People choose to breed dogs for a wide variety of reasons, whether to make some money or simply because they like the breed. Before you breed your shih tzu, make sure you know what you're doing. Though not hard, it's a process that can easily wind up causing more trouble than it's worth if you're not prepared.
Consider your reasons for breeding your dog. Is it for the money? If it is, you might want to rethink your plan, as breeding can be expensive--so expensive that breeders consider themselves lucky if they break even. You have vet costs to consider, shots for the newborn puppies, food, and the hassle of finding owners for the dogs. If you want your children to experience the miracle of life, remember that that miracle is a painful process, and it's no less painful for dogs. They also often choose to give birth in the middle of the night, when there is nothing going on. But if you're breeding because you feel your dog can contribute to the breed, then by all means go ahead.
Take your dog to the vet to make sure it's healthy before you breed it. Every breed has health problems that can be detrimental, or at least bothersome. Shih Tzus are prone to ear, eye and respiratory problems. Both male and female dogs need to be checked by a veterinarian before breeding to make sure they don't have those problems, and are less likely to pass on these unfortunate traits. It's also important to make sure the dogs don't have any other diseases or illnesses, like rabies or brucellosis.
Find a dog you can breed with your dog. Keep in mind that if you own the female dog, you will need to pay the $300 or $400 stud fee. You can look in the classifieds or put an ad in the newspaper, check out dog breeding magazines, put up a flier at your local pet store or talk to your veterinarian. Find another shih tzu whose owner is close by, but be willing to drive.
Keep track of when the female dog is in heat. Most females go into heat two times a year. They should not be bred before they are two years old. Make sure you (or the owner) are familiar with her cycle. You can tell when the female is ready to mate, because when you pet the area just above her tail, she'll move her tail to expose herself to you. You may need to hold the female's head so she doesn't run away from the male, doing damage to both dogs.
Bring the dogs together every other day until the female will no longer accept the male. Keep in mind that the female should be kept separate from all other male dogs at this time, as she can release several eggs. She can end up carrying several different puppies with different fathers if she's with more than one dog.