Chihuahuas are alert, energetic companions that make excellent pets for adults and families without young children. While the Chihuahua Club of America officially recognizes only two types within the breed, divided by coat length, you can break down Chihuauas unofficially according to other traits as well.
Chihuahuas are tiny dynamos that love to be with their owners and are typically attentive and devoted to them. The American Kennel Club breed standard says Chihuahuas should have “attitudes of self-importance, confidence, self-reliance” much like those of terriers. They have round, apple-shaped heads with pronounced domes; full, expressive eyes; and large, erect ears that give them an alert, interested expression. Chihuahuas should always have long tails, and the way they carry their tails reflects their mood.
Chihuahuas come in two coat types. The first type, and the one most people are familiar with, is the smooth coat. On smooth-coat Chihuahuas, the coat is short over the entire body, though it may be heavier around the neck and tail areas. Long-coat Chihuahuas should have full, long coats, often several inches long, covering their entire bodies. It is especially noticeable around the ears, around the backs of the legs and along the tail. If your dog has long hair on his back and sides, he’s a long-coat Chihuahua; otherwise, he’s the short-coat kind.
The Chihuahua Club of America states that Chihuahuas can be any solid color, including black, white, cream, red, blue, gold or silver. If your dog is any of these, or of another single color, he is a solid-color Chihuahua. He may also be one color that is marked or splashed with one or more other colors. Within the breed, tricolor dogs are common; these dogs typically have a lot of black and white on their bodies. Tricolor Chihuahuas are also marked with tan points in various places, usually above or near the eyes, on the ears and on their legs.
According to the AKC, the maximum allowable weight for a Chihuahua is 6 pounds. This is the only recognized size distinction for Chihuahuas; it's the difference between a dog that can be shown at AKC events and one that is too big. Sometimes breeders and others sometimes label their smaller dogs, those under 3 pounds, as teacups or pocket dogs. The "teacup" designation is not an accepted division, though, but more of a sales tactic to convince buyers that they are getting a very small dog. Such dogs may have significant health issues, especially as puppies, and are particularly at risk for developing hypoglycemia and dying quickly if they aren’t fed properly.