In homes without small children, the best age for adopting any puppy, including a Shih Tzu puppy, is between the age of eight and 16 weeks. In homes with small children, waiting until the puppy is around five months old is best.
A puppy needs to be at least eight weeks old before it leaves its mother and littermates behind. The puppy learns to feed, groom and socialize by being with its mother and other puppies. By eight weeks of age, puppies can eat puppy food and no longer rely on their mothers’ milk. Waiting longer to adopt a puppy makes it harder for the puppy to adjust to its new surroundings and break any bad habits.