Traditionally the age that they go to their new home. Now weaned from the dam, they are eating solid food. They will sleep quite a bit and be bundles of energy when awake. Their puppy teeth are usually all showing by this age.
This will seem like a long phase, as it is the teething stage. It is a slow process, as first the incisors fall out and then the molars. There are early bloomers and late comers… not all pups are the same. In general, this will all be done by the age of 8 months.
Most females will enter heat for the 1st time by this young age. Some enter as young as 4 months, some as late as a year or 15 months.
During the Shih Tzu life span, the 1 year old dog is now considered to be an adult, a young adult to be exact.
If a female was breeding, now is the time to retire her from this.