The average breeding age for a yorkie is eighteen months. A dog younger than this cannot breed because he/she is not mature enough. Check the birth certificate of your yorkie before deciding to breed him because you want to avoid all kinds of complications that can harm your dog.
You need to be sure that the Yorkie is healthy enough to breed. Since teacup yorkies are tiny in size, they are vulnerable to many health problems. You can go ahead with the breeding only if they are in the perfect state. Check with a reputed veterinarian. An unhealthy dog will pass on the defect to his/her offspring.
Choose a partner that belongs to the same breed. A partner from any other breed will introduce genetic defects into the race and it will not even remain pure. Search out a teacup yorkie for your dog of the opposite sex.
Wait for the heat period of the female member. This heat period occurs twice an year and lasts for 21 days. Look out for this heat period by observing the female's physique and temperament. Usually the vulva increases in size and occasionally also has a discharge. During this heat period, let the male and female yorkies be in contact and allow them to mate. To be sure of the pregnancy, make them mate several times. You will only be able to tell if the yorkie is pregnant or not after several weeks. Hopefully if everything goes as planned, you will be the proud owner of a baby yorkie by two months.