The mystery is over -- one of them, anyway.

I got the answer to the question everyone asks in a voice mail, informing me that my dog's DNA showed two primary breeds.

The face (and tail) that launched a thousand guesses is -- largely -- Rottweiler and chow.

Since adopting my dog Ace a year and a half ago, I'd heard dozens of possible combinations -- from the shelter where I got him, from veterinarians, from other dog owners -- but not that exact one.

Now, my two-month-long quest to find the roots of my mutt was over -- with, appropriately enough, mixed results.

As far as his past, we'd learned from our return to the Baltimore Animal Rescue and Care Shelter, known as BARCS, that Ace was a stray, found on the street by a citizen in the 21229 ZIP code who called animal control. Ace weighed in at 50.9 pounds, spent 17 days in the shelter and drew 302 clicks on during that period.

Our trip to 21229 was unfruitful, though Ace made some new friends. Everybody liked Ace; but nobody knew him.

And our visit from an animal communicator -- though she said Ace revealed to her that he was abandoned by his family when he grew too big and proved too gentle to be the fighting dog it wanted -- was not the kind of hard-and-fast, twice-confirmed, indisputable-as-DNA evidence we journalists most like to be fed.

The DNA test I administered and popped in the mail had led to probably my strongest finding -- that Ace was Rottweiler and, more surprising, chow, a dog that, while curly-tailed, is short in stature.

Do the test results mean that Ace is a product of a purebred Rottweiler and a purebred chow? Not necessarily. It just means that, of the 38 breeds MMI Genomics' $65 Canine Heritage test checks for, Rottweiler and chow are the only two that showed up.

More likely, if purebreds were involved at all, they lay further back in his lineage, along with many other breeds not on the list of 38.

So, can I call him a "chow-weiler?"

"If you wanted to be exact you could say the genetic structure of his DNA reflects that of a purebred Rottweiler and a purebred chow," said Sue DeNise, vice president of genomic research at MMI Genomics.

"Or you could say he's a mix of breeds, and that those include a high extent of Rottweiler and chow," said Dennis Fantin, its chief of operations.

The people at MMI Genomics point out that, while the biggest appeal of the new test may be the fun of it -- the joy that dog owners get in satisfying their curiosity -- it can also be useful in understanding your dog's health and behavior.

Chows, for example, can be willful, introverted and obstinate -- in addition, of course, to their many good traits. While highly loyal, they can be detached -- a remnant, some dog books say, of the way they were once treated long ago in China, when they were used for fur and meat.

Rottweilers, some dog manuals contend, require firm and careful training to ensure they don't become overly aggressive, especially around other dogs. While those I've met have all had sweet dispositions, the muscular build and large body of the Rottweiler, as well as their use as guard dogs, have given the breed a reputation, among some, as dogs to be feared.

With dogs, as with people, the reputations are sometimes out of proportion with the reality.

It is for just those reasons that MetaMorphix avoided including pit bulls in the 38 breeds they test for. With some cities considering legislation against the breed, the company worried that its test could be used to terminate animals.

Mulling the outcome
Borrowing a chapter from the animal communicator -- I took some time to fill Ace in on his heritage.

I told him that, even though he doesn't have the breed's lion-like mane and trademark blue-black tongue, he is part chow, a proud and regal dog that originated in China, and part Rottweiler, originally bred as a herd dog in the German town of Rottweil.

I assured him he would never be worn or served for dinner, and that it was unlikely that he would be called upon to herd or guard. Like most dogs today, he has no job and only one purpose -- companionship.

He seemed bored by the history and unimpressed with the handsome certificate MMI Genomics sent declaring him part chow, part Rottweiler. I sensed neither celebration nor alarm about the test's results.

While certain breeds are prone to certain medical problems -- many of them a result of limiting the gene pool in the effort to breed champions -- some veterinarians say mixed breeds avoid many of those problems, and some say that what particular breeds are in a mix is not usually essential information.

"I don't know that knowing exact breed is going to get you any information that just basic wellness exams on a regular basis would do just as well," said veterinarian Jill Shook of Citypets Veterinary Care and Wellness.

"For the curiosity purpose of it, I think it's neat that it's available now, but from a medical standpoint, ... I don't know that I would tell people to go out and have it done."

BARCS Director Jennifer Mead said the test could cut down on complaints the shelter receives from people who get a subsequent, and differing, opinion on what their dog is.

"People come in here and we tell them one thing, then they get to their vet and are told something else," Mead said, acknowledging that guessing breeds is often an iffy proposition.

The shelter couldn't afford to pay for the test but could possibly pass on its cost to potential adopters who request it, she said.

What we've learned
So what have we learned from all this?

Not much that will benefit Ace. Any future health problems he has will probably stem more from his size than his breeds.

Knowing what breeds are in a dog can be helpful in some cases. In Ace's, though, being a mystery mutt may be a benefit.

Chow and Rottweiler are both breeds that, like pit bulls, Akitas and German shepherds, often, wrongly, have bad reputations. Had he been correctly labeled at the shelter, as opposed to the erroneous "hound mix," there might have been no takers, and he could have gone on to the fate that befalls 3 million to 4 million cats and dogs in the U.S. each year -- euthanasia.

Six million to 8 million cats and dogs end up in shelters nationwide every year; only about half are adopted.

Maybe what we've learned is that some mystery is good; that, while solving one can be fun, unsolved mystery can be savored, and even useful, as well.

Maybe we've learned that labels shouldn't be taken too seriously: that our need to categorize things -- dogs, people, music, art -- shouldn't get in the way of simply enjoying them for what they are.

Maybe we've learned that, while nature and nurture both play roles in shaping dogs and humans, neither totally dictate what we will become.

And maybe we've learned that DNA -- distinct as it may be -- doesn't solely define a dog, or a person, any more than your ethnicity, religion, neighborhood or socioeconomic status do.

Nothing solely defines you, except maybe your soul.

Black dog, white dog, brown dog, yellow dog, big dog, small dog, purebred, mixed breed, it just doesn't make all that much difference.

As long as you're a good dog.