Because the Chihuahua is the smallest dog breed in the world, breeding a Chihuahua differs than breeding other, larger dogs. It is also very different than breeding other toy dogs such as the Pomeranian or Toy Poodle.
If you are thinking of breeding your Chihuahua to produce top quality pups, think this over again. It takes only a very few male stud dogs to breed, but a larger number of female dogs if you are to have your own program.
In most cases, only top winning Champion male dogs are considered to possess the high level of quality needed to qualify as a registered stud. If your female dog is not registered, an honest breeder would not allow a planned pairing to take place. Therefore, you would want to begin with an AKC, high quality female.
The Chihuahua is prone to needing to have a Cesarean. This can be quite expensive and it can compromise the health
of the dog.
You must have all needed supplies, you must have time (breeders spend countless nights awake, hand feeding little puppies that cannot get milk from the dam and without constant nutrients would quickly develop Hypoglycemia), possibly dealing with post-pregnancy health issues for the dam, and you must have dedication, whether breeding one litter or wanting to become a professional breeder.