Mismatched friends make great stories: the Mastiff who adores his family’s Maltese. The little Yorkie that bosses around the family’s big Rottie. But we also hear anecdotes about some individual dogs recognizing, or gravitating toward, their own breed. My German Shepherd Dog, Maverick, for example, ignored every dog in his obedience class except the other two GSDs, whom he watched closely (and tried to lead me toward!). Some individuals within a breed tolerate their own breed more readily than other breeds.
“Many Chihuahuas, for example, are unsure around other breeds and yet at ease with Chihuahuas,” says Chihuahua breeder Allynid Bunten of San Antonio, Texas. “And in general, Chihuahuas bark at anything that looks different, so expect more barking at non-Chihuahuas.”
Whether the dogs are noticing size, countenance, physical features, or mannerisms, is up for discussion. But science has made some interesting progress in understanding an even bigger picture: Dogs of any breed recognize each other as the same species.
Now this finding is rather remarkable given we’ve bred the canine species in such a wide range of sizes and appearances. It’s difficult imagining a huge Great Dane looking over at a small Rat Terrier and saying, “Ah, you and I are one in the same.” But research now indicates this is exactly what happens.
In French studies dogs were able to pick out dog faces of any breed (or breed mix) from a selection of other animal faces. The study was done with only visual cues; dogs couldn’t rely on their sense of smell or hearing. The results indicate that dogs form a visual grouping of “dog” despite the diversity in breeds. Why is this important? Well an animal’s ability to group himself with others is significant for social and reproductive reasons. In the dogs’ case, human involvement has controlled much of the breeding. But as rescue groups across the nation will attest, stray dogs do find one another and reproduce.
So yes, a Chihuahua can see a photo of a Newfoundland, Golden Retriever, or Greyhound, and group them with himself. But he may view his own breed as an important subset, for when he heads to the dog park, he may still seek out Chihuahua friends!