The smallest breed but be careful of domed shaped heads it shows an illness. I've found them to be yappy and can have small dog syndrome due to lack of training and not being treated like a dog. Stay away from Teacups the are just dogs born too
Chihuahuas are excellent pets, but a dog owner must bear in mind that the Chihuahua lifespan is shorter compared to human lifespan. That said it is important that the owner to make sure that his/her Chihuahua has a long and happy life.