights, age, and sex of the dogs. All participants noted that they're breed identification was sometimes used for record keeping purposes and were largely made up of kennel staff, Veterinary Assistants, Animal control Field officers, dog trainers, or other animal control or veterinary/behavior triaining staff.
The survey participants then had to answer the following questions:
Do you think the dog is purebred? yes/no
If yes, what breed to you think it is?
If No, what do you think is the most predominant breed?
What do you think is the second most predominant breed? If you are unsure, write "mix".
The answers were then compared to the DNA results for the dogs.
The Dogs
Before I get into the results for this, I want to discuss the dogs used, and DNA as a whole. It's very important to note that at this point no one is saying that DNA tests are 100% reliable. Even the researchers who are creating the tests note this. Currently, the Mars Wisdom Panel test (which was used for this analysis) says it has a 90% accuracy rate across all first generation crosses. As dogs get further removed from pure heritage, the results get less and less accurate.
It's very important to note in this study that only ONE of the 20 dogs used came back with 50% or more of any one breed -- so only ONE fell within the 90% accuracy range. So, essentially,we cannot have a lot of certainly of the actual DNA results of almost any of the dogs in the study. However, with the other 19, we can be 90% certain that the really are very mixed breed dogs and not predominently any one breed. I think this is very important in how the results are analyzed.
The Results
While this study is far from conclusive because of the very small sample set of dogs, I do believe the initial results are very interesting.
Based on the study results, for 7 of the 20 dogs, more than 10% of the responents thought that the dog was "probably" a purebred dog. For three of the 20, 19% or more of the respondents thought the dog was probably a purebred dog (one of these three was the only dog in the study with a mix of 50% of any one breed - Miniature Pincher - and the majority of respondents incorrectly ID'd the dog as predominently Carin Terrier).
Also of note, there was agreement among 50% or more of the respondents in the predominent breed in only 7 of the dogs -- and in 3 of them, the visual ID did not match ANY of the DNA identification. In the other 13 dogs (65%) there was no majority guess among the panel.
In 14 of the 20 dogs used, less than half of the guesses included a breed that was even detected by the DNA results. And for one of the dogs, exactly zero of the 859 respondents correctly identified a breed of dog in the mix (and this was the dog with highest breed concentration).
Discussion
It's important to note why this data is important. In the United States, more than 40% of the canine population is mixed breed.
For decades, the only possible way to identify mixed breed dogs was through visual identification, and many city juristictions have used such identification to influence their animal control policies.
However, we are now getting a lot of science-based data on the efficacy of such ideals, and the results don't support visual breed ID as a basis for policy:
- Visual ID of dogs is highly inaccurate when compared to DNA results
- The Visual ID of mixed breed dogs is highly subjective, as most 'experts' don't agree on the breeds based on looks
- Even those well-educated in the field are susceptible to judgment biases
Thus, statistical data that has often used to promote breed-specific policies is, and has been, based on visual breed identification that is proving itself to be highly subjective and inaccurate. And if public policy-makers want to rely on scientific and accurate information for their decisions, then the best solution will be to focus solely on behavior-based ordinances that target how dogs (and owenrs) BEHAVE, not how they look.
Here's a link to the entire Voith Study (very detailed)
Here's a link to the National Canine Research Council's overview of the study.
Here's a link to a very nice visual chart that shows the dogs and the study results for the dogs.
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