“You know, Chihuahuas aren’t actually dogs. They’re a kind of fox,” announced an acquaintance at a party. This woman, who owned two chihuahuas herself, entirely believed that Chihuahuas are the domesticated descendants of the fennec fox. I can understand the reason that many people might believe this: Chihuahuas do resemble fennec foxes in their superficial appearance, with long-haired Chihuahuas appearing almost indistinguishable from from their wild, vulpine counterparts.
The idea that chihuahuas are related to fennec foxes isn’t uncommon. Even the American Kennel Club, which is usually a highly credible and reputable source of information, acknowledges the belief and the resemblance between Chihuahuas and fennec foxes. As intriguing as it is to imagine that Chihuahuas are a breed of domesticated fox, this idea simply isn’t true. Chihuahuas are, in fact, far more closely related to Great Danes, dingoes, and wolves than they are to fennec foxes.
Chihuahuas are taxonomically classified with other domestic dogs, which are recognized as a subspecies of gray wolf (Canis lupus familiaris). Like other dogs, Chihuahuas are able to breed with other members within the same species. A chihuahua can readily interbreed with any variety of domestic dog, most frequently including other small varieties like terriers and toy breeds. It could even, in theory, readily interbreed with any subspecies of wolf– Arctic wolf, timber wolf, and so on.
The Fennec fox is not only a member of a different subspecies and species than the Chihuahua– it’s not even in the same genus. Chihuahuas and fennec foxes are fairly distantly related (about as closely related as a house cat and a leopard). Their similarities occur only because of a phenomenon known as convergent evolution, in which animals develop similar traits to meet similar biological needs.
A simple observation of geography further debunks the idea that fennec foxes and Chihuahuas are related. While the fennec fox is endemic to the deserts of Africa, the Chihuahua hails from Mexico, where it derives its common name. Its closest living relatives are other native Central and South American breeds like the Peruvian Inca Orchid. Its ancestor, the now nearly-extinct Mexican gray wolf, is also a much closer relative to the Chihuahua than any other fox or wolf.
As cute as it may be to imagine the Chihuahua as a little fennec fox adapted to life as a pet dog, this theory is invalid. Chihuahuas are domestic dogs to the same degree as Dalmatians, Labradors and poodles, and no amount of convergent evolution or superficial resemblance will change that. As much as a Chihuahua might look like a fox, it is– and always will be– a dog.