Most dogs in our community are mixed breed or of unknown parentage, and when it comes to breed specific legislation, animal control personnel are making judgement calls that can sentence a dog to a lifetime of restrictions, or even death.
With the advent of DNA tests, some hoped that this question could be resolved by science. But while a DNA test can be a fun and interesting activity for the average pet owner, it should not be used to make life or death decisions for dogs in our community.
The notion of distinct breeds is a newer one in human history. All existing breeds are combinations of other breeds, and ultimately trace back to common ancestors. The DNA testing companies attempt to identify DNA markers consistent with defined groups of dogs - but these are patterns of DNA, not a definitive gene that codes for a Labrador Retriever or Pug.
In doing some research to clarify this issue, which included contacting DNA testing companies directly, we couldn't find a verifiable accuracy rate for canine breed tests. There are some claims that for purebred dogs the accuracy rate of a DNA test may be 80-90%. For the offspring of two purebred dogs they claim accuracy at the lower end of that scale. But for any other mixture of breeds? We really don’t know. It wouldn’t be impossible to find out – scientists could compare DNA test results to groups of dogs with known parentage and publish the results – but we can’t find large scale studies like this. It seems that either the research is not being done or it is not being shared with the public.
As technology progresses and as we start to see peer-reviewed research to back it up, DNA testing may give us valuable insight into our dogs, but at this time they should not be relied upon to answer the question of a dog's breed makeup.