When I was checking out testing for Bella, I did a lot of searching for this kind of information. The genetic testing done by Mars, Inc. was developed in-house, and is proprietary information, although in order to produce a marketable product, they have to produce results that are useful to veterinarians. After I'm finished with this post, I'll check the research literature again to see if Mars testing has been independently checked for accuracy. I do know that Mars labs are federally inspected, and that they maintain high standards. But then again, the federal government's inspection programs are tightly strapped for money, so it's hard to say how good a job federal inspectors can do.

Now for some good news :). I just got off the phone with the folks at Wisdom Panel, and they pointed me to the following link for up to date information on genetic diseases that can currently be tested for:

Information on Diseases & Conditions | Genetic Health Analysis

Note the following disclaimer:

"ROYAL CANIN® Genetic Health Analysis™ does not screen for any diseases or conditions. Our improved dog DNA test has the added capability of serving as a warning flag, allowing us to inform veterinarians through our report about potential health conditions that may exist in dogs with certain predisposed breeds in their background. It is then up to the veterinarian to confirm the existence of a condition through the appropriate canine diagnostic laboratories."

That means that the Royal Canin test does not actually test for genetic diseases, but the link I gave does give a list of diseases for which your vet can have DNA samples sent out for testing, and it gives a link to the labs that do testing for those particular diseases. This is a fantastic resource because it has all of the information about genetic diseases in one place, including references and links to other testing facilities.

The most recent article I can find about comparisons between Wisdom Panel testing and visual breed identification is here:

Comparison of Visual and DNA Breed Identification of Dogs and Inter-Observer Reliability

I think it is behind a pay firewall for most people, so I'll paste the most interesting conclusions here. (Parts that I left out are shown by dots like this ...) My conclusion from this is that DNA testing for breed analysis is currently about 85 to 90% accurate, but visual identification of breeds is much less accurate than that:

Abstract Until the recent advent of DNA analysis of breed composition, identification of dogs of unknown parentage was done visually, and visual identification is still the most common method of breed identification. We were interested in how often visual identification of dogs by people, assumed to be knowledgeable about dogs, matched DNA breed identification and how often these people agreed with each other (inter-observer reliability). Over 900 participants who engaged in dog related professions and activities viewed one-minute, color video-clips of 20 dogs of unknown parentage and were asked to identify the dogs’ predominant breeds. For 14 of the dogs, fewer than 50% of the respondents visually identified breeds of dogs that matched DNA identification. Agreement among respondents was also very poor. Krippendorf’s alpha was used to examine the reliability of the most predominant breed (selected across all dogs identified as mixed breeds) for all respondents, yielding alpha=0.23. For only 7 of the 20 dogs was there agreement among more than 50% of the respondents regarding the most predominant breed of a mixed breed and in 3 of these cases the most commonly agreed upon visual identification was not identified by DNA analysis.



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1. Introduction


The breed by which a dog is identified has important implications and ramifications. Breed identification is used in public health journals, veterinary medical records, lost and found notices, licensing documents and animal shelter descriptions. How a dog is identified also influences how people interpret a dog’s behavior. World-wide, public and private regulations and restrictions have been enacted that regulate dog ownership, euthanasia, availability of liability insurance, and access to housing. These rules may specify specific breeds, mixes of these breeds, or any dog that resembles these breeds. We were interested in how often visual identification of dogs by people assumed to be knowledgeable about dogs matched DNA breed identification, and how often these people agreed with each other (inter-observer reliability).

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Our personal observations of discrepancies among people who attempt to visually identify the breed composition of dogs prompted this study. We were interested in how often visual identification by people assumed to be knowledgeable about dogs was in agreement with DNA identification, and how often people agreed with each other (inter-observer reliability). We felt this was important because of the potential ramifications of misclassification of dog breeds in published databases which drive public and private policies as well as people’s perceptions of the behavior of individual dogs.
People who engage in professions or services that involve dogs are one source of identification of dogs of unknown parentage. They are in a position to provide their opinion to owners about the possible breed or predominant breed of their dogs. They may also directly assign a breed identity to dogs and enter their opinions on office forms and/or records. Either way, these identifications have the potential to be entered into national databases which are used for prevalence statistics on dogs’ breeds.

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2.2. Source of Dogs


Twenty privately-owned dogs of unknown parentage were selected for the study from a pool of dogs that had been volunteered by their owners to participate in dog breed identification studies[26]. Forty of 50 volunteered dogs met the entrance criteria of being mature enough to have fully erupted canine teeth, having been obtained from a shelter, rescue, animal control or similar adoption agency, and being available on a specific day to be videotaped and have blood drawn.
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2.3. DNA Analysis


Two ml samples of heparinized blood from each dog were immediately refrigerated and sent on the same day on cold packs by overnight shipment to MARS VETERINARYTM Lincoln, Nebraska for DNA analysis. There were 130 American Kennel Club (AKC) registered purebreds in their database and the laboratory reported “an average of 84% accuracy in the first-generation crossbred dogs of known parentage”[22],[23]. Contributions of ancestral breeds less than 12.5% were not reported.


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3.2. Comparison of Visual Identification and DNA Breed Identification


The DNA analysis indicated none of the dogs were purebreds and most respondents identified the study dogs as mixed breeds. See Table 3. However, 7 of the 20 dogs were visually identified as probably purebreds by ten percent or more (range 10% - 25.4%) of the respondents. An average of 9.2 % (1701/18408) of the responses were “yes” to the question “Do you think this dog is probably a purebred?”.


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3.3. Inter-Observer Reliability of Visual Identification of Most Predominant Breed of Dogs Identified as Mixed Breeds


Agreement among the respondents was also very poor, see Table 5 and see appendix. There was agreement among more than 50% of the respondents regarding the most predominant breed of a mixed breed for only 7 dogs and for 3 of these dogs the visual identification did not match any (either major or minor) DNA breed identification

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4. Discussion


This study reveals a wide disparity between DNA and visual identification of the predominant breeds comprising a dog. It also indicates a low level of agreement among people regarding breed composition. Those of us in the animal care services have always remarked on the differences of opinions regarding what breed a dog is but few are aware of how little agreement there is or how often one’s own opinion could be wrong.
The wide range of responses by the participants are compatible with research and theories pertaining to judgments of probability based on partial information[36-42]. Identification of the breed composition of a dog requires recognition and recall, both of which are influenced by a multitude of variables, such as perception, knowledge base, memory, recent or salient experiences with the subject matter, and cognitive abilities involving categorization, sorting, matching and recombination of features.
Identification is affected by what features (stimuli) a person notices and how much weight the person attributes to those features. For example, some people may attend to the hair coat and color pattern of a dog, while others focus on size, shape of head, or whether or not the tail is curled. The ease with which people notice a feature enhances recall and increases the weight that is placed on that feature. For example, so much significance is placed on any black pigmentation of a dog’s tongue that, regardless of the morphology of the dog, it is usually identified as a Chow Chow or Chow mix. The frequency with which people are exposed to the names of specific breeds of dogs and their perception of the population of specific breeds will also influence prediction. Interestingly, the literature indicates that well educated professionals are as susceptible to judgmental biases as are the lay public[36],[37],[43],[44].
The low percentage of agreement between visual and DNA identification may be partially explained by perception biases. However, DNA identification of the proportion of purebred breeds in mixed breed dogs is not perfect either, nor do the laboratories that provide such analyses claim to be infallible. The average accuracy of identification of the breeds in an individual dog can be expected to decrease as the heterogeneity of its ancestors increases. Canine HeritageTM states that their accuracy of identification of known registered purebred dogs is 99%[45]. Wisdom PanelTM currently reports a 90% average accuracy of identification ofF1 crosses of known registered purebred dogs[46].

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5. Conclusions

The disparities between visual and DNA identification of the breed composition of dogs and the low agreement among people who identify dogs raise questions concerning the accuracy of databases which supply demographic data on dog breeds, as well as the justification and ability to implement laws and private restrictions pertaining to dogs based on breed composition.