Melville, N.Y. ? The doggie euphemism “All-American” was coined as a politer way to say “mutt.”

It never caught on, and perhaps just as well. After a boxer named Tasha lent her DNA to scientists to map the dog genome in 2005, advances in canine genetics have continued with as much speed as a border collie on an agility course. Today, at least two companies are offering DNA tests to identify the ancestors in a mixed breed’s background. And the potential market is huge: Roughly half of all dogs in this country are mixes.

The better-known of the two tests is the Mars Wisdom Panel MX (whatsmydog.com or wisdompanel.com). Compared to its competitor, the cheek-swab-based Canine Heritage Breed Test (metamorphixinc.com, $79.95), which can identify 38 potential breeds, the Mars test uses a blood sample and encompasses 130 purebreds. That’s 27 dogs short of all the breeds recognized by the American Kennel Club, but it’s significantly less than the 335 breeds that have gotten the nod from the Federation Cynologique Internationale. (So, if you suspect your pooch is part Anglo-Francais de Petite Venerie, fuggedaboutit.)

Because it requires a blood draw, the Mars test (it was developed by the candy company that also owns Pedigree) is available only through vets’ offices. Prices are determined by vets and range from $100 to $200.

Paul Jones, senior genetics leader for Mars Veterinary, says that, curiosity aside, knowing the breeds in your dog’s heritage can help you in other areas, such as health care and training – another reason the company made the vet’s office the portal for the test. Eventually, he says, Mars Veterinary hopes to offer health-related genetics tests, either by developing its own or by licensing those owned by others.

The Mars test is based on the DNA of 13,000 dogs from around the globe. “Designer dog” breeds such as Labradoodles and puggles were also represented. Not included among the 8,000 purebreds analyzed was the pit bull, though the Mars test does have the American Staffordshire terrier, which is a subset of the pit.

The Mars test claims a 95 percent accuracy rate – that is, it is sensitive enough to detect 95 percent of the material that is there. But its interpretation of that data – the fancy term is “positive predictive value” – is 84 percent.