Size
Breed standards for the Chihuahua do not generally specify height, only a weight and a description of their overall proportions. As a result, height varies more than with many other breeds. Generally, the height ranges between six and ten inches at the shoulders. However, some dogs grow as tall as 12 to 15 inches. AKC show dogs must weigh no more than six pounds. Chihuahuas bred as companions rather than show dogs can range above these weights, up to ten pounds, or even more if they have large bone structures or are allowed to become overweight.
Coat and Color
The AKC recognizes two varieties of Chihuahua: the long-coat and the smooth-coat (also referred to as short-haired). They are genetically the same breed, and are often present in the same litter, though in many kennel clubs they are judged in separate categories.
The term smooth-coat does not mean that the hair is necessarily smooth, as the hair can range from having a velvet touch to a whiskery feeling. Long-haired Chihuahuas are actually smoother to the touch, having soft, fine guard hairs and a downy undercoat, which gives them their fluffy appearance. Unlike many long-haired breeds, long-haired Chihuahuas require no trimming and minimal grooming. Contrary to popular belief, they also typically shed less than their short-haired counterparts.
The AKC standard allows for all colors from solid blacks to solid whites, spotted, or a variety of other colors and patterns. Classifying Chihuahua colors can be complicated due to the large number of possibilities. Examples would be a blue brindle or a chocolate and tan. Colors and patterns can combine and affect each other, resulting in a very high degree of variation. That said, the classic Chihuahua color remains fawn. No color or pattern is considered more valuable than the others. Although blue is considered rare, it is all just a matter of personal preference.