Shadow and Tiger, our two Chihuahua puppies, are littermates, yet they have two distinctly different head-types. Shadow is a “Applehead” Chihuahua and Tiger is a “Deerhead” Chihuahua. I find this fascinating. I don’t even recall which type their mother was, but I saw her when we picked them up. The owner may have mentioned the head-type that their father was too, but I don’t recall that either. I should have taken notes, darn it. Anyway, here’s what the experts say on the history of the two Chihuahua head types:

Somewhere throughout the Chihuahua’s history, the breed separated into two variations: the apple head and deer head. We don’t when this genetic evolution occurred, nor do we know how. Pre-Columbian artifacts discovered in Central America depict small dogs with both apple and deer-shaped heads, suggesting this evolutionary split occurred before the Europeans discovered the New World.

Some breed experts theorize that a small ancient dog known as the Techichi is the Chihuahua’s true ancestor, while the deer head variety is a cross between the Techchi and the Chinese Crested. Others believe the Techichi is the deer head’s true ancestor. Regardless of how it happened, there are now apple head and deer head Chihuahuas.

In addition to this, they say: Don’t assume that breeding two apple head Chihuahuas will result in a litter of all apple heads, or vise-versa for deer heads. When breeding two Chihuahua of the same variety, there’s always a chance that one or more puppies in their litter will be the opposite variety.

So I guess no matter which type of head the mother and the father had, they could always have ended up as they are now. It’s just the luck of genetics, just like human babies. I was just curious if it’s rare to have both types in the same litter, but it sounds like it’s not.

But if their head-type is any indication of intelligence, so far (for us at least) the deer-head seems somewhat less intelligent than the apple-head. Tiger is pretty “wimpy” compared to Shadow and is very much a follower and not a leader. He’s learning, but much slower, it seems, that Shadow. That goes for both pad-training and command training. I think he’s learning a lot just from watching his brother, then he eventually starts doing them properly himself. Then again, maybe he’s actually smarter than we think, and he’s just extra cautious, working things out completely before exercising them and showing his talents. Yeah, right.