This is because the Chihuahua breed standard describes two head types:
* Apple Head: This type has a very short, rounded snout and a domed forehead, giving it a characteristic "apple" shape.
* Deer Head: This type has a longer, more pointed snout and a less domed forehead, giving it a more refined, deer-like appearance.
Both types are considered acceptable within the breed standard, but the apple head is more common.