Deer and apple head chihuahua

Chihuahuas are the smallest breed of dog on the planet. These jovial little clowns come in long- and short-haired varieties, and may be designated as deer-headed or apple-headed, based on the overall shape of their skulls.

Deer-Headed Chihuahuas

Deer-headed Chihuahuas have longer, more angular faces than their apple-headed counterparts. They have elongated muzzles and narrow faces, with skulls that resemble wedges of cheese instead of apples. Deer-headed Chihuahuas are a deviation from the American Kennel Club standard, which states that the dog should have a "well-rounded 'apple dome; skull.” The loveable little dog in the Taco Bell commercials is the most famous example of a deer-headed Chihuahua.

Apple-Headed Chihuahuas

Apple-headed Chihuahuas are the epitome of the breed. They are the closest thing to the standard. They have domed, apple-shaped skulls. Apple-headed Chis have short, wide muzzles and a small depression, also known as a molera, in the middle of their foreheads. This variation of Chihuahua has more dental issues than deer-headed Chis, due to the lack of space along the gums. Another hallmark of apple-headed Chis is the full, deep stop at the top of the muzzle. The chihuahua poodle mix also called the chipoo is famous cross of the chihuahua and poodle.
http://www.aboutdogfacts.com/apple-head-chihuahua-care-facts-and-pictures/
http://www.aboutdogfacts.com/chihuahua-poodle-mix/
Facts about dogs