Things to look out for when buying a new puppy
Puppy mills- puppy mills are unethical they breed dogs purely for profit. Puppies bought from a puppy mill are likely to be unsocialized and may have temperament problems, as well as medical problems. Buying a puppy from a puppy mill supplies the cash to keep the puppy mill going. So if your tempted to buy a puppy mill puppy out of sympathy, don't you will be responsible for providing the profits to keep the mill going.
Puppy mills often try to disguise themselves as responsible breeders, as they know any other way the potential buyer would run a mile. To spot a potential puppy mill look out for people who have a large number of puppies available, remember an average chi litter is only about 3 pups. Also be wary if they also sell other breeds of dogs. When you go to visit the puppy ask to see the parents, the sire may have bin a stud but there is no excuse for not being able to show you the dam.
When meeting puppy and parent(s)- Be wary if the pups and dam seem overly timid or aggressive, its normal for the dam to be wary when you first enter the house. Check to see how the dam is with the owner, if she is timid or aggressive even with them, then its usually a very bad sign, remember puppy mill dogs are often kept in cages with little socialization.
With the puppies check for sign of bad health, check for fleas, runny eyes or discharge in the ears. Use your nose too, as you will be able to tell from this how the puppies are kept, and if the puppies smell too nice (eg shampoo) then also be suspicious as there is usually no need to wash young puppies.
check the living quarters Ask to see where the puppies are kept, lots of cages, smell and dirt obviously a very bad sign. However do not be put off if the dam is kept in a cage/crate with the pups, as chihuahuas are often crate trained and kept there for their own safety
Ask questions and expect questions in return- a good breeder will know there stuff and should be able to answer all your questions.
Things you should ask the breeder include-
-What age are the willing to let the puppies go?-be wary of any one selling pups below the age of 10 weeks.
-Will the puppies be wormed and vaccinated?- the puppies should have bin wormed and also possible have had their first vaccination. The breeder should tell you when you should next worm and vaccinate the puppy.
-How is the breeder socializing the puppies?- early its normal for the pups to remain only with the dam, but then the breeder should take steps to socialize the puppies with humans.
-Ask the breeder about themselves- how long have they been breeding? how may litters a year do they have, how many dogs do they own?, be wary of signs of a puppy mill
A good breeder will want to ask you question, if they care about their puppies they'll care who gets them.
Buying puppies on the Internet- People who are desperately seeking a puppy can get over excited when they think they've found one, which makes them a good target for con artists. Remember you don't actually know anything about the person, they could have given you a false name and address and could easily disappear when you give them a deposit or actually pay for the pup. These people will usually want to ship the pups, so that you have to pay first.
Please ad to this post any other advice you have, aswell as any cons, puppymils or bad breeders out there that you are aware of
Edited 1/14/2010 to add a few good links to check out
http://www.phouka.com/dogs/bdr_irres.html
http://www.phouka.com/dogs/bdr_questions.html
http://www.phouka.com/dogs/bdr_owner.html