Is it a Yorkie? Is it a Pom? No it's a Rottie-Poo!

Designer dogs are all the rage right now. They come with as many cool and unusual names as physical appearances. As a sampling we've got the Cockapoo, Schnoodle, Shorkie, Labradoole and my current favorite -- Chiweenie (that's a cross between a Chihuahua and a Dachshund). Say it with me...Chiweenie. Too much fun!

Bull Mastiff and French Bulldog

Of course, these exotic designer dogs are not a new concept. Mixed breed dogs--some would call them "mutts"--have existed before the AKC purebred was even contemplated. The product of mating two totally different breeds has traditionally been considered either an "oops" or a part of the process of creating an new entirely new breed. For example, the cuddly petite French Bulldog is a descendant of the massive Mastiff breed with deliberate selection for size, shape and temperament being done over centuries.

Genetics is a fascinating subject. Sometimes a mixed breed dog shows physical characteristics distinct to its various ancestors--perhaps having the satellite dish ears of a Chihuahua, the thick stubby legs of a Bassett Hound, the brown ticking hair of a German Shorthair Pointer and the icy blue eyes of a Husky. Many times, however, the individual breed traits nearly disappear into whatever is the dominant feature. The ubiquitous humane society moniker "lab mix" or "shepherd mix"is a testament to the fact that many Heinz 57 dogs end up looking a heck of a lot like one these common ancestors. In fact, I currently see several Labrador Retriever-Springer Spaniel puppies in my veterinary practice. If I didn't know better, I'd think they were simply black or chocolate Labradors; you really have to search for the Spaniel characteristics.

A wonderful scientific development in the veterinary world is the Mars Wisdom Panel, an affordable genetic test that not only identifies the ancestry of a mixed breed dog but can also test for numerous genetic diseases. It is nearly always a surprise the breeds that pop up in this genetic test.

Grimm,
the Yorkie-Papillon-Cocker-Rottweiler

Recently, we tested a adorable black scraggly-haired small-breed puppy named Grimm. We guessed he was some kind of terrier, most likely a Yorkie. The actual Wisdom Panel results blew us all away. Grimm's genes reveal that his ancestry indeed includes a Yorkshire Terrier. He also can claim a Papillon, Cocker Spaniel--and get this!--a Rottweiler as his grandparents.

Knowing Grimm's heritage does not just satisfy the owner's (and veterinarian's) curiosity. It also provides valuable signalment that is useful in understanding his risk of developing certain diseases. Fortunately, Grimm tested negative for the genetic diseases included in his Wisdom Panel Professional. However, there are many diseases seen frequently in certain breeds that are not easily testable, and now as Grimm ages, we can use his breed information to predict his  susceptibility to these conditions.

It may seem implausible that a Rottweiler and a Cocker Spaniel reproduced and subsequently passed on their genes to a tiny Terrier. It really should not be surprising that raging hormones (in any species) can create some very unexpected situations. This summer I was privileged to care for a litter of Boxer-Cocker Spaniel pups. The mom (thank goodness) was a very large Boxer and the dad, a medium-sized Cocker. The pups are adorable, with the larger bone structure of a Boxer and the soft, floppy facial features of the Spaniel.

New owners of mixed breed dogs often seek an educated guess from their veterinarian regarding their dog's heritage. I have to be honest. Having witnessed the offspring from unlikely pairings and reading the jaw-dropping reports on official genetics tests has made me much less confident in my guesses. After all, I would never in a million years have guessed that Grimm had a Rottweiler grandparent.