Instructions
Find out the exact location of the kennel. This is important in order for you to verify the existence of the kennel and also that there is a facility there capable of housing dogs. Sometimes people will actually run puppy mills or buy dogs "in bulk" from these mills and then ship them out all over the country. These are often true yorkies, but they have likely been neglected and can have serious health problems that you will not be able to identify until after your pet arrives. They also can have learning disabilities and be mentally unstable.
Interview the breeder personally. A good, responsible breeder will have spent some time with your dog and will know a little about your new yorkie. They should be able to tell you about any vaccinations that your pet has had, any house training she may have learned and even a little about the personality and care for that particular dog.
Get a signed contract concerning your puppy's health. This contract should state any common ailments of the breed and provide a limited window for returning your dog should you find out that it is mortally ill or in the sad case that your puppy dies about the time you get it home. This will protect you in the event that the breeder's kennel is infected with parvo or other diseases that can kill a dog. The contract should also contain any parameters on spaying and neutering so that you and the breeder are both clear about what can be done with your yorkie.
Take your potential pet to the veterinarian immediately. You must get your yorkie's health evaluated at once. Yorkies are fairly hardy as far as toy breeds go, but they can come with serious, life-threatening issues that in some cases are untreatable. The problem may not be evident in a puppy in a kennel, but your little dog could die just a few days after you get her if you do not find out about these issues ahead of time.
Search online to find reviews or comments about the breeder. Red flags should be things like a lot of people finding out their puppies were ill after they brought them home or notes about the poor condition of the kennel itself. Although you may desperately want to get your puppy out of those conditions, remember that if you pay a breeder running a mill hundreds of dollars for a mistreated dog, that will just encourage them to continue breeding in the same irresponsible way.
Do not buy from an overseas breeder unless you have a personal reference for their integrity. There are many notices and websites online where the seller or the breeder claims to live in a far-off country and only wants fifty or a hundred dollars for the yorkie, but requires you to pay several hundred in shipping. The odds are good that if you send this money you will never see your yorkie because the dog does not exist. If you do receive a dog, it may not even be a yorkie and it will likely be mistreated, malnourished or worse.
How to Buy a Yorkie From a Breeder
Buying a yorkie from a breeder can be a good move. You will know all about your dog's history and health issues--if there are any--as well as knowing how the dog was raised in many cases. Also, you will be able to show your yorkie should you wish to do so because a breeder will give you his papers. However, you must do some careful research before you buy your yorkie--no matter how much you love him--in order to make sure that you are doing the right thing and supporting a kennel that deserves your money.