Shih Tzus are sweet and playful dogs who are small but can have big attitudes. Their personalities and portable size makes the little dogs popular, and many people become lifelong fans. If you decide to breed your Shih Tzu, make sure you're prepared. One of the key supplies is a whelping box for the mother to use for nursing the puppies after they are born.
Choose a box to use for the whelping. This box should be large enough for your dog to lie down, stand up, turn and shift comfortably without crowding or endangering her puppies. A safe bet is to use a box about twice as big as the mother dog.
Put the box on the floor and measure it against your Shih Tzu. Cut out one side of the box open up the front. When you're cutting out the front of the box, leave a lip at the bottom that comes up to the mother's dog stomach. This lip is designed to keep the puppies inside the box while allowing the mother to come and go as she pleases. The lip should not be so tall that it scrapes her stomach or her nipples, but it should be tall enough that the pups won't be able to get over it until they are older. Because a Shih Tzu stands between 8 and 10 inches tall, this lip should be about 3 inches.
Fill the whelping box with blankets and put it in a safe place. Make sure that your dog knows it's there; this will be her nest, the place where she gives birth. One of the first signs of impending labor is when a dog starts nesting, so make sure that the whelping box is placed in the area where the birth will be taking place.